CN103174391B - A kind of control system of Electro-hydraulic drive coiled tubing downhole tractor - Google Patents

Abstract

The invention belongs to the field of oil and gas development, and in particular relates to a control system for an electronically controlled hydraulically driven coiled tubing downhole tractor. The control system of the coiled tubing downhole tractor driven by electronically controlled hydraulic pressure includes a control system housing, a motor module, a hydraulic pipeline module, and an electronic control module; The pipeline module and the electronic control module; the motor module includes a traction control servo motor and a support control servo motor; the traction control servo motor and the support control servo motor are controlled by instructions sent by the electronic control module. The tractor control system has good flexibility and is suitable for downhole traction control operations in slim holes. During the traction control process, normal downhole fluid circulation can be ensured, effective control of traction speed can be achieved, and effective power-off protection, Two-way traction control can realize effective control of traction speed.

Description

A control system for an electronically controlled hydraulically driven coiled tubing downhole tractor

technical field

The invention belongs to the field of oil and gas development, and in particular relates to a control system for an electronically controlled hydraulically driven coiled tubing downhole tractor.

Background technique

In the late 1990s, many foreign companies successively developed horizontal well traction devices (that is, cable tractors) that can independently operate underground. After years of development, so far, representative tractor products mainly include: Well Tractor wheeled tractor from Denmark Welltec Company, Sondex wheeled tractor from UK Sondex Co., Ltd., PowerTrac from Norway Maritime Well Service (MWS) company Advance wheeled tractors, PowerTrac INVADER crawler tractors, SmarTract telescopic tractors from British ExproGroup, MaxTRAC telescopic tractors from French Schlumberger, and Microhole Drilling Tractor telescopic tractors from Western Well Tool Company in the United States. Among them, the Microhole Drilling Tractor telescopic tractor of Western Well Tool Company of the United States is a coiled tubing-type tractor driven by high-pressure drilling fluid on the ground and can be used in small holes. It can maintain effective drilling fluid circulation during work; most of the other tractors are It is wheeled or crawler-type, with a large peripheral size, and is only suitable for large-diameter wells. It is connected by cables or wire ropes, driven by electricity, and has small traction. It cannot perform effective drilling fluid circulation during work, and is generally limited to applications in the logging industry. .

But no matter what kind of tractor, as far as China is concerned, strict technical secrecy measures have been taken abroad, so that domestic research on downhole tractors is still in its infancy: since August 2002, the Tarim Oilfield has passed technical cooperation. In this way, the downhole tractor technology was used to explore the industrial profile logging of horizontal wells, and achieved certain results. Since then, a few domestic scientific research institutes have also carried out research on downhole tractors, mainly including China University of Petroleum, Harbin Institute of Technology, Southwest Petroleum Institute, Daqing Petroleum Institute, Xi'an Petroleum University, etc., and have also applied for some tractor patents. However, these tractors have more or less disadvantages, and most of them are limited to the use of circulating hydraulic pressure for drive control, and no servo stepping motor is directly used for drive and control of the tractor, which cannot better meet the requirements of underground operations.

Gao Jinwei, Liu Meng and others from China University of Petroleum proposed a structural scheme of a wheeled tractor in the literature (Gao Jinwei, Liu Meng, Yan Xiangzhen. Downhole wheeled adaptive pipeline crawler for horizontal wells: China), and applied for a practical New type patent (200520008070.8.2006-08-16, variable-diameter traction device for casing horizontal well logging tractor); Harbin Institute of Technology also developed a cable wheel tractor (Tang Dewei, Wang Xinjie, Deng Zongquan. Horizontal oil well detection instrument Tractor. Journal of Harbin Institute of Technology. 2007, 39 (9): 1395-1397), and carried out ground test; Design of Traction Crawler for Flat Well Logging Instruments. New Technology and New Technology, 2007, (12): 32-34); Liaohe Petroleum Exploration Bureau proposed a wheeled tractor with independent intellectual property rights (200720190260.5, Cased Horizontal Well Logging tractor variable-diameter traction device), and in 2008, the Great Wall Drilling and Detection Company conducted downhole tests on the tractor developed by it in four horizontal wells in Liaohe Oilfield, and some other scientific research institutes also conducted related aspects of wheeled tractors. research, but these tractors have some things in common: they are all wheeled tractors, they are all connected by cables without circulation, and they are all tractors for downhole operations with little traction such as well logging and workover, so there are many defects. The main defects are as follows: (1) The electric drive control system connected by cables or wire ropes cannot effectively connect the coiled tubing to be driven by surface hydraulic pressure and realize effective drilling fluid circulation and control; (2) Most tractor control systems cannot realize two-way (3) Most tractor control systems cannot realize the protection measures for automatic retraction of the power-off support mechanism; (4) Most tractor control systems are highly resistant to ground pump pressure, and the starting working pressure difference and the maximum working pressure difference cannot achieve effective control.

Shao Shoujun and Chang Yulian of Daqing Petroleum Institute proposed a telescopic actuator with piston-like movement of the gate (Shao Shoujun. Research on Oil Well Fault Detection Robot Based on Virtual Prototype. Master Thesis of Daqing Petroleum Institute. 2007: 5-7) mainly It is composed of electrical components, hydraulic components, upper support and travel components, lower support and travel components and detection components. The four hydraulic cylinders are controlled by electromagnetic reversing valves, so that the upper and lower support and travel components can be alternately tightened or retracted as required. Extend and retract, so as to realize autonomous travel, but this tractor has great defects: (1) The connecting cable is used to supply power to the electrical components to drive the motor to make the hydraulic mechanism work, and there is no drilling fluid circulation channel in the tractor, It is impossible to realize the effective circulation of the downhole liquid and the ground during the operation; (2) The control system uses electromagnetic reversing valves to control the four hydraulic cylinders, which cannot effectively control the traction speed; (3) The traction control system has no overload protection and power failure Automatic safeguard for slip retraction.

Southwest Petroleum University Zhu Xiaohua, Hu Zhiqiang, Shi Changshuai, etc. (201110081197.2, coiled tubing crawler and its crawling method) coiled tubing crawler and its crawling method are composed of front crawling device, controller and rear crawling device, although coiled tubing is used The connection is driven by the ground hydraulic device, but this patent has obvious shortcomings: (1) the traction part adopts two traction hydraulic cylinders for traction drive and control, which makes the traction part too long, and the support mechanism adopts single hydraulic cylinder drive and The spring return device makes the hydraulic pipeline of the tractor complex, and the minimum applicable wellbore diameter is large, which is not suitable for traction in the slim hole; (2) Due to the downhole operation of the coiled tubing, the circulation pressure loss in the coiled tubing is large, and the pure hydraulic drive is used and control, there are certain requirements on the minimum pressure difference inside and outside the tractor. Only when the ground pump pressure reaches a certain value can the tractor be driven to work normally, which makes the tractor more dependent on the ground pressure and the traction control is not flexible; (3) It only proposes the concept of hydraulic drive control, but does not give a specific hydraulic drive and control pipeline implementation plan; (4) Without a speed regulating throttle valve, effective control of the traction speed cannot be realized; (5) Traction control No overload protection and automatic protection measures for power-off slip retraction.

With the increasingly widespread application of downhole tractors, the oil drilling industry has introduced a variety of downhole tractor products from abroad for downhole operations. Although domestic research on tractors started relatively late, it is limited to motor-wheeled downhole tractors and hydraulic drives. Coiled tubing downhole tractors, purely mechanical cam-type downhole tractors and other single-drive researches have not reached the market with mature products, and there are still many defects in the tractor control system, which cannot better meet the requirements of downhole operations. The main reasons are:

(1) Foreign countries have adopted strict technical confidentiality measures for the downhole tractor technology, making the domestic research on the tractor control system completely in the state of independent research and development;

(2) Domestic research on tractors is limited to well logging, and there are few studies on tractors for drilling operations. There are no tractors for downhole traction operations in small holes or small holes in China, so it is difficult to study the control system of downhole tractors in small holes or small holes larger;

(3) Domestic tractors: There are many valves for single hydraulic drive control, the structure is more complex, the stability is poor, there is no control of starting pressure difference, overload pressure difference and automatic retraction protection of power-off support mechanism, and it is dependent on ground input pump pressure larger;

(4) The tractor control system can only realize the control of one-way downward traction into the well, and cannot control the two-way traction;

(5) The control system of the hydraulically driven tractor that has a circulation pipe channel and can effectively circulate the ground and underground fluid is only given a concept, and there is no specific hydraulic drive control scheme, no test prototype, and no mature product;

(6) Most of them focus on the research on the control system of large-diameter borehole tractors. The research on the control system of small boreholes is limited by the small borehole space, so it is difficult to research and implement.

Contents of the invention

In order to overcome the defects of the prior art, the object of the present invention is to provide a control system of an electronically controlled hydraulically driven coiled tubing downhole tractor, which utilizes an electronic control module to control a servo motor so that two five-position five-way reversing valves can precisely control the hydraulic pressure. The circuit, together with the control of other valves, realizes the effective hydraulic drive tractor to pull the coiled tubing string downhole to run in and take it out smoothly, which solves the problems such as the difficulty in running in and out, and the difficulty in applying drilling pressure due to the large friction resistance of the coiled tubing in the downhole. Difficulties, so that the coiled tubing can be extended longer downhole.

In order to achieve the above object, the present invention adopts following scheme:

A control system for an electronically controlled hydraulically driven coiled tubing downhole tractor, including a control system housing, a motor module, a hydraulic pipeline module, and an electronic control module; it is characterized in that the motor modules are sequentially installed in the control system housing from top to bottom , a hydraulic pipeline module, and an electronic control module; the motor module includes a traction control servo motor and a support control servo motor; the traction control servo motor and the support control servo motor are controlled by instructions sent by the electronic control module.

Preferably, the hydraulic pipeline module includes a two-position three-way valve for the upper slip cylinder, an inlet pressure-limiting two-position three-way valve, a four-position five-way valve for the support cylinder, an inlet spring overflow valve, and a three-position five-way valve for the traction cylinder. valve.

Preferably, the three-way interface pipelines of the two-position three-way valve of the upper slip cylinder are as follows: the inlet end is connected to the drilling fluid pressure pipeline, and the other two-way outlet ends are respectively connected to the pressure pipeline of the first upper slip cylinder and the second upper Slip cylinder pressure pipeline; two of them are controlled by spring and solenoid valve.

Preferably, the inlet pressure-limiting two-position three-way valve is a two-position three-way spring electromagnetic hydraulic control valve, and the three-way interface pipelines are: the inlet end is connected to the drilling fluid inlet pressure pipeline, and the two outlet ends are respectively connected to the high-pressure drilling fluid pressure pipeline and Drilling fluid return wellbore annulus pipeline; inlet pressure limiting two-position three-way valve is equipped with an electromagnet at one end and a spring at the other end; the high-pressure hydraulic control inlet at the electromagnet end is connected to the drilling fluid inlet pressure pipeline, and the low-pressure hydraulic control inlet at the spring end Connected to drilling fluid return wellbore annulus pipeline; two of them are controlled by spring, electromagnet magnetic force, pressure difference between drilling fluid inlet pressure pipeline and drilling fluid return wellbore annulus pipeline.

Preferably, the inlet spring overflow valve is a two-position two-way spring electromagnetic overflow valve, one end of the inlet spring overflow valve is equipped with an electromagnet, and the other end is equipped with a spring, and the inlet of the inlet spring overflow valve is connected to the high-pressure drilling fluid pressure pipeline. The outlet end of the imported spring overflow valve is connected to the drilling fluid return wellbore annulus pipeline, the low-pressure hydraulic control inlet at the spring end is connected to the drilling fluid return wellbore annulus pipeline, and the high-pressure hydraulic control inlet at the electromagnet end is connected to the high-pressure drilling fluid pressure pipeline; the imported spring The second position of the relief valve is controlled by the pressure difference between the high-pressure drilling fluid pressure pipeline and the drilling fluid return wellbore annulus pipeline and the spring thrust, so that the high-pressure drilling fluid pressure pipeline is connected or disconnected from the drilling fluid return wellbore annulus pipeline. open.

Preferably, one inlet of the four-position five-way valve of the support cylinder is connected to the high-pressure drilling fluid pressure pipeline, both return outlets are connected to the drilling fluid return wellbore annulus pipeline, and the two outlets are respectively connected to the drilling fluid pressure pipeline and the pressure pipe of the lower slip cylinder The upper end of the spool of the four-position five-way valve of the support hydraulic cylinder is connected to the support control servo motor, and the lower end of the spool is connected to the spring; the four-position five-way valve of the support hydraulic cylinder is divided into four positions from top to bottom: the first position, drilling hydraulic pressure The power pipeline is connected with the drilling fluid return wellbore annulus pipeline, and the high-pressure drilling fluid pressure pipeline is connected with the pressure pipeline of the lower slip cylinder; secondly, the high-pressure drilling fluid pressure pipeline is connected with the drilling fluid pressure pipeline and the lower slip fluid cylinder respectively. The cylinder pressure pipeline is connected, and the drilling fluid return wellbore annulus pipeline is disconnected from the drilling fluid pressure pipeline and the pressure pipeline of the lower slip hydraulic cylinder; the third position is that the high-pressure drilling fluid pressure pipeline is connected with the drilling fluid pressure pipeline, and the lower slip hydraulic pressure pipeline is connected. The pressure line of the tile cylinder is connected with the drilling fluid return wellbore annulus pipeline; the fourth place, the drilling fluid return wellbore annulus line is connected with the drilling fluid pressure line and the lower slip cylinder pressure line at the same time. The hydraulic pressure pipeline is disconnected from the drilling fluid pressure pipeline and the pressure pipeline of the lower slip hydraulic cylinder at the same time; the first, second and third communication methods of the four-position five-way valve of the support hydraulic cylinder are all connected by adjustable flow Method: The position of the spool changes, the size of the flow section of the channel changes, and the flow rate of the liquid flowing through the channel is different. The position of the spool is precisely controlled by the support control servo motor, so as to accurately control the size of the flow section of the upper three-position connection interface, so that the input And the output fluid flow rate is effectively controlled.

Preferably, one inlet of the three-position five-way valve of the traction cylinder is connected to the high-pressure drilling fluid pressure pipeline, the two return outlets are connected to the drilling fluid return wellbore annulus pipeline, and the other two outlets are connected to the traction cylinder pressure pipeline and the traction cylinder pressure line respectively. Pipeline; the upper end of the three-position five-way valve spool of the traction cylinder is connected to the traction control servo motor, and the lower end of the three-position five-way valve spool of the traction cylinder is connected to the spring; the three-position five-way valve of the traction cylinder has three positions from top to bottom : Upper position, the high-pressure drilling fluid pressure pipeline is connected to the traction fluid cylinder pressure pipeline, and the traction fluid cylinder pressure pipeline is connected to the drilling fluid return wellbore annulus pipeline; the middle position, the high-pressure drilling fluid pressure pipeline is connected to the drilling fluid return wellbore annulus The pipeline, the traction cylinder pressure pipeline, and the traction cylinder pressure pipeline are respectively disconnected into an open circuit state; the lower part: the high-pressure drilling fluid pressure pipeline is connected to the traction cylinder pressure pipeline, and the traction cylinder pressure pipeline is connected to the drilling fluid return wellbore The annular pipeline is connected; the upper and lower communication modes of the three-position five-way valve of the traction cylinder adopt adjustable flow communication mode: precisely controlling the position of the spool can control the size of the upper three-position connection interface, so that the input and output fluid flow rates are effectively controlled The upper end of the three-position five-way valve spool of the traction cylinder is connected with a traction control servo motor, which can precisely control the position of the three-position five-way valve spool of the traction cylinder.

Preferably, the traction control servo motor can accurately control the displacement of the spool of the three-position five-way valve of the traction cylinder, and the passage cross-section of the upper and lower spools of the three-position five-way valve of the traction cylinder is adjusted according to the displacement of the spool, and the control The traction control servo motor can precisely control the cross-section size of the upper and lower spool channels of the three-position five-way valve of the traction cylinder, control the flow rate, and control the traction speed; the support control servo motor can accurately control the four-position five-way support cylinder The displacement of the valve spool, the flow cross section of the four-position 5-way valve of the supporting hydraulic cylinder is adjusted with the displacement of the spool, and the traction control servo motor can accurately control the upper and lower positions of the 3-position 5-way valve of the traction cylinder. The cross-section size of the channel of the lower spool controls the size of the flow rate, and controls the opening and contraction speed of the upper and lower slips.

Preferably, the lower end of the four-position five-way valve of the support cylinder is connected to a return spring, and the spool of the four-position five-way valve of the support cylinder moves to the state of the fourth position pressure relief circuit after the power is cut off: the drilling fluid return wellbore annulus pipeline is connected with the drilling fluid at the same time. The hydraulic pressure pipeline is connected with the pressure pipeline of the lower slip cylinder, and the circulating liquid in the upper slip cylinder and the lower slip cylinder is simultaneously returned to the annulus of the low-pressure wellbore through the circulating fluid pipeline, and the upper and lower slips At the same time, it leaves the well wall to prevent the drill from being stuck due to power failure.

Preferably, along the pipe wall, the upper center sliding pipe is respectively processed with the first upper slip cylinder pressure pipeline, the second upper slip cylinder pressure pipeline, the upper traction cylinder pressure pipeline, and the lower traction cylinder pressure pipeline ;The lower outlet of the pressure line of the first upper slip cylinder, the lower outlet of the pressure line of the second upper slip cylinder, the lower outlet of the pressure line of the upper traction cylinder, and the lower outlet of the pressure line of the lower traction cylinder They are all on the lower outer surface of the upper center slide tube, and are respectively connected to the hydraulic pipeline modules; the upper end outlet of the pressure line of the first upper slip cylinder is clamped when the upper support system is at the uppermost end of the upper center slide tube. The upper slip cylinder is within the coverage of the upper center slide pipe, and the upper end outlet of the pressure line of the second upper slip cylinder is at the lower end of the upper center slide pipe when the upper support system is on the upper center slide pipe. within the above coverage; the upper outlets of the pressure pipelines of the upper and lower traction cylinders are respectively on the upper and lower sides of the piston of the traction cylinder; the hydraulic pipeline module controls the disconnection or connection of the pressure pipelines of the first upper slip cylinder and the second The connection or disconnection of the pressure pipeline of the upper slip cylinder, the input or output circulation fluid to the upper slip cylinder; the hydraulic pipeline module controls the pressure pipeline of the traction cylinder to input or output circulation fluid to the upper traction cylinder, the hydraulic pressure The pipeline module controls the pressure pipeline of the traction cylinder to output or input circulating fluid to the lower traction cylinder, and push the piston of the traction cylinder to move downward or upward.

Compared with the prior art, the present invention has the following advantages:

(1) The flexibility of the tractor control system is better: the tractor control system of domestic research mainly focuses on simple heavy hydraulic control or simple electric control, which is highly dependent on hydraulic pressure and the drive control system is more complicated; the tractor control system of the present invention Adopt hydraulic drive control, combined with electronic control module and servo motor integrated control method to reduce the complexity of the pure hydraulic control pipeline. No matter how large the surface pump pressure is, as long as there is a pressure difference between the inside and outside of the downhole tractor and the power is turned on, the traction can be started. At the same time, the inlet and outlet valves adopt three-position five-way reversing valve and four-position five-way reversing valve, which can precisely control the position of the valve core through the servo stepping motor, adjust the size of the inlet and outlet valves, and control the flow to achieve flexibility. For the purpose of controlling the traction speed, the control flexibility is better.

(2) The tractor control system can be applied to downhole traction control operations in small boreholes: many tractor control systems in China are suitable for the tractor control of the connecting rod support structure or the tubular wheel structure with a large borehole diameter, but not for small diameter The control of the wellbore tractor; the support system adopted by the tractor control system of the present invention is an inclined-plane sliding and extrapolating slip expansion structure, and the support part is relatively compact, which effectively reduces the minimum applicable wellbore diameter of the tractor, so that the control system can be applied It is suitable for downhole tractor traction control operation in small boreholes or even small boreholes.

(3) The tractor control system can ensure normal downhole fluid circulation during traction control: most tractor control systems in China are designed for well logging tractors, and cannot guarantee normal drilling fluid or well washing fluid circulation during work; The tractor control system of the invention reserves internal circulation channels, which can effectively ensure fluid circulation during downhole operations.

(4) The tractor control system can realize effective power-off protection: most domestic tractor control systems do not have an automatic protection device when the power is cut off or there is no hydraulic pressure; The through valve releases the pressure of the slip cylinder, so that the support system relies on the spring return device, and the slips can be automatically retracted by the force of the spring in the event of power failure or no pump pressure, reducing the occurrence of complex situations such as drill sticking of the tractor downhole.

(5) The tractor control system can realize two-way traction control: most tractors in China can only realize one-way traction control; the tractor control system of the present invention can smoothly control the tractor traction string to carry out extraction and lowering operations, and the flexibility is good .

Description of drawings

Fig. 1 is a front view schematic diagram of an electronically controlled hydraulically driven coiled tubing downhole tractor;

Fig. 2 is a top view schematic diagram of an electronically controlled hydraulically driven coiled tubing downhole tractor;

Fig. 3a is a schematic diagram of the upper half of the electronically controlled hydraulically driven coiled tubing downhole tractor when the upper slip is opened along A-A section in Fig. 2;

Fig. 3b is a schematic diagram of the upper half of the electronically controlled hydraulically driven coiled tubing downhole tractor when the upper slip is closed along A-A section in Fig. 2;

Fig. 4a is a schematic diagram of the lower half section along A-A in Fig. 2 when the upper slips of the electronically controlled hydraulically driven coiled tubing downhole tractor are opened;

Fig. 4b is a schematic diagram of the lower half section along A-A in Fig. 2 when the upper slips of the electronically controlled hydraulically driven coiled tubing downhole tractor are closed;

Fig. 5a is a schematic diagram of the hydraulic control principle in the initial state when the electronically controlled hydraulically driven coiled tubing downhole tractor is working;

Fig. 5b is a schematic diagram of the hydraulic control principle for the upper slips of the electronically controlled hydraulically driven coiled tubing downhole tractor to close and leave the well wall;

Fig. 5c is a schematic diagram of the hydraulic control principle for the integral downward traction of the upper slips and the traction cylinder of the electronically controlled hydraulically driven coiled tubing downhole tractor;

Fig. 5d is a schematic diagram of the hydraulic control principle for the upper slips of the electronically controlled hydraulically driven coiled tubing downhole tractor to open and grasp the well wall;

Fig. 5e is a schematic diagram of the hydraulic control principle for the electronically controlled hydraulically driven coiled tubing downhole tractor to close the lower slip and leave the well wall;

Fig. 5f is a schematic diagram of the hydraulic control principle for the overall downward movement of the central slide pipe and lower slips of the coiled tubing downhole tractor driven by electronically controlled hydraulic pressure;

Fig. 5g is a schematic diagram of the hydraulic control principle of the electronically controlled hydraulically driven coiled tubing downhole tractor to open the lower slips and grasp the well wall;

Fig. 6a is a schematic diagram of the hydraulic control principle for power failure protection in the initial state when the electric-controlled hydraulically driven coiled tubing downhole tractor is working;

Fig. 6b is a schematic diagram of the hydraulic control principle for electric-controlled hydraulically driven coiled tubing downhole tractor where upper slips close and leave the well wall for power failure protection;

Fig. 6c is a schematic diagram of the hydraulic control principle for the integral downward traction of the upper slips and the traction cylinder of the coiled tubing downhole tractor driven by electronically controlled hydraulic pressure;

Fig. 6d is a schematic diagram of the hydraulic control principle for electric-controlled hydraulically driven coiled tubing downhole tractor to open the upper slips and grasp the power failure protection of the well wall;

Fig. 6e is a schematic diagram of the hydraulic control principle of the electronically controlled hydraulically driven coiled tubing downhole tractor for the lower slips to close and leave the well wall;

Fig. 6f is a schematic diagram of the hydraulic control principle for the electric control hydraulic drive coiled tubing downhole tractor to move the center slide pipe and the lower slips down as a whole for power failure protection;

Fig. 6g is a schematic diagram of the hydraulic control principle for electric-controlled hydraulically driven coiled tubing downhole tractor to open the lower slips and grasp the well wall power failure protection;

In the figure: 1. Upper slip support system, 2. Center slide pipe assembly, 3. Control system, 4. Lower slip support system; 21. Traction cylinder shell, 22a, external thread, 23b, internal thread, 23. Traction fluid cylinder head, 24. Traction fluid cylinder head seal; 31. Control system housing, 32. Motor module, 33. Hydraulic pipeline module, 34. Electronic control module, 35. Seal ring, 36. Circulating fluid filter Device, 37, circulating fluid filter seal, 38a, external thread, 38b, internal thread; 111, upper center slide pipe, 112, traction cylinder pressure pipeline, 113, traction cylinder piston, 114, traction cylinder pressure tube 115. Piston seal of traction cylinder, 116. Piston displacement sensor of traction cylinder, 117. Pressure difference sensor of traction cylinder, 118. Pressure pipeline of first upper slip cylinder, 119. Second upper slip cylinder Pressure pipeline; 121, upper slip support, 122, upper slip support mud scraper, 123a, upper slip fixing pin groove and pin hole, 123b, upper slip fixing pin, 124, upper slip, 125 , upper slip support sleeve; 131, upper slip liquid cylinder cover, 132, upper slip cover seal, 133a, external thread, 133b, internal thread, 134, upper slip return spring seat, 135, upper slip return spring ; 141, upper slip cylinder piston, 142, upper slip cylinder piston displacement sensor, 143, upper slip cylinder piston seal, 144, upper slip cylinder, 145, upper liquid cylinder housing, 146, upper Slip cylinder shell seal, 147, traction cylinder; 321, traction control servo motor, 322, support control servo motor; 331, drilling fluid inlet pressure pipeline, 332, upper slip cylinder two-position three-way valve, 333. Import pressure-limiting two-position three-way valve, 334. Support fluid cylinder four-position five-way valve, 335. Import spring overflow valve, 336. Drilling fluid return wellbore annulus pipeline, 337. Drilling fluid input pressure pipeline, 338 , Three-position five-way valve of traction cylinder, 339, drilling fluid pressure pipeline; 411, lower center slide pipe, 412, lower slip cylinder pressure pipeline, 413a, external thread, 413b, internal thread; 421, lower slip Support, 422, lower slip support mud scraper, 423a, upper slip fixing pin groove and pin hole, 423b, lower slip fixing pin, 424, lower slip, 425, lower slip support sleeve; 431, Lower slip cylinder cover, 432, lower slip cover seal, 433a, external thread, 433b, internal thread, 434, lower slip return spring seat, 435, lower slip return spring; 441, lower slip liquid cylinder piston , 442, lower slip cylinder piston displacement sensor, 443, lower slip cylinder piston seal, 444, lower slip cylinder, 445, lower slip cylinder housing, 446, lower slip cylinder housing seal .

detailed description

As shown in Fig. 1, the electric-controlled hydraulically driven coiled tubing downhole tractor includes an upper slip support and traction system 1, a center slide pipe assembly 2, a control system 3, and a lower slip support system 4. The upper slip support and traction system 1 slides on the upper part of the center slide tube assembly 2 and can slide up and down along the center slide tube assembly 2; the control system 3 and the lower slip support system 4 are fixed on the center slide tube assembly 2 lower part. The main function of the upper slip support and traction system 1 is to grasp the well wall to support the tractor, and generate axial friction to provide reaction force for the traction force of the tractor. The main function of the control system 3 is to control the working state of the downhole tractor by receiving ground signals. The main function of the lower slip support system 4 is to grasp the well wall to support the tractor, and generate axial friction to provide reaction force for the traction force of the tractor.

As shown in Figures 1-2, 3a, 3b, 4a, 4b, the center slide tube assembly 2 includes: an upper center slide tube 111 , a circulating fluid filter 36 , and a lower center slide tube 411 .

As shown in Figures 1-2, 3a and 3b, the upper center slide tube 111 is a long round tube, and the upper center slide tube 111 is respectively processed with a first upper slip cylinder pressure pipeline 118, a second upper slip cylinder Hydraulic cylinder pressure pipeline 119, upper traction cylinder pressure pipeline 112, lower traction cylinder pressure pipeline 114; upper center sliding tube 111 is processed with traction cylinder piston 113 with larger diameter, upper traction cylinder pressure pipeline 112 and the upper outlet of the lower traction cylinder pressure pipeline 114 are respectively located on the upper and lower sides of the traction cylinder piston 113. Two traction cylinder piston seals 115 and one traction cylinder piston displacement sensor 116 are installed on the traction cylinder piston 113. 1. A differential pressure sensor 117 for the traction cylinder; the lower end of the upper center sliding pipe 111 is processed with a sealed connection external thread 38a, and the lower end surface is provided with an annular positioning flange.

As shown in Figures 1, 4a, and 4b, the lower center slide tube 411 is a stepped oblong tube with a small outer diameter at the upper end and a larger outer diameter at the lower end. The upper end surface of the lower center slide tube 411 is provided with an annular positioning flange. An external thread 413a is processed near the upper end of 411, and a lower slip cylinder pressure pipeline 412 is processed in the tube wall of the lower center sliding tube 411.

As shown in Figures 1, 3a, 3b, 4a, 4b, the circulating fluid filter 36 is a cylinder with oblique screen holes; the upper and lower ends of the circulating fluid filter 36 have annular positioning grooves, and the upper end of the circulating fluid filter 36 Through the annular positioning groove and two circulating fluid filter seals 37, it is sealed with the upper center sliding pipe 111, and the lower end of the circulating fluid filter 36 is sealed with the lower central sliding pipe 411 through the annular positioning groove and two circulating fluid filter seals 37 connect. The main function of the circulating fluid filter 36 is to filter out particles with larger diameters in the drilling circulating fluid to prevent blockage of the hydraulic pipeline.

As shown in Figures 3a and 3b, the upper slip support and traction system 1 includes an upper slip support 121, an upper slip 124, an upper slip support sleeve 125, an upper slip cylinder cover 131, and an upper slip reset spring seat. 134, upper slip return spring 135, upper liquid cylinder housing 145, traction liquid cylinder cover 23.

As shown in 2, 3a, and 3b, the upper slip support 121 is a thick-walled short cylinder, and the upper slip support 121 is slipped on the upper center sliding tube 111 through the inner hole of the cylinder, and the upper slip support 121 and An upper slip support mud scraper 122 is installed between the upper center sliding pipes 111; three sets of slip fixing pin slots and pin holes 123a are evenly distributed on the outer circumference of the lower end of the upper slip support 121 .

As shown in Figures 3a and 3b, the upper cylinder housing 145 is slipped on the upper center slide pipe 111 through the through hole in the middle, the inner diameter of the upper part of the upper cylinder housing 145 is small, the inner diameter of the middle part is the smallest, and the inner diameter of the lower part is the largest; the upper liquid cylinder The upper slip cylinder 144 on the upper part and the traction cylinder 147 on the lower part are formed between the housing and the upper center slide pipe; the outer diameter of the upper slip cylinder housing 144 is smaller than that of the traction cylinder housing 21 Large; the upper cylinder housing 145 and the upper center slide pipe 111 are sealed by two upper slip cylinder housing seals 146; three sets of slip fixing pins are evenly distributed along the outer circumference of the upper cylinder housing 145 Slots and pin holes. The upper end of the upper slip cylinder housing 144 is processed with an internal thread 133b; the lower end of the traction cylinder housing 21 is processed with an internal thread 22b.

As shown in Figures 3a and 3b, the upper slip 124 is an elongated axially symmetrical elastic steel sheet with a width in the middle and narrow ends at both ends, with a triangular slope in the middle along the radial direction and parallel pin holes at both ends. The upper ends of the three upper slips 124 are fixed in the three sets of slip fixing pin grooves and the pin holes 123a on the upper slip support 121 through three sets of upper slip fixing pins 123b, and the lower ends of the three upper slips 124 are fixed through three sets of upper slip fixing pins 123b. The slip fixing pin is put on and fixed on the upper cylinder housing 145 .

As shown in Figures 3a and 3b, the upper slip cylinder cover 131 is a thick-walled short cylinder with a through hole in the middle, and the lower end is provided with a sealed external thread 133a. On the cylinder of the core of the upper slip support sleeve 125, two upper slip cover seals 132 are installed between the upper slip liquid cylinder cover 131 and the core cylinder of the upper slip support sleeve 125. The upper end of the upper cylinder housing 145 is screwed to the upper slip cylinder cover 131 .

As shown in Figures 3a and 3b, the core of the upper slip support sleeve 125 is a cylinder, and the upper slip support sleeve 125 slides on the upper center sliding tube 111 through the core cylinder, and the lower end of the upper slip support sleeve 125 is processed with The upper slip cylinder piston 141, the upper slip cylinder piston 141 is placed in the upper slip cylinder 147; the upper part of the cylinder of the upper slip support sleeve 125 is evenly distributed along the outer circumference direction and welded with three long triangular slopes. Square, the triangular inclined surface goes radially outward, and cooperates with the triangular inclined surfaces on the three upper slips 124. An upper slip cylinder piston displacement sensor 142 and four upper slips are installed on the upper slip cylinder piston 141. The tile liquid cylinder piston seal 143. The upper slip cylinder piston 141 can push the upper slip support sleeve 125 to slide axially on the upper center sliding tube 111 under the thrust of the hydraulic cylinder: when sliding upward, the upper slip support sleeve 125 is pushed away by the triangular slope The three upper slips 124 firmly support the well wall.

As shown in Figures 3a and 3b, the upper slip return spring seat 134 is a thin-walled cup-shaped cylinder with a through hole in the middle, the bottom of the cup leans upward against the upper slip cylinder cover 131, and the upper slip return spring 135 is Helical spring, the upper slip return spring 135 sits against the inner air of the upper slip return spring seat 134, the upper end of the upper slip return spring 135 pushes against the upper bottom surface of the upper slip return spring seat 134, and the lower end of the upper slip return spring 135 Standing against the top surface of the upper slip cylinder piston 141, the upper slip return spring 135 and the upper slip return spring seat 134 are slidably fitted on the cylinder of the upper slip support sleeve 125 core. The main function of the upper slip return spring 135 is to provide downward thrust to the upper slip cylinder piston 141 when the pressure of the upper slip cylinder 144 is removed, so that the upper slip support sleeve 125 slides downward, and the upper slip supports The upper triangular inclined surface of the sleeve 125 and the upper triangular inclined surface of the upper slip 124 are loosened to ensure that the upper slip 124 can be automatically retracted when the external thrust is eliminated; During dismantling, the three upper slips 124 can be retracted away from the well wall by virtue of their own elasticity and the pushing effect of the well wall. The main function of the upper slip return spring seat 134 is to limit the locking of the upper slip support sleeve 125 when the upper triangular inclined surface moves upwards beyond the highest point of the triangular inclined surface on the upper slip 124: the lower end of the upper slip return spring seat 134 is the upper slip The upper side of the piston 141 of the shoe cylinder piston 141 moves upwards to the limit position. When the triangular inclined surface on the upper slip support sleeve 125 moves upwards and reaches the highest point of the triangular inclined surface on the upper slip 124, the lower end of the upper slip reset spring seat 134 is just right. Push against the upper side of the upper slip cylinder piston 141, so that the slip cylinder piston 141 and the upper slip support sleeve 125 cannot continue to slide upwards, preventing the upper slips 124 and the upper slip support sleeve 125 from being locked.

As shown in Figures 3a and 3b, the traction cylinder piston 113 on the upper center slide tube 111 is located in the traction cylinder, and divides the traction cylinder 147 into an upper traction cylinder and a lower traction cylinder. The traction fluid cylinder cover 23 is a thick-walled short cylinder with a through hole in the middle. The traction fluid cylinder cover 23 is slipped on the lower part of the upper center sliding pipe 111 through the middle through hole, and the upper end is provided with a sealed external thread 22a. The traction fluid cylinder shell The lower end of the body 21 and the upper end of the traction fluid cylinder cover 23 are connected by threads; the traction fluid cylinder cover 23 and the upper center sliding pipe 111 are sealed by two traction fluid cylinder cover seals 24 .

As shown in Figures 1, 4a, and 4b, the lower slip support system 4 includes: a lower slip support 421, a lower slip 424, a lower slip support sleeve 425, a lower slip cylinder cover 431, and a lower slip return spring Seat 434, lower slip return spring 435, lower slip cylinder housing 445.

As shown in Figures 2, 4a, 4b, and 5, the lower slip support 421 is a cylinder with a through hole in the middle, and the lower slip support 421 slides on the lower center slide tube 411 through the through hole, and the lower slip support A lower slip support mud scraper 422 is installed between 421 and the lower center slide pipe 411; three sets of slip fixing latch slots and latch holes 423a are evenly distributed on the outer surface of the upper end of the lower slip support 421 along the circumference.

As shown in Figures 2, 4a, 4b, and 5, the lower slip cylinder housing 445 is a cylindrical shell with a thick top and a thin bottom with a circular through hole in the middle, and the lower slip cylinder housing 445 slides through the circular through hole. Set on the lower center sliding tube 411, there are two upper slip cylinder housing seals 446 between the lower slip cylinder housing 445 and the lower center sliding tube 411, the lower slip cylinder housing 445 and the lower center sliding tube The middle of the pipe 411 is sealed by two upper slip cylinder shell seals 446; the inner circular surface of the upper end of the lower slip cylinder shell 445 has an internal thread 413b, and the lower slip cylinder shell 445 connects with the lower center through the internal thread 413b. Slide pipe 411 is connected. The upper end surface of the lower slip cylinder housing 445 has an annular sealing groove, and the upper end surface of the lower slip cylinder housing 445 is sealed and connected with the lower end surface of the control system housing 31 through the sealing ring 35 . Three sets of slip fixing pin slots and pin holes are uniformly distributed along the circumference of the lower slip cylinder housing 445 middle and outside.

As shown in Figures 4a, 4b, and 5, the lower slip 424 is an elongated axially symmetrical elastic steel sheet with a width in the middle and narrow ends at both ends. There is a triangular conical slope in the middle along the radial direction and parallel pin holes at both ends. The lower ends of the three lower slips 424 are fixed on the lower slip support 421 evenly distributed in the circumferential direction through three sets of lower slip fixing pins 423b; the upper ends of the three lower slips 424 are respectively fixed on the lower slip cylinder through three sets of lower slip fixing pins The slips of the housing 445 are fixed in the latch groove and the latch hole. The three lower slips 424 can be opened under the action of the lower slip support sleeve 425, and can be closed by their own elasticity and the extrusion force of the well wall after the external force is removed.

As shown in Figures 4a, 4b, 5, and 6, the core of the lower slip support sleeve 425 is a cylinder, and three rectangular blocks with triangular conical slopes are evenly welded on the lower part of the cylinder along the circumferential direction. Radially outward, and cooperate with each triangular conical inclined surface on the three lower slips 424, can do relative sliding under the action of thrust, to open the three lower slips 424; The upper end of the lower slip support sleeve 425 is processed with The lower slip cylinder piston 441, the lower slip cylinder piston 441 is placed in the lower slip cylinder 444; a lower slip cylinder piston displacement sensor 442 and four lower slip cylinder pistons are installed on the lower slip cylinder piston 441 The piston seal 443 of the tile liquid cylinder, the lower slip support sleeve 425 is a cylinder sliding sleeve on the lower center sliding pipe 411 through the core. The lower slip cylinder piston 441 can push the lower slip support sleeve 425 to slide axially on the lower center slide tube 411 under the thrust of the hydraulic cylinder. Slips 424 firmly support the well wall.

As shown in Figures 4a and 4b, the lower slip cylinder cover 431 is a short cylinder with a through hole in the middle, and the lower slip cylinder cover 431 slides on the cylinder at the core of the lower slip support sleeve 425 through the middle through hole. , there are two lower slip cover seals 432 installed between the lower slip liquid cylinder cover 431 and the core cylinder of the lower slip support sleeve 425; the upper end of the lower slip liquid cylinder cover 431 has a sealed external thread 433a; The shoe cylinder cover 431 supports the lower slip cylinder housing 445 .

As shown in Figures 4a and 4b, the lower slip return spring seat 434 is a cup-shaped cylinder with a through hole in the middle. The slip return spring seat 434 slides on the cylinder of the lower slip support sleeve 425 core together. The lower end of the lower slip return spring 435 rests on the lower slip return spring seat 434 , and the upper end of the lower slip return spring 435 leans against the lower bottom surface of the lower slip cylinder piston 441 . The upper end of the lower slip return spring seat 434 is the downward movement limit position of the lower slip cylinder piston 441 on the lower slip support sleeve 425 to ensure the upper triangular slope of the lower slip support sleeve 425 and the upper triangular slope of the lower slip 424 Can reach the maximum opening fixed point, but can not slide over the lock; the lower slip return spring 435 pushes the lower slip support sleeve 425 upward to retract by spring force when the pressure of the lower slip cylinder housing 445 disappears. When sliding upwards, the lower slip support sleeve 425 is retracted, and the external thrust is removed, and the three lower slips 424 can be retracted away from the well wall by virtue of their own elasticity and the pushing effect of the well wall.

As shown in Figures 3a, 3b, 4a, and 4b, the upper end of the lower slip cylinder pressure pipeline 412 is connected to the electronic control module 34, and the lower end is connected to the lower traction cylinder; the lower slip cylinder pressure pipeline 412 is used to The slip cylinder 444 inputs and outputs fluid. The lower end outlet of the first upper slip cylinder pressure pipeline 118, the lower end outlet of the second upper slip cylinder pressure pipeline 119, the lower end outlet of the traction cylinder pressure pipeline 112, and the lower end of the traction cylinder pressure pipeline 114 The outlets are all on the outer surface of the lower end of the upper center sliding pipe 111, and are respectively connected with the hydraulic pipeline modules 33; the hydraulic pipeline modules 33 respectively control the pressure of the first upper slip cylinder 144 according to the position of the upper slip cylinder 144. The pipeline 118 is disconnected or connected, and the second upper slip cylinder pressure pipeline 119 is connected or disconnected to realize the input or output circulating fluid to the upper slip cylinder 144; the hydraulic pipeline module 33 controls the traction cylinder pressure The pipeline 112 inputs or outputs circulating fluid to the upper traction cylinder, while the traction cylinder pressure pipeline 114 outputs or inputs circulating fluid to the lower traction cylinder, pushing the piston 113 of the traction cylinder to move downward or upward.

As shown in FIGS. 4 a and 4 b , the control system 3 includes a control system housing 31 , a motor module 32 , a hydraulic pipeline module 33 , and an electronic control module 34 . The control system housing 31 is a cylinder with an inner cavity, and the lower end surface of the control system housing 31 is provided with an annular sealing groove. The upper end of the control system casing 31 has an internal thread 38b, and the lower end has an internal thread 413b. The upper end of the control system casing 31 is connected to the external thread 38a on the upper center slide pipe 111 through the internal thread 38b, and the lower end of the control system casing 31 is connected through the internal thread 38b. The thread 413b is connected with the external thread 413a on the lower center sliding tube 411 . A motor module 32 , a hydraulic pipeline module 33 , and an electronic control module 34 are sequentially installed in the cavity of the control system housing 31 from top to bottom. The control system housing 31 has two functions: assembling and supporting the motor module 32 , the hydraulic pipeline module 33 , and the electronic control module 34 ; and connecting the upper center slide pipe 111 and the lower center slide pipe 411 . The main function of the hydraulic pipeline module 33 is to provide input and output pipelines such as the upper slip cylinder 144, the lower slip cylinder 444, the traction cylinder pressure pipeline 112 and the traction cylinder pressure pipeline 114 of the traction cylinder 147. Control the hydraulic circuit and control it to realize the normal work of the tractor.

As shown in Figures 4a, 4b, 5, and 6, the motor module 32 includes a traction control servo motor 321 and a support control servo motor 322; the traction control servo motor 321 and the support control servo motor 322 are respectively controlled by instructions sent by the electronic control module 34; The main function of the traction control servo motor 321 is to realize the accurate displacement of the spool of the three-position five-way valve 338 of the traction hydraulic cylinder, and the main function of the support control servo motor 322 is to realize accurate control of the four-position five-way valve 334 of the support hydraulic cylinder. Accurate displacement of the spool.

As shown in Figures 5 and 6, the hydraulic pipeline module 33 includes a two-position three-way valve 332 for the upper slip cylinder, an inlet pressure-limiting two-position three-way valve 333, a four-position five-way valve 334 for the support cylinder, and an inlet spring overflow valve. Valve 335, three-position five-way valve 338 of the traction cylinder.

As shown in Figures 5 and 6, the two-position three-way valve 332 of the upper slip cylinder is mainly used to control the connection or disconnection of the drilling fluid pressure pipeline 339 with the pressure pipeline 118 of the first upper slip cylinder, and the connection with the second Disconnected or connected state of the upper slip cylinder pressure pipeline 119; the three-way interface pipelines are: the inlet end is connected to the drilling fluid pressure pipeline 339, and the outlet ends of the other two connections are respectively connected to the first upper slip cylinder pressure pipeline 118 And the second upper slip cylinder pressure line 119; wherein the two are controlled by springs and electromagnetic valves, and the two motion processes are respectively:

(1) When the electromagnet on the two-position three-way valve 332 is energized, the electromagnet generates magnetic force to overcome the force of the spring, and pushes the valve core to move to the right, and the drilling fluid pressure pipeline 339 communicates with the pressure pipeline 118 of the first upper slip cylinder, Disconnect the pressure pipeline 119 of the second upper slip cylinder, so that the pressure pipeline 119 of the second upper slip cylinder is disconnected;

(2) When the electromagnet on the two-position three-way valve 332 is powered off, the valve core moves to the left by the action of the spring, so that the drilling fluid pressure line 339 communicates with the pressure line 119 of the second upper slip cylinder, and connects with the first upper slip cylinder pressure line 119. The slip cylinder pressure pipeline 118 is disconnected, so that the first upper slip cylinder pressure pipeline 118 is disconnected.

As shown in Figures 5 and 6, the inlet pressure-limiting two-position three-way valve 333 is mainly used to control the disconnection or connection of the high-pressure drilling fluid pressure pipeline 337 and the drilling fluid inlet pressure pipeline 331; the three-way interface pipelines are: inlet port It is connected to the drilling fluid inlet pressure pipeline 331, and the two outlets are respectively connected to the high-pressure drilling fluid pressure pipeline 337 and the drilling fluid return wellbore annulus pipeline 336; The inlet is connected to the drilling fluid return wellbore annulus pipeline 336; two of them are controlled by the spring, electromagnet magnetic force, and the pressure difference between the drilling fluid inlet pressure pipeline 331 and the drilling fluid return wellbore annulus pipeline 336, and the working conditions are as follows:

(1) When the pressure difference between the drilling fluid inlet pressure pipeline 331 and the drilling fluid return wellbore annulus pipeline 336 reaches a predetermined value, the two-position three-way valve 333 is driven by the pressure difference and the magnetic force generated by the electromagnet to overcome the action of the spring Push the spool to move to the right, the drilling fluid inlet pressure pipeline 331 is connected with the high pressure drilling fluid pressure pipeline 337, and the drilling fluid return wellbore annulus pipeline 336 is disconnected from the high pressure drilling fluid pressure pipeline 337;

(2) When the pressure difference between the drilling fluid inlet pressure pipeline 331 and the drilling fluid return wellbore annulus pipeline 336 does not reach the predetermined value, the two-position three-way valve 333 overcomes the pressure difference thrust and the magnetic force of the electromagnet under the action of the spring, Push the spool to move to the left, the drilling fluid inlet pressure pipeline 331 is disconnected from the high pressure drilling fluid pressure pipeline 337, and the drilling fluid inlet pressure pipeline 331 is connected with the drilling fluid return wellbore annulus pipeline 336. The preset value of the pressure difference between the drilling fluid inlet pressure line 331 and the high pressure drilling fluid pressure line 337 can be set by the electronic control module 34 controlling the magnitude of the current input to the electromagnet.

As shown in Figures 5 and 6, the inlet spring relief valve 335 is a two-position two-way spring electromagnetic relief valve, and its main function is to limit the pressure difference between the high-pressure drilling fluid pressure pipeline 337 and the drilling fluid return wellbore annulus pipeline 336. The maximum preset value plays a role of safety protection for the hydraulic pipeline module 33 . The inlet of the imported spring overflow valve 335 is connected to the high-pressure drilling fluid pressure pipeline 337, the outlet of the imported spring overflow valve 335 is connected to the drilling fluid return wellbore annulus pipeline 336, and the hydraulic control inlet at the spring end is connected to the drilling fluid return wellbore annulus pipeline 336, the hydraulic control inlet at the electromagnet end is connected to the high-pressure drilling fluid pressure pipeline 337. The second position of the imported spring overflow valve 335 is controlled by the pressure difference between the high-pressure drilling fluid pressure pipeline 337 and the drilling fluid return wellbore annulus pipeline 336 and the spring thrust, so that the high-pressure drilling fluid pressure pipeline 337 and the drilling fluid return wellbore The annulus pipeline 336 is connected or disconnected, and the working status is as follows:

(1) When the pressure difference between the high-pressure drilling fluid pressure pipeline 337 and the drilling fluid return wellbore annulus pipeline 336 reaches the preset maximum value, the spool moves to the left, and the high-pressure drilling fluid pressure pipeline 337 and the drilling fluid return wellbore annulus pipeline 336 connected, the high-pressure drilling fluid pressure pipeline 337 releases pressure to the drilling fluid return wellbore annulus pipeline 336, and the pressure difference between the high-pressure drilling fluid pressure pipeline 337 and the drilling fluid return wellbore annulus pipeline 336 decreases accordingly until it is lower than the maximum pressure difference default value;

(2) When the pressure difference between the high-pressure drilling fluid pressure pipeline 337 and the drilling fluid return wellbore annulus pipeline 336 decreases until it is lower than the maximum pressure difference preset value, the spool moves to the right, and the high-pressure drilling fluid pressure pipeline 337 and the drilling fluid return The borehole annulus line 336 is disconnected. The maximum preset value of the pressure difference between the high-pressure drilling fluid pressure pipeline 337 and the drilling fluid return wellbore annulus pipeline 336 can be set by the electronic control module 34 controlling the magnitude of the current input to the electromagnet.

As shown in Figures 5 and 6, one inlet of the four-position five-way valve 334 of the support cylinder is connected to the high-pressure drilling fluid pressure pipeline 337, the two return outlets are connected to the drilling fluid return wellbore annulus pipeline 336, and the other two outlets are respectively connected to the drilling hydraulic pressure. Force line 339 and lower slip cylinder pressure line 412. The four-position five-way valve 334 of the support fluid cylinder is divided into four positions from top to bottom: at the first position, the drilling fluid pressure pipeline 339 communicates with the drilling fluid return wellbore annulus pipeline 336, and the high-pressure drilling fluid pressure pipeline 337 communicates with the lower slip fluid pressure pipeline. The cylinder pressure pipeline 412 is connected; in the second position, the high-pressure drilling fluid pressure pipeline 337 is respectively connected with the drilling fluid pressure pipeline 339 and the lower slip cylinder pressure pipeline 412, and the drilling fluid return wellbore annulus pipeline 336 is connected with the drilling hydraulic pressure pipeline 412. The power pipeline 339 is disconnected from the pressure pipeline 412 of the lower slip cylinder; in the third position, the high-pressure drilling fluid pressure pipeline 337 is connected with the drilling fluid pressure pipeline 339, and the pressure pipeline 412 of the lower slip cylinder is connected with the drilling fluid return well The eye annulus pipeline 336 is in communication; at the fourth position, the drilling fluid return wellbore annulus pipeline 336 is connected with the drilling fluid pressure pipeline 339 and the lower slip cylinder pressure pipeline 412 respectively, and the high-pressure drilling fluid pressure pipeline 337 is connected with the The drilling fluid pressure pipeline 339 and the lower slip cylinder pressure pipeline 412 are disconnected. The upper three-position communication mode of the four-position five-way valve 334 of the support cylinder adopts an adjustable flow communication mode: precisely controlling the position of the spool can control the size of the upper three-position communication interface, so that the input and output fluid flow rates are effectively controlled. The upper end of the support cylinder four-position five-way valve 334 spool is connected to the support control servo motor 322, and the lower end of the spool is connected to the spring; the main function of the support control servo motor 322 is to control the position of the support cylinder four-position five-way valve 334 spool , to ensure the precise displacement of the spool on the four positions respectively, the main function of the spring at the bottom of the spool is to automatically push the spool back to the pressure relief state when the power is off.

The main function of the four-position five-way valve 334 of the support cylinder is to control the connection or disconnection of the high-pressure drilling fluid pressure pipeline 337, the drilling fluid pressure pipeline 339 and the lower slip cylinder pressure pipeline 412, and to control the connection or disconnection of the drilling fluid pressure pipeline 339 or The pressure line 412 of the lower slip cylinder inputs high-pressure liquid or stops the input; controls the connection or disconnection of the drilling fluid return wellbore annulus pipeline 336, the high-pressure drilling fluid pressure line 337 and the drilling fluid input drilling fluid pressure line 339; The drilling fluid pressure pipeline 337 and the drilling fluid input drilling fluid pressure pipeline 339 are pressure relieved or disconnected; in the case of power failure, the drilling fluid input drilling fluid pressure pipeline 339 or the lower slip cylinder pressure pipeline 412 can be automatically pressure relieved , so that the upper slip 124 and the lower slip 424 can automatically return to the contracted state, preventing the phenomenon of drill sticking.

As shown in Figures 5 and 6, the functions of the four-position five-way valve 334 of the support cylinder in different four-position situations are as follows:

(1) First place: the drilling fluid return wellbore annulus pipeline 336 is connected with the drilling fluid pressure pipeline 339, and the drilling fluid pressure pipeline 339 is connected with the pressure pipeline 118 of the first upper slip cylinder or the pressure of the second upper slip cylinder. The pipeline 119 is connected, so that the circulating liquid of the upper slip cylinder 144 returns to the annular space of the low-pressure well, and the upper slip return spring 135 pushes the piston 141 of the upper slip cylinder and the upper slip support sleeve 125 to move downward, and the upper slip The support sleeve 125 and the upper slip 124 slide apart on the triangular slope, and the upper slip 124 shrinks away from the well wall under the action of its own elasticity and the push of the well wall; at the same time, the high-pressure drilling fluid pressure pipeline 337 communicates with the lower slip cylinder pressure pipeline 412 , the lower slip cylinder 444 transports high-pressure circulating liquid, the lower slip cylinder piston 441 overcomes the resistance of the lower slip return spring 435 and drives the lower slip support sleeve 425 to push downward, and the lower slip support sleeve 425 rests on the triangular slope Under the action, the lower slip 424 is forced to open, grasp the support and join the wall; the flow rate of the input and output circulating fluid can be precisely controlled by the support control servo motor 322 so that when the lower slip support sleeve 425 moves down, the triangular slope slides and opens the lower slip 424 The speed of firmly supporting the well wall and the speed at which the upper slip 124 shrinks away from the well wall under the action of its own elasticity and pushing against the well wall can be effectively controlled;

(2) The second position: the high-pressure drilling fluid pressure pipeline 337 is connected with the drilling fluid pressure pipeline 339 and the lower slip cylinder pressure pipeline 412 at the same time, and is simultaneously transported to the upper slip cylinder 144 and the lower slip cylinder 444 through the circulation pipeline The high-pressure circulation liquid makes the upper slips 124 and the lower slips 424 open and grasp the well wall at the same time; the input and output circulating fluid flow rate can be precisely controlled by the support control servo motor 322, so that the upper slips 124 and the lower slips 424 simultaneously The speed of opening and grasping to support the well wall can be effectively controlled.

(3) The third place: the high-pressure drilling fluid pressure pipeline 337 communicates with the drilling fluid pressure pipeline 339, and the drilling fluid pressure pipeline 339 passes through the upper slip cylinder two-position three-way valve 332 to the first upper slip cylinder pressure pipeline 118 Or the pressure line 119 of the second upper slip cylinder conveys high-pressure liquid, and pushes the piston 141 of the upper slip cylinder to overcome the resistance of the upper slip return spring 135 to move upward, so that when the upper slip support sleeve 125 moves upward, the triangular slope slides and opens The upper slip 124 firmly supports the well wall. At the same time, the drilling fluid return wellbore annulus pipeline 336 communicates with the lower slip cylinder pressure pipeline 412, so that the circulating liquid in the lower slip cylinder 444 returns to the low-pressure wellbore annulus, and the lower slip return spring 435 pushes the lower slip The hydraulic cylinder piston 441 and the lower slip support sleeve 425 are pushed upwards, the lower slip support sleeve 425 and the lower slip 424 slide apart on the triangular slope, and the lower slip 424 shrinks away from the well wall under the action of its own elasticity and the well wall push. The input and output circulating fluid flow rate can be precisely controlled by the support control servo motor 322, so that when the upper slip support sleeve 125 moves up, the triangular inclined plane slides and opens the upper slip 124 to grasp the speed of supporting the well wall and the lower slip 424 on its own The elasticity and the velocity of shrinkage away from the wellbore wall under the action of wellbore wall pushing can be effectively controlled.

(4) Fourth place: In the case of power failure, the four-position five-way valve 334 of the support cylinder automatically returns to the state of the pressure relief circuit under the action of the spring: the drilling fluid return wellbore annulus pipeline 336 is connected with the drilling fluid pressure pipeline at the same time. 339 communicates with the lower slip cylinder pressure pipeline 412, through the circulating fluid pipeline, the circulating fluid in the upper slip cylinder 144 and the lower clamp fluid cylinder 444 are simultaneously returned to the annulus of the low-pressure wellbore, so that the upper slip 124 and the The lower slips 424 leave the well wall at the same time to prevent special situations such as power failure or drill sticking.

As shown in Figures 5 and 6, one inlet of the three-position five-way valve 338 of the traction cylinder is connected to the high-pressure drilling fluid pressure pipeline 337, the two return outlets are connected to the drilling fluid return wellbore annulus pipeline 336, and the other two outlets are respectively connected to the traction fluid. Cylinder pressure line 112 and traction cylinder pressure line 114. The three-position five-way valve 338 of the traction cylinder is divided into three positions from top to bottom: the upper position, the high-pressure drilling fluid pressure pipeline 337 communicates with the traction cylinder pressure pipeline 114, and the traction cylinder pressure pipeline 112 connects with the drilling fluid return wellbore annulus The pipeline 336 is connected; the middle position, the high-pressure drilling fluid pressure pipeline 337, the drilling fluid return wellbore annulus pipeline 336, the traction cylinder pressure pipeline 114, and the traction cylinder pressure pipeline 112 are respectively disconnected into an open circuit state; the lower position: high-pressure drilling The hydraulic pressure pipeline 337 communicates with the traction cylinder pressure pipeline 112 , and the traction cylinder pressure pipeline 114 communicates with the drilling fluid return wellbore annulus pipeline 336 . The upper and lower communication modes of the three-position five-way valve 338 of the traction cylinder adopt an adjustable flow communication mode: precisely controlling the position of the spool can control the size of the upper three-position communication interface, so that the input and output fluid flow rates can be effectively controlled. The upper end of the three-position five-way valve 338 spool of the traction cylinder is connected to the traction control servo motor 321, and the lower end is connected to the spring. The main function of the traction control servo motor 321 is to control the position of the three-position five-way valve 338 spool of the traction cylinder to ensure that the valve The precise displacement of the core on the four positions respectively.

The main function of the three-position five-way valve 338 of the traction cylinder is to connect the drilling fluid pressure pipeline 337 with the pressure pipeline 112 of the traction cylinder, pressurize the input liquid of the traction cylinder, and at the same time make the drilling fluid return to the borehole annulus pipeline 336 communicates with the traction cylinder pressure pipeline 114 to release the pressure of the output liquid of the traction lower cylinder; or connect the drilling fluid pressure pipeline 337 with the traction cylinder pressure pipeline 114 to pressurize the input liquid of the traction cylinder. At the same time, make the drilling fluid return wellbore annulus pipeline 336 communicate with the traction cylinder pressure pipeline 112 to release the pressure on the output liquid of the traction upper cylinder; or make the drilling fluid pressure pipeline 337 and the drilling fluid return wellbore annulus pipeline 336, The traction cylinder pressure pipeline 112 and the traction cylinder pressure pipeline 114 are respectively disconnected and are in an open circuit state, keeping the position of the traction cylinder piston 113 in the traction cylinder 147 unchanged.

The functions realized by the three-position five-way valve 338 of the traction cylinder in the upper, middle and lower positions are as follows:

(1) Upper position: the high-pressure drilling fluid pressure pipeline 337 communicates with the traction cylinder pressure pipeline 114, and the high-pressure circulating fluid is input to the lower cylinder of the traction cylinder 147, and the pressure increases; at the same time, the traction cylinder pressure pipeline 112 is connected with the drilling cylinder The liquid return wellbore annulus pipeline 336 is connected, so that the circulating fluid of the upper cylinder of the traction cylinder 147 flows back to the annulus of the low-pressure wellbore, the pressure decreases, and the piston 113 of the traction cylinder moves upward under the action of the pressure difference between the upper and lower cylinders of the traction cylinder. The traction upper center sliding pipe 111 moves upward relative to the upper slips 124; however, the input and output circulating fluid flow rates can be precisely controlled by the traction control servo motor 321, so that the upward movement speed of the traction cylinder piston 113 is the same as that of the traction upper center sliding pipe 111. The speed of the upward movement of the upper slip 124 can be effectively controlled.

(2) Median position: the drilling fluid input pressure pipeline 337, the traction fluid cylinder pressure pipeline 112, the traction fluid cylinder pressure pipeline 114, and the drilling fluid return wellbore annulus pipeline 336 are respectively disconnected, so that the traction fluid cylinder piston 113 and the traction fluid cylinder The upper center slide pipe 111 remains stationary relative to the upper slips 124 .

(3) Lower position: the high-pressure drilling fluid pressure pipeline 337 communicates with the traction cylinder pressure pipeline 112, and high-pressure circulating fluid is input to the upper fluid cylinder of the traction cylinder 147, and the pressure rises; at the same time, the traction cylinder pressure pipeline 114 is connected with the drilling cylinder The fluid return wellbore annulus pipeline 336 is connected to make the circulating fluid of the lower cylinder of the traction cylinder 147 return to the low-pressure wellbore annulus, and the piston 113 of the traction cylinder moves downward under the action of the pressure difference between the upper and lower cylinders of the traction, so that the traction The upper center sliding pipe 111 moves downward relative to the upper slips 124, but the input and output circulation fluid flow rate can be precisely controlled by the traction control servo motor 321, so that the speed of the downward movement of the traction cylinder piston 113 and the traction of the upper center sliding pipe The speed that 111 moves downward relative to upper slip 124 can be effectively controlled.

After the electronic control module 34 receives the signal transmitted from the cable from the ground, it converts it into an action command and sends it to the traction control servo motor 321 and the support control servo motor 322 respectively. After the traction control servo motor 321 receives the action command, it precisely controls the moving position of the spool of the three-position five-way valve 338 of the traction cylinder, so as to realize the precise control of the opening and stopping of the traction cylinder, the magnitude of the traction force, the magnitude of the traction speed, and the direction of traction After the support control servo motor 322 receives the action command, it precisely controls the moving position of the spool of the four-position five-way valve 334 of the support cylinder to realize the opening sequence and opening sequence of the upper slip 124 and the lower slip 424. The precise control of the degree, opening speed, and opening force.

As the depth of coiled tubing operations increases, especially in extended-reach wells and horizontal wells, bottom-hole tools can no longer be driven in or out by only relying on the injection system on the ground. The ground drilling pump must be used to provide hydraulic energy for the circulating fluid. And send instructions to the control system 3 through the ground to make the tractor open and work normally, as shown in Figure 5a: the three upper slips 124 of the upper slip support system 1 of the tractor and the three lower slips 124 of the lower slip support system 4 of the tractor. The slips 424 are all opened to grasp the well wall, and the traction fluid cylinder piston 113 moves down to the vicinity of the traction fluid cylinder cover 23 . Taking the state of the retractor in Figure 5a as the starting state of the work, the working process is divided into the following 6 steps as follows:

In the first step, as shown in Figure 5b, after the control system 3 receives the ground signal, it sends an instruction to the electronic control module 34, and the electronic control module 34 converts it into a motor movement instruction, prompting the motor module 32 to control the hydraulic circuit module 33, so that the traction The control servo motor 321 and the support control servo motor 322 run respectively to push the three-position five-way valve 338 of the traction cylinder and the four-position five-way valve 334 of the support cylinder: the three-position five-way valve 338 of the traction cylinder is in the neutral position, and the drilling fluid is input The pressure pipeline 337, the traction cylinder pressure pipeline 112, the traction cylinder pressure pipeline 114, and the drilling fluid return wellbore annulus pipeline 336 are respectively disconnected, so that the traction cylinder piston 113 and the traction upper center sliding pipe 111 are opposite to the upper slips 124 remains in a static state; the four-position five-way valve 334 of the support fluid cylinder is in the first position, the pressure pipeline 118 of the first upper slip cylinder communicates with the drilling fluid return wellbore annulus pipeline 336, and the second upper slip fluid cylinder The cylinder pressure line 119 is closed, the upper slip cylinder 144 releases pressure, and the upper slip cylinder piston 141 moves downward under the action of the upper slip return spring 135, driving the upper slip support sleeve 125 to retract, and the upper slip 124 After losing the expansion force of the upper slip support sleeve 125, it is automatically retracted by the wellbore action and its own elasticity, and the gripping force between the upper slip 124 and the well wall disappears. When the upper slip cylinder piston 141 is reset to the lowest end , the upper slip cylinder piston displacement sensor 142 on the upper slip cylinder piston 141 generates a displacement termination signal and sends it to the control system 3 .

As shown in Figure 6b, when power failure occurs: upper slip cylinder two-position three-way valve 332, inlet pressure limiting two-position three-way valve 333, inlet spring overflow valve 335, traction cylinder three-position five-way valve 338 Keep the original state unchanged; the spool of the four-position five-way valve 334 of the support cylinder automatically moves up to the fourth position under the action of the spring, so that the drilling fluid pressure pipeline 339 and the lower slip cylinder pressure pipeline 412 are simultaneously connected with the drilling fluid. The backflow well limiting annular pipeline 336 is connected, so that the upper slip cylinder 144 remains in its original state under the action of the upper slip return spring 135, and the upper slip 124 maintains the contracted state; the circulation of the lower slip cylinder 444 Under the action of the lower slip return spring 435, the liquid flows back through the drilling fluid return wellbore annulus pipeline 336 to the wellbore annulus. Its own elasticity automatically retracts, so that the lower slip 425 can automatically return to the contracted state after power failure; therefore, after power failure, the upper slip 124 and the lower slip 425 can maintain or automatically return to the contracted state after power failure , to prevent downhole sticking accidents, and effectively realize the automatic protection function of power failure.

The second step, as shown in Figure 5c: after the electronic control module 34 of the control system 3 receives the signal, it sends out an instruction, and the electronic control module 34 converts it into a motor movement instruction, prompting the motor module 32 to control the hydraulic pipeline module 33, so that the support fluid Cylinder four-position five-way valve 334, upper slip cylinder two-position three-way valve 332, inlet pressure limiting two-position three-way valve 333, import spring overflow valve 335, keep the original state unchanged; make the traction control servo motor 321 run Push the three-position five-way valve 338 of the traction cylinder so that the three-position five-way valve 338 of the traction cylinder is in the upper position, and the high-pressure drilling fluid pressure pipeline 337 communicates with the traction cylinder pressure pipeline 114 on the upper center slide pipe 111, and the traction fluid The lower liquid cylinder of cylinder 147 inputs high-pressure circulating liquid, and the pressure rises; at the same time, the pressure pipeline 112 of the traction liquid cylinder on the upper center slide pipe 111 communicates with the drilling fluid return wellbore annulus pipeline 336, and the drilling fluid return wellbore annulus pipeline 336 communicates with the traction upper cylinder, so that the circulating fluid of the upper cylinder of the traction cylinder 147 flows back to the annulus of the low-pressure wellbore, and the pressure decreases. The upper center sliding pipe 111 moves upward relative to the upper slip 124, and the frictional force of the lower slip branch 424 grasping the well wall provides the reaction force of the traction force, pulling the upper slip support system 1 to move downward as a whole; but the input and output circulating fluid flow rates It can be precisely controlled by the traction control servo motor 321, so that the upward movement speed of the traction cylinder piston 113 and the upward movement speed of the traction upper center slide pipe 111 relative to the upper slip 124 can be effectively controlled; The hydraulic cylinder piston displacement sensor 116 and the traction hydraulic cylinder differential pressure sensor 117 generate real-time signals and send them to the electronic control module 34 of the control system 3 .

As shown in Figure 6c, when a power failure occurs: upper slip cylinder two-position three-way valve 332, inlet pressure limiting two-position three-way valve 333, inlet spring overflow valve 335, traction cylinder three-position five-way valve 338 Keep the original state unchanged; the spool of the four-position five-way valve 334 of the support cylinder automatically moves up to the fourth position under the action of the spring, so that the drilling fluid pressure pipeline 339 and the lower slip cylinder pressure pipeline 412 are simultaneously connected with the drilling fluid. The backflow wellbore annulus pipeline 336 is connected, so that the upper slip cylinder 144 remains in the original state under the action of the upper slip return spring 135, and the upper slip 124 maintains the contracted state; the circulation of the lower slip cylinder 444 Under the action of the lower slip return spring 435, the liquid flows back through the drilling fluid return wellbore annulus pipeline 336 to the wellbore annulus. Its own elasticity automatically retracts, so that the lower slip 425 can automatically return to the contracted state after power failure; therefore, after power failure, the upper slip 124 and the lower slip 425 can maintain or automatically return to the contracted state after power failure , to prevent the occurrence of stuck drill accidents, and effectively realize the automatic protection function of power failure.

The third step, as shown in Figure 5d: after the electronic control module 34 of the control system 3 receives the signals of the traction fluid cylinder living base displacement sensor 116 and the traction fluid cylinder differential pressure sensor 117, it sends an instruction and transmits it to the electronic control module 34, and the electronic The control module 34 is converted into a motor movement instruction, prompting the motor module 32 to control the hydraulic pipeline module 33: making the inlet pressure-limiting two-position three-way valve 333 and the inlet spring overflow valve 335 keep the original state unchanged; making the upper slip cylinder The spool of the two-position three-way valve 332 moves to the left, the pressure pipeline 119 of the second upper slip cylinder is closed, and the pressure pipeline 118 of the first upper slip cylinder communicates with 339; the traction control servo motor 321 is operated to push the traction fluid The three-position five-way valve 338 spool of the cylinder moves to the middle position, and closes the traction cylinder pressure pipeline 112 of the upper traction upper cylinder and the traction cylinder pressure pipeline 114 of the traction lower cylinder, so that the traction cylinder piston 113 is in the traction The position in the hydraulic cylinder 147 remains unchanged; at the same time, the support control servo motor 322 is operated to push the spool of the four-position five-way valve 334 of the support hydraulic cylinder to move to the second position, and the high-pressure circulating fluid enters the mouth pressure pipeline 331 through the high-pressure circulating drilling fluid. The drilling fluid pressure pipeline 337, the drilling fluid pressure pipeline 339, and the first upper slip cylinder pressure pipeline 118 are pressed into the upper slip cylinder 144 to push the upper slip cylinder piston 141 to overcome the reaction force of the upper slip return spring 135 Move upwards, driving the upper slip support sleeve 125 to move upwards, so that the upper slips 124 open and grasp the well wall; when the pressure and displacement reach the predetermined value, the upper slip cylinder piston displacement sensor 142 generates a signal and sends it to the control system 3 electronic control module 34.

As shown in Figure 6d, when power failure occurs: upper slip cylinder two-position three-way valve 332, inlet pressure limiting two-position three-way valve 333, inlet spring overflow valve 335, traction cylinder three-position five-way valve 338 Keep the original state unchanged; the spool of the four-position five-way valve 334 of the support cylinder automatically moves up to the fourth position under the action of the spring, so that the drilling fluid pressure pipeline 339 and the lower slip cylinder pressure pipeline 412 are simultaneously connected with the drilling fluid. The backflow wellbore annulus pipeline 336 is connected, so that the circulating fluid in the upper slip cylinder 144 and the lower slip cylinder 444 can flow back through the drilling fluid return well under the action of the upper slip return spring 135 and the lower slip return spring 435 respectively From the eye annulus pipeline 336 to the wellbore annulus, the upper slip 124 and the lower slip 425 lose the expansion force of the upper slip support sleeve 125 and the lower slip support sleeve 425, and rely on the action of the wellbore and its own elasticity to automatically Retraction makes the upper slips 124 and the lower slips 425 in a contracted state when the power is cut off, so as to prevent downhole stuck pipe accidents and effectively realize the automatic protection function for power cuts.

The fourth step, as shown in Figure 5e; after the electronic control module 34 of the control system 3 receives the signal from the piston displacement sensor 142 of the upper slip cylinder, it sends an instruction and transmits it to the electronic control module 34, and the electronic control module 34 is converted into a motor The motion command prompts the motor module 32 to control the hydraulic pipeline module 33, so that the two-position three-way valve 332 of the upper slip hydraulic cylinder, the two-position three-way valve 333 of the inlet pressure limiting, the imported spring overflow valve 335, and the five-position five-way valve of the traction cylinder Pass valve 338 remains unchanged. Make the support control servo motor 322 run and push the spool of the four-position five-way valve 334 of the support cylinder to move up to the third position, so that the high-pressure drilling fluid pressure pipeline 337 communicates with the drilling fluid pressure pipeline 339, and the drilling fluid pressure pipeline 339 passes through the upper slip The two-position three-way valve 332 of the hydraulic cylinder delivers high-pressure liquid to the pressure pipeline 118 of the first upper slip hydraulic cylinder, so that the upper slip hydraulic cylinder 144 remains unchanged, and the upper slip 124 continues to open to maintain the state of grasping the well wall; at the same time , the drilling fluid return wellbore annulus pipeline 336 communicates with the lower slip cylinder pressure pipeline 412, so that the circulating liquid in the lower slip cylinder 444 returns to the low-pressure wellbore annulus, and the lower slip return spring 435 pushes the lower slip fluid The cylinder piston 441 and the lower slip support sleeve 425 are pushed upwards, the lower slip support sleeve 425 and the lower slip 424 are slid to separate on the triangular slope, and the lower slip 424 shrinks away from the well wall under the action of its own elasticity and the push against the well wall. The flow rate of the input and output circulating fluid can be precisely controlled by the support control servo motor 322, so that the speed at which the lower slip 424 shrinks away from the well wall under the action of its own elasticity and the push against the well wall can be effectively controlled. When the lower slip cylinder piston 441 moves up to a predetermined position, the lower slip cylinder piston displacement sensor 442 also generates and sends a predetermined signal to the electronic control module 34 of the control system 3 .

As shown in Figure 6e, when power failure occurs: upper slip cylinder two-position three-way valve 332, inlet pressure limiting two-position three-way valve 333, inlet spring overflow valve 335, traction cylinder three-position five-way valve 338 Keep the original state unchanged; the spool of the four-position five-way valve 334 of the support cylinder automatically moves up to the fourth position under the action of the spring, so that the drilling fluid pressure pipeline 339 and the lower slip cylinder pressure pipeline 412 are simultaneously connected with the drilling fluid. The backflow wellbore annulus pipeline 336 is connected, so that the lower slip cylinder 444 remains in its original state under the action of the lower slip return spring 435, and the lower slip 424 remains in a contracted state; the circulating liquid in the upper slip cylinder 144 Under the action of the upper slip return spring 135, the return flow passes through the drilling fluid return wellbore annulus pipeline 336 to the wellbore annulus. Its own elasticity automatically retracts, so that the upper slip 125 can automatically return to the contracted state after power failure; therefore, after power failure, the upper slip 124 and lower slip 425 can maintain or automatically return to the contracted state after power failure , to prevent downhole sticking accidents, and effectively realize the automatic protection function of power failure.

The fifth step, as shown in Figure 5f: after the electronic control module 34 of the control system 3 receives the signal from the piston displacement sensor 442 of the lower slip cylinder, it sends an instruction and transmits it to the electronic control module 34, and the electronic control module 34 is converted into a motor The motion command prompts the motor module 32 to control the hydraulic pipeline module 33, keeping the original state of the inlet pressure-limiting two-position three-way valve 333, the support cylinder six-position five-way valve 334, and the inlet spring overflow valve 335 unchanged.

Make the traction servo motor 321 run and push the spool of the three-position five-way valve 338 of the traction cylinder to move up to the lower position: the high-pressure drilling fluid pressure pipeline 337 is connected with the pressure pipeline 112 of the traction cylinder, and high pressure is input to the upper cylinder of the traction cylinder 147 Circulate the liquid, and the pressure rises; at the same time, the traction cylinder pressure pipeline 114 communicates with the drilling fluid return wellbore annulus pipeline 336, so that the circulating fluid of the lower cylinder of the traction cylinder 147 returns to the low-pressure wellbore annulus, and the traction cylinder The piston 113 moves downward under the action of the pressure difference between the upper and lower hydraulic cylinders, so that the upper center sliding pipe 111 moves downward relative to the upper slips 124. The sliding tube 111 and the lower center sliding tube assembly 41 move downwards together with the lower slip support system 4 as a whole. When the upper center slide pipe 111 moves downward relative to the upper slips 124 until the outlet at the upper end of 119 enters the upper slip support sleeve 125 to form an open circuit state, the spool of the two-position three-way valve 332 of the upper slip cylinder moves to the right, Make the drilling fluid pressure pipeline 339 communicate with the second upper slip cylinder pressure pipeline 119, and the first upper slip cylinder pressure pipeline 118 is disconnected to be in an open circuit state. But the flow rate of the circulating fluid input and output can be accurately controlled by the traction control servo motor 321, so that the speed of the downward movement of the traction cylinder piston 113 and the downward movement of the traction upper center sliding pipe 111 relative to the upper slips 124 can be effectively control. Simultaneously, the traction cylinder piston displacement sensor 116 and the traction cylinder pressure difference sensor 117 on the traction cylinder piston 113 generate real-time signals and send them to the electronic control system 34 of the control system 3 .

As shown in Figure 6f, when power failure occurs: upper slip cylinder two-position three-way valve 332, inlet pressure limiting two-position three-way valve 333, inlet spring overflow valve 335, traction cylinder three-position five-way valve 338 Keep the original state unchanged; the spool of the four-position five-way valve 334 of the support cylinder automatically moves up to the fourth position under the action of the spring, so that the drilling fluid pressure pipeline 339 and the lower slip cylinder pressure pipeline 412 are simultaneously connected with the drilling fluid. The backflow wellbore annulus pipeline 336 is connected, so that the lower slip cylinder 444 remains in its original state under the action of the lower slip return spring 435, and the lower slip 424 remains in a contracted state; the circulating liquid in the upper slip cylinder 144 Under the action of the upper slip return spring 135, the return flow passes through the drilling fluid return wellbore annulus pipeline 336 to the wellbore annulus. Its own elasticity automatically retracts, so that the upper slip 125 can automatically return to the contracted state after power failure; therefore, after power failure, the upper slip 124 and lower slip 425 can maintain or automatically return to the contracted state after power failure , to prevent downhole sticking accidents, and effectively realize the automatic protection function of power failure.

Step 6, as shown in Figure 5g: after the electronic control module 34 of the control system 3 receives the real-time signals generated by the traction cylinder piston displacement sensor 116 and the traction cylinder pressure difference sensor 117 on the traction cylinder piston 113, it issues an instruction and Pass it to the electronic control module 34, and the electronic control module 34 converts it into a motor movement command, prompting the motor module 32 to control the hydraulic pipeline module 33, maintaining the two-position three-way valve 332 of the upper slip cylinder and the two-position three-way valve 333 of the inlet pressure limiter. , The original state of the imported spring relief valve 335 remains unchanged. Make the traction control servo motor 321 run and push the spool of the three-position five-way valve 338 of the traction cylinder to move to the neutral position: drilling fluid input pressure pipeline 337, traction cylinder pressure pipeline 112, traction cylinder pressure pipeline 114, drilling fluid return The wellbore annulus pipeline 336 is disconnected respectively, so that the traction cylinder piston 113 and the traction upper center sliding pipe 111 remain stationary relative to the upper slips 124 . At the same time, the support control servo motor 322 is operated to push the spool of the four-position five-way valve 334 of the support cylinder to move to the second position: the high-pressure drilling fluid pressure pipeline 337 is connected with the drilling fluid pressure pipeline 339, and the high-pressure drilling fluid enters through the drilling fluid in sequence. Mouth pressure pipeline 331, high-pressure drilling fluid pressure pipeline 337, drilling fluid pressure pipeline 339, second upper slip cylinder pressure pipeline 119, conveying high-pressure circulating fluid to the upper slip cylinder 144, so that the upper slip 124 can keep supporting the well wall The state remains unchanged; the high-pressure drilling fluid pressure pipeline 337 is connected with the lower slip cylinder pressure pipeline 412 at the same time, and the high-pressure drilling fluid passes through the drilling fluid inlet pressure pipeline 331, the high-pressure drilling fluid pressure pipeline 337, and the lower slip cylinder pressure tube in sequence. At the same time, the high-pressure circulating fluid is delivered to the lower slip cylinder 444, so that the pressure of the lower slip cylinder 444 increases, and the lower slip cylinder piston 441 is pushed to overcome the reaction force of the lower slip return spring 435, driving the lower slip support sleeve 425 Move downward to realize the function of pushing the lower slips 424 to open and grasp the well wall, but the input and output circulation fluid flow rate can be precisely controlled by the support control servo motor 322, so that the speed of the lower slips 424 to open and grasp the well wall can be effectively controlled. After the pushing force and displacement of the lower slip cylinder piston 441 reach the predetermined value, the entire tractor returns to the initial state as shown in Figure 5a, the lower slip cylinder piston displacement sensor 442 generates a signal and sends it to the electronic control system of the control system 3 Module 34.

As shown in Figure 6g, when a power failure occurs: upper slip cylinder two-position three-way valve 332, inlet pressure limiting two-position three-way valve 333, inlet spring overflow valve 335, traction cylinder three-position five-way valve 338 Keep the original state unchanged; the spool of the four-position five-way valve 334 of the support cylinder automatically moves up to the fourth position under the action of the spring, so that the drilling fluid pressure pipeline 339 and the lower slip cylinder pressure pipeline 412 are simultaneously connected with the drilling fluid. The backflow wellbore annulus pipeline 336 is connected, so that the circulating fluid in the upper slip cylinder 144 and the lower slip cylinder 444 can flow back through the drilling fluid return well under the action of the upper slip return spring 135 and the lower slip return spring 435 respectively From the eye annulus pipeline 336 to the wellbore annulus, the upper slip 124 and the lower slip 425 lose the expansion force of the upper slip support sleeve 125 and the lower slip support sleeve 425, and rely on the action of the wellbore and its own elasticity to automatically Retraction makes the upper slips 124 and the lower slips 425 in a contracted state when the power is cut off, so as to prevent downhole stuck pipe accidents and effectively realize the automatic protection function for power cuts.

If the above actions are repeated continuously in the order of "one→two→three→four→five→six→one", the tractor will pull and crawl downward in the underground; on the contrary, if press "six→five→four→three→two→ The sequential operation of "one → six" can realize the reverse traction and crawling function of the retractor underground.

Claims (10)

1. A control system of an electronically controlled hydraulic drive coiled tubing downhole tractor, comprising a tractor and a control system, characterized in that: The tractor includes an upper slip support and traction system, a center slide tube assembly, and a lower slip support system. The upper slip support and traction system is slidingly sleeved on the upper part of the center slide tube assembly, and can Sliding up and down; the control system and the lower slip support system are fixed at the lower part of the center slide pipe assembly, the upper slip support and traction system, and the lower slip support system are respectively used to grasp the well wall to support the tractor and generate axial friction To provide reaction force for the traction force of the tractor, the control system is used to receive ground signals and control the working state of the tractor downhole, The center slide tube assembly includes an upper center slide tube, a circulating fluid filter, a lower center slide tube, The upper center slide pipe is a long round pipe, and the upper center slide pipe is respectively processed with the first upper slip cylinder pressure pipeline, the second upper slip cylinder pressure pipeline, and the upper traction cylinder pressure pipeline along the pipe wall. , the lower traction cylinder pressure pipeline; the upper center slide tube is processed with a traction cylinder piston with a larger diameter, and the upper outlets of the upper traction cylinder pressure pipeline and the lower traction cylinder pressure pipeline are respectively located at the pistons of the traction cylinder On the upper and lower sides, two traction cylinder piston seals, one traction cylinder piston displacement sensor, and one traction cylinder pressure difference sensor are installed on the traction cylinder piston; With annular positioning flange; The lower center slide tube is a stepped oblong tube with a small outer diameter at the upper end and a larger outer diameter at the lower end. The upper end surface of the lower center slide tube is provided with an annular positioning flange, and an external thread is processed near the upper end of the lower center slide tube. The lower slip cylinder pressure line is processed inside the slide tube wall; The circulating fluid filter is a cylinder with oblique screen holes, which is used to filter out particles with larger diameters in the drilling circulating fluid to prevent blockage of hydraulic pipelines. The upper and lower ends of the circulating fluid filter have annular positioning grooves. The upper end of the circulating fluid filter is sealed with the upper center sliding pipe through the annular positioning groove and two circulating fluid filter seals, and the lower end of the circulating fluid filter is sealed with the lower central sliding pipe through the annular positioning groove and the two circulating fluid filter seals connect; The upper slip support and traction system includes an upper slip support, an upper slip, an upper slip support sleeve, an upper slip liquid cylinder cover, an upper slip return spring seat, an upper slip return spring, and an upper liquid cylinder shell body, traction fluid cylinder head, The upper slip support is a thick-walled short cylinder, and the upper slip support is slipped on the upper center sliding pipe through the inner hole of the cylinder, and an upper slip is installed between the upper slip support and the upper center sliding pipe. Support mud scraper; three sets of slip fixing pin grooves and pin holes are evenly distributed on the outer circumference of the lower end of the upper slip support; The casing of the upper cylinder is slidingly sleeved on the upper center sliding pipe through the through hole in the middle, the inner diameter of the middle of the casing of the upper casing is the smallest, the inner diameter of the lower part is the largest, and the inner diameter of the upper part is between the inner diameter of the middle and the inner diameter of the lower part; The upper slip cylinder on the upper part and the traction cylinder on the lower part are formed between the body and the upper center slide tube; the outer diameter of the upper slip cylinder shell is smaller than the outer diameter of the traction cylinder shell; and the upper center slide pipe are sealed by two upper slip cylinder shells; three sets of slip fixing pin grooves and pin holes are evenly distributed along the outer circumference of the upper cylinder shell, and the upper slip cylinder shell The upper end of the body is processed with internal threads; the lower end of the traction cylinder shell is processed with internal threads; The upper slips are long, axially symmetrical elastic steel sheets with a width in the middle and narrow ends at both ends. There is a triangular slope in the middle along the radial direction, and parallel pin holes at both ends. The upper ends of the three upper slips pass through three sets of upper slips. The fixing pins are fixed in the three sets of slip fixing pin grooves and pin holes on the upper slip support, and the lower ends of the three upper slips are fixed on the upper cylinder shell through the three sets of upper slip fixing pins; The upper slip cylinder head is a thick-walled short cylinder with a through hole in the middle, and the lower end is provided with a sealed external thread. On the cylinder, two upper slip covers are installed between the upper slip liquid cylinder head and the core cylinder of the upper slip support sleeve to seal, and the upper end of the upper liquid cylinder shell is threadedly connected with the upper slip liquid cylinder head; The core of the upper slip support sleeve is a cylinder, and the upper slip support sleeve slides on the upper center sliding pipe through the core cylinder, and the lower end of the upper slip support sleeve is processed with an upper slip cylinder piston, and the upper slip The piston of the liquid cylinder is placed in the upper slip liquid cylinder; three rectangular blocks with triangular slopes are evenly welded on the upper part of the cylinder of the upper slip support sleeve along the outer circumference direction. The triangular slopes on the upper slips match each other, and an upper slips cylinder piston displacement sensor and four upper slips cylinder piston seals are installed on the upper slips cylinder piston. Push the upper slip support sleeve to slide axially upward on the upper center sliding tube: when sliding upward, the upper slip support sleeve pushes away the three upper slips through the triangular inclined plane and grasps the shaft wall; The upper slip return spring seat is a thin-walled cup-shaped cylinder with a through hole in the middle, and the bottom of the cup leans upward on the upper slip liquid cylinder cover. Leaning against the inner hole of the upper slip return spring seat, the upper end of the upper slip return spring presses against the upper bottom surface of the upper slip return spring seat, and the lower end of the upper slip return spring presses against the top surface of the upper slip cylinder piston, and the upper The slip return spring and the upper slip return spring seat are slid on the cylinder at the core of the upper slip support sleeve, and the upper slip return spring is used to provide the upper slip cylinder with The piston provides a downward thrust, so that the upper slip support sleeve slides downward, and the triangular inclined surface on the upper slip support sleeve and the triangular inclined surface on the upper slip are released, ensuring that the upper slip can be automatically retracted when the external thrust is eliminated; The lower end of the return spring seat of the upper slip is the limit position of the upward movement of the upper side of the piston of the upper slip cylinder. The lower end of the return spring seat pushes against the upper side of the piston of the upper slip cylinder, so that the piston of the upper slip cylinder and the upper slip support sleeve cannot continue to slide upwards, preventing the upper slip and the upper slip support sleeve from being locked; The traction cylinder piston on the upper center slide tube is located in the traction cylinder, and the traction cylinder is divided into an upper traction cylinder and a lower traction cylinder. The traction cylinder cover is a thick-walled short cylinder with a through hole in the middle, and the traction cylinder The cover is slidingly sleeved on the lower part of the upper center slide pipe through the middle through hole, and the upper end is provided with a sealed external thread, and the lower end of the traction cylinder shell and the upper end of the traction cylinder cover are connected by threads; between the traction cylinder cover and the upper center slide pipe Sealed by two traction fluid cylinder heads; The lower slip support system includes: lower slip support, lower slip, lower slip support sleeve, lower slip liquid cylinder cover, lower slip return spring seat, lower slip return spring, lower slip liquid cylinder case, The lower slip support is a short cylinder with a through hole in the middle, the lower slip support is slipped on the lower center slide tube through the through hole, and the lower slip support is installed between the lower slip support and the lower center slide tube Support mud scraper; three sets of slip fixing pin grooves and pin holes are evenly distributed along the circumference of the upper end of the lower slip support; The casing of the lower slip cylinder is a cylindrical casing with a thick top and a thin bottom with a circular through hole in the middle. The casing of the lower slip cylinder slides on the lower center slide pipe through the circular through hole. There are two upper slip cylinder shell seals between the shell and the lower center slide tube, and the lower slip cylinder shell and the lower center slide tube are sealed by two upper slip cylinder shell seals; The inner circular surface of the upper end of the slip cylinder shell has an internal thread, and the lower slip cylinder shell cooperates with the external thread thread provided on the lower center slide pipe through the internal thread, and the upper end surface of the lower slip cylinder shell has an annular seal. The upper end surface of the lower slip cylinder housing is sealed and connected with the lower end surface of the control system housing through a sealing ring, and three sets of slip fixing pin grooves and pin holes are uniformly distributed along the circumference of the lower slip cylinder housing in the middle and outside; The lower slips are long, axially symmetrical elastic steel sheets with a width in the middle and narrow ends at both ends. There is a triangular conical slope in the middle along the radial direction, and parallel pin holes at both ends. The lower ends of the three lower slips pass through three sets of lower slips. The shoe fixing pins are evenly distributed in the circumferential direction and fixed on the lower slip support; the upper ends of the three lower slips are respectively fixed in the slip fixing pin groove and the pin hole of the lower slip cylinder shell through three sets of lower slip fixing pins, and the three The lower slip can be opened under the action of the lower slip support sleeve, and can be closed by its own elasticity and the extrusion force of the well wall after the external force is removed; The core of the lower slip support sleeve is a cylinder, and three long square blocks with triangular conical slopes are welded evenly along the circumferential direction on the lower part of the cylinder. Each triangular conical inclined surface on the shoe cooperates and can slide relative to each other under the action of thrust to open the three lower slips; the upper end of the lower slip support sleeve is processed with a lower slip cylinder piston, and the lower slip liquid cylinder piston is placed In the lower slip cylinder; a lower slip cylinder piston displacement sensor and four lower slip cylinder piston seals are installed on the lower slip cylinder piston, and the lower slip support sleeve passes through the cylindrical sliding sleeve of the core On the lower center slide tube, the piston of the lower slip cylinder can push the lower slip support sleeve to slide axially on the lower center slide tube under the thrust of the hydraulic cylinder. When sliding down, the lower slip support sleeve passes through the triangular cone The three lower slips are opened on the inclined plane to grasp and support the well wall; The lower slip cylinder cover is a short cylinder with a through hole in the middle, and the lower slip cylinder cover slides on the cylinder at the core of the lower slip support sleeve through the middle through hole. Two lower slip covers are installed between the core cylinders of the slip support sleeve to seal; the upper end of the lower slip cylinder cover has a sealed external thread; the lower slip cylinder cover supports the lower slip cylinder shell effect; The lower slip return spring seat is a cup-shaped cylinder with a through hole in the middle, the bottom of the cup is close to the lower slip liquid cylinder cover, and the lower slip return spring sits in the lower slip return spring seat and slides together. On the cylinder of the lower slip support sleeve core, the lower end of the lower slip return spring rests on the lower slip return spring seat, and the upper end of the lower slip return spring abuts against the lower bottom surface of the lower slip cylinder piston, and the lower slip resets The upper end of the spring seat is the limit position of the downward movement of the piston of the lower slip cylinder, ensuring that the triangular conical inclined surface on the lower slip support sleeve and the triangular conical inclined surface on the lower slip can reach the maximum opening fixed point without slipping Over-locking; when the pressure of the lower slip cylinder disappears, the lower slip return spring relies on the spring force to push the lower slip support sleeve upward to retract. When sliding upward, the lower slip support sleeve retracts. When the external thrust is removed, three The lower slip can be retracted away from the well wall by virtue of its own elasticity and the pushing effect of the well wall; The control system includes a control system housing, in which a motor module, a hydraulic pipeline module, and an electronic control module are sequentially installed from top to bottom; the motor module includes a traction control servo motor and a support control servo motor; the traction control servo motor And the support control servo motor is controlled by the electronic control module sending instructions; The upper end of the pressure pipeline of the lower slip cylinder is connected to the electronic control module, and the lower end is connected to the lower traction cylinder; the pressure pipeline of the lower slip cylinder is used to input and output liquid to the lower slip cylinder. The lower outlet of the pressure line of the shoe cylinder, the lower outlet of the pressure line of the second upper slip cylinder, the lower outlet of the pressure line of the upper traction cylinder, and the lower outlet of the pressure line of the lower traction cylinder are all sliding on the upper center. The outer circular surface of the lower end of the pipe is connected to the hydraulic pipeline module; the hydraulic pipeline module controls the disconnection or connection of the pressure pipeline of the first upper slip cylinder and the connection of the pressure pipeline of the second upper slip cylinder according to the position of the upper slip cylinder. The connection or disconnection of the pressure pipeline of the slip cylinder realizes the input or output of circulating fluid to the upper slip cylinder; the hydraulic pipeline module controls the pressure pipeline of the upper traction cylinder to input or output circulating fluid to the upper traction cylinder, At the same time, the pressure pipeline of the lower traction cylinder outputs or inputs circulating fluid to the lower traction cylinder to push the piston of the traction cylinder to move downward or upward. 2. The control system of the electronically controlled hydraulically driven coiled tubing downhole tractor according to claim 1, characterized in that: The hydraulic pipeline module includes a two-position three-way valve for the upper slip cylinder, an imported pressure-limiting two-position three-way valve, a four-position five-way valve for the support cylinder, an imported spring overflow valve, and a three-position five-way valve for the traction cylinder. 3. The control system of the electronically controlled hydraulically driven coiled tubing downhole tractor according to claim 2, characterized in that: The three-way interface pipelines of the two-position three-way valve of the upper slip cylinder are as follows: the inlet end is connected to the drilling fluid pressure line, and the two outlet ends are respectively connected to the pressure line of the first upper slip cylinder and the pressure line of the second upper slip cylinder. pipeline; two of them are controlled by springs and solenoid valves. 4. The control system of the electronically controlled hydraulically driven coiled tubing downhole tractor according to claim 3, characterized in that: The inlet pressure-limiting two-position three-way valve is a two-position three-way spring electromagnetic hydraulic control valve. The three-way interface pipelines are: the inlet end is connected to the drilling fluid inlet pressure pipeline, and the two outlets are respectively connected to the high-pressure drilling fluid pressure pipeline and the drilling fluid return flow. Wellbore annulus pipeline; the inlet pressure limiting two-position three-way valve is equipped with an electromagnet at one end and a spring at the other end; the high-pressure hydraulic control inlet at the electromagnet end is connected to the drilling fluid inlet pressure pipeline, and the low-pressure hydraulic control inlet at the spring end is connected to the drilling fluid Return wellbore annulus pipeline; Two of them are controlled by the spring, the magnetic force of the electromagnet, the pressure difference between the drilling fluid inlet pressure pipeline and the drilling fluid return wellbore annulus pipeline. 5. The control system of electronically controlled hydraulically driven coiled tubing downhole tractor according to claim 4, characterized in that: the imported spring overflow valve is a two-position two-way spring electromagnetic overflow valve, and one end of the imported spring overflow valve is equipped with Electromagnet, the other end is equipped with a spring, the inlet of the imported spring relief valve is connected to the high-pressure drilling fluid pressure pipeline, the outlet of the imported spring relief valve is connected to the drilling fluid return wellbore annulus pipeline, and the low-pressure hydraulic control inlet of the spring end is connected to the drilling fluid The return wellbore annulus pipeline, the high-pressure hydraulic control inlet at the electromagnet end is connected to the high-pressure drilling fluid pressure pipeline; the second position of the imported spring relief valve depends on the pressure difference between the high-pressure drilling fluid pressure pipeline and the drilling fluid return wellbore annulus pipeline and the spring The thrust is used to control the connection or disconnection of the high-pressure drilling fluid pressure pipeline with the drilling fluid return wellbore annulus pipeline. 6. The control system of the electro-hydraulic driven coiled tubing downhole tractor according to claim 5, characterized in that: One inlet of the four-position five-way valve of the support cylinder is connected to the high-pressure drilling fluid pressure pipeline, and the two return outlets are connected to the drilling fluid return wellbore annulus pipeline, and the two outlets are respectively connected to the drilling fluid pressure pipeline and the pressure pipeline of the lower slip cylinder; The upper end of the spool of the four-position five-way valve of the hydraulic cylinder is connected to the supporting control servo motor, and the lower end of the spool is connected to the spring; the four-position five-way valve of the support hydraulic cylinder is divided into four positions from top to bottom: the first position, the drilling fluid pressure pipeline and the The drilling fluid return wellbore annulus pipeline is connected, and the high-pressure drilling fluid pressure pipeline is connected with the pressure pipeline of the lower slip cylinder; secondly, the high-pressure drilling fluid pressure pipeline is connected with the drilling fluid pressure pipeline and the pressure pipe of the lower slip cylinder respectively. The drilling fluid return wellbore annulus pipeline is disconnected from the drilling fluid pressure pipeline and the pressure pipeline of the lower slip cylinder; the third position is that the high-pressure drilling fluid pressure pipeline is connected with the drilling fluid pressure pipeline, and the lower slip cylinder The pressure pipeline is connected with the drilling fluid return wellbore annulus pipeline; the fourth place, the drilling fluid return wellbore annulus pipeline is connected with the drilling fluid pressure pipeline and the lower slip cylinder pressure pipeline respectively, and the high-pressure drilling fluid pressure pipeline At the same time, it is disconnected from the drilling fluid pressure pipeline and the pressure pipeline of the lower slip cylinder; the first, second and third communication modes of the four-position five-way valve of the support hydraulic cylinder adopt the adjustable flow communication mode: the valve The position of the core changes, the size of the flow section of the channel changes, and the flow rate of the liquid flowing through the channel is different. The position of the valve core is precisely controlled by the support control servo motor, thereby accurately controlling the size of the flow section of the upper three-position connection interface, so that the input and output fluid The flow rate is effectively controlled. 7. The control system of the electro-hydraulic driven coiled tubing downhole tractor according to claim 6, characterized in that: One inlet of the three-position five-way valve of the traction cylinder is connected to the high-pressure drilling fluid pressure pipeline, and the two return outlets are connected to the drilling fluid return wellbore annulus pipeline, and the other two outlets are respectively connected to the pressure pipeline of the traction cylinder and the pressure pipeline of the traction cylinder; The upper end of the three-position five-way valve spool of the traction cylinder is connected to the traction control servo motor, and the lower end of the three-position five-way valve spool of the traction cylinder is connected to the spring; the three-position five-way valve of the traction cylinder has three positions from top to bottom: upper position, The high-pressure drilling fluid pressure pipeline is connected with the traction cylinder pressure pipeline, and the traction cylinder pressure pipeline is connected with the drilling fluid return wellbore annulus pipeline; the middle position, the high-pressure drilling fluid pressure pipeline, the drilling fluid return wellbore annulus pipeline, the traction The hydraulic cylinder pressure pipeline and the traction cylinder pressure pipeline are respectively disconnected into an open circuit state; lower position: the high-pressure drilling fluid pressure pipeline is connected with the traction cylinder pressure pipeline, and the traction cylinder pressure pipeline is connected with the drilling fluid return wellbore annulus pipeline Communication; the upper and lower communication modes of the three-position five-way valve of the traction fluid cylinder adopt an adjustable flow communication mode: precisely controlling the position of the spool can control the size of the upper three-position connection interface, so that the input and output fluid flow rates are effectively controlled; the traction fluid The upper end of the three-position five-way valve spool of the cylinder is connected with a traction control servo motor, and the traction control servo motor can accurately control the position of the three-position five-way valve spool of the traction cylinder. 8. The control system of the electro-hydraulic driven coiled tubing downhole tractor according to claim 7, characterized in that: The traction control servo motor can accurately control the displacement of the spool of the three-position five-way valve of the traction cylinder. The motor can precisely control the flow cross-section size of the upper and lower spool channels of the three-position five-way valve of the traction cylinder, control the flow rate, and control the traction speed; the support control servo motor can precisely control the four-position five-way valve core of the support cylinder The displacement of the four-position five-way valve of the supporting hydraulic cylinder is adjusted with the cross-section of the four-position valve core channel with the displacement of the valve core, and the traction control servo motor can accurately control the upper and lower position valve cores of the three-position five-way valve of the traction cylinder The size of the cross-section of the channel controls the flow rate and the opening and contraction speed of the upper and lower slips. 9. The control system of electronically controlled hydraulically driven coiled tubing downhole tractor according to claim 8, characterized in that: the bottom end of the four-position five-way valve of the supporting hydraulic cylinder is connected with a return spring, and the four-position five-way valve of the supporting hydraulic cylinder is turned off after the power is cut off. The spool moves to the fourth pressure relief circuit state: the drilling fluid return wellbore annulus pipeline is connected with the drilling fluid pressure pipeline and the pressure pipeline of the lower slip cylinder at the same time, and the upper slip cylinder and the pressure pipeline of the lower slip cylinder are simultaneously connected through the circulating fluid pipeline. The circulating liquid in the lower stuck cylinder returns to the annulus of the low-pressure wellbore, and the upper and lower slips leave the well wall at the same time to prevent the drill from being stuck due to power failure. 10. The control system of the electro-hydraulic driven coiled tubing downhole tractor according to claim 9, characterized in that: The upper center sliding pipe is processed with the pressure pipeline of the first upper slip cylinder, the pressure pipeline of the second upper slip cylinder, the pressure pipeline of the upper traction cylinder and the pressure pipeline of the lower traction cylinder respectively along the pipe wall; The outlet at the lower end of the pressure line of the upper slip cylinder, the outlet at the lower end of the pressure line of the second upper slip cylinder, the outlet at the lower end of the pressure line of the upper traction cylinder, and the outlet at the lower end of the pressure line of the lower traction cylinder are all on the upper The outer circular surface of the lower end of the center slide tube is connected with the hydraulic pipeline modules respectively; the upper end outlet of the pressure line of the first upper slip cylinder is the upper slip cylinder when the upper support system is at the uppermost end of the upper center slide tube Within the coverage range on the upper center slide pipe, the upper end outlet of the pressure pipeline of the second upper slip cylinder is covered by the upper slip cylinder on the upper center slide pipe when the upper support system is at the lowermost end of the upper center slide pipe Within the range; the upper outlets of the pressure lines of the upper and lower traction cylinders are respectively on the upper and lower sides of the piston of the traction cylinder; The hydraulic pipeline module controls the disconnection or connection of the pressure pipeline of the first upper slip cylinder, the connection or disconnection of the pressure pipeline of the second upper slip cylinder, and the input or output circulation fluid to the upper slip cylinder; The pipeline module controls the pressure pipeline of the upper traction cylinder to input or output circulating fluid to the upper traction cylinder, and the hydraulic pipeline module controls the pressure pipeline of the lower traction cylinder to output or input circulating fluid to the lower traction cylinder to push the piston of the traction cylinder Move down or up.