CN110485945A - A kind of kill-job liquid constant-pressure becomes discharge capacity feed system and method - Google Patents

Abstract

A kind of kill-job liquid constant-pressure of the present invention becomes discharge capacity feed system and method, belongs to oil-gas field downhole operation technical field, a kind of kill-job liquid constant-pressure change discharge capacity feed system provided by the invention, comprising: kill-job liquid storage tank；Pump dispensing device；Kill-job perfusion pipe nipple, overcurrent tubing string；The present invention proposes that a kind of structure simply has and automatically turns on the device that self-braking constant pressure change discharge capacity continuously supplies perfusion workover fluid, pass through the discharge capacity of frequency converter control pump, the groundwater increment under different trip-out speed can be met, overcome the objective problem of the factors bring such as operation field difference in height, density contrast and discharge capacity difference, versatility is good, and the degree of automation is higher.

Description

System and method for supplying well killing fluid with constant pressure and variable displacement

technical field

The invention belongs to the technical field of downhole operations in oil and gas fields, and is applied to the automatic control of workover operations for oil and gas wells, in particular to a system and method for supplying well killing fluid with constant pressure and variable displacement.

Background technique

During the conventional stringing construction of oil and gas wells, the wellhead is usually in an open state under normal pressure. During this process, the liquid level in the wellbore will decrease. In order to prevent accidents such as overflow and blowout, it is necessary to regularly inject workover fluid into the wellbore to maintain the balance of bottomhole pressure.

At present, the construction site generally adopts the way of special personnel on duty to switch valves to control the injection of workover fluid. Especially for gas test wells, it takes about 8-12 hours to set up the drill string. Operators must repeatedly open and close the gate of the large tank to the wellbore. Liquid injection increases the labor intensity of the operator, and sometimes even the phenomenon that the operator forgets to open the gate to fill the wellbore. This method is not only time-consuming and labor-intensive, but also often occurs when the workover fluid injection volume is insufficient or too much, the injection volume cannot be measured, and it is difficult to match the injection volume with the volume of the extraction string, resulting in high and low fluid levels in the wellbore , further increasing the risk of well control, and bringing major hidden dangers to safe production and environmental protection.

In the process of implementing the embodiments of the present invention, the inventors found at least the following defects in the background technology:

Existing automatic liquid filling devices are all based on the diameter data of the lifting oil pipe, and the filling time is generated in the control module to achieve the purpose of automatic liquid filling. It also needs manual counting and computer calculation to complete the purpose of stage liquid filling , can not realize automatic continuous filling.

Contents of the invention

The present invention provides a constant-pressure variable-displacement supply system and method for well-killing fluid, aiming at solving the above-mentioned problems and solving the existing automatic liquid filling device, which generates filling liquid in the control module based on the diameter data of the oil pipe that is lifted up. It takes time to achieve the purpose of automatic filling, but it also needs manual counting and computer calculation to complete the purpose of stage filling, and the problem of automatic continuous filling cannot be realized.

To achieve the above object, the technical scheme adopted in the present invention is as follows:

A constant pressure and variable displacement supply system for well killing fluid, comprising:

Killing fluid storage tank;

pumping device;

Killing fluid injection nipples, killing fluid injection nipples include:

A pressure sensor, the measuring end of the pressure sensor is connected with the liquid at the bottom of the liquid surface to be measured, and the height of the measuring end of the pressure sensor is the height of the liquid at the bottom of the liquid surface;

flow column;

valve device;

A control module, the control module is used to obtain the pressure value of the pressure sensor to control the opening and closing of the valve device;

The valve device is arranged between the front inlet and outlet in the overflow pipe string, the control module and the pressure sensor are arranged on the flow pipe string, and the control module is electrically connected with the valve device and the pressure sensor respectively;

The killing fluid storage tank is connected to one end of the killing fluid injection nipple through a pumping device, and the other end of the killing fluid injection nipple is connected to the end to be injected.

The control module includes:

a preset module, the preset module is used to preset the upper limit value of the pressure sensor;

A monitoring control module, the monitoring module is used to monitor the value of the pressure sensor, when it is detected that the value is less than the upper limit value, the valve device is controlled to open, and when the value is detected to be above the upper limit value, the valve device is controlled to be closed.

The control module also includes:

A flow rate control module, the flow rate control module is used to preset an intermediate value less than the upper limit value, when the monitoring value of the pressure sensor is less than the intermediate value, the control valve device is opened to the maximum, when the monitoring value of the pressure sensor is above the intermediate value When the monitoring value is in the range from the middle value to the upper limit value, gradually reduce the opening degree of the valve device.

There is a pressure transmission short circuit between the pressure sensor and the liquid at the bottom of the liquid level to be measured, and the pressure sensor communicates with the liquid at the bottom of the liquid level to be measured through the pressure transmission short circuit.

The pumping device includes a base, a centrifugal pump, a diaphragm air pressure tank, and a hydraulic sensor installed on the base. The control module also has a water pump control module. One end of the centrifugal pump is connected to the killing fluid storage tank, and the other end is connected to the diaphragm air pressure tank. The liquid inlet of the tank and the liquid outlet of the diaphragm air tank are connected to the liquid inlet of the killing fluid injection nipple; there is a hydraulic sensor on the diaphragm air tank, and the hydraulic sensor is located on the top of the diaphragm air tank, and the motor in the centrifugal pump is a variable frequency motor , the water pump control module is respectively connected with the hydraulic sensor and the variable frequency motor in communication, the water pump control module monitors the pressure of the hydraulic sensor and controls the centrifugal pump to inject water into the diaphragm air pressure tank to maintain the pressure in the killing fluid storage tank;

An overflow valve is installed on the pipeline between the centrifugal pump and the killing fluid storage tank;

An electromagnetic flowmeter is installed on the pipeline between the diaphragm pressure tank and the killing fluid injection nipple.

The valve device is a pneumatic valve, and the pneumatic valve also has an air source, a power supply, and an electromagnetic two-position five-way reversing valve, and the electromagnetic two-position five-way reversing valve, a pressure sensor, and the control module are electrically connected to the power supply , the electromagnetic two-position five-way reversing valve and the pressure sensor are connected in communication with the control module, one end of the electromagnetic two-position five-way reversing valve is connected to the air source, and the other end is connected to the valve device.

The control module also has a digital display controller, and the digital display controller is electrically connected to the control module.

A method for supplying well-killing fluid with constant pressure and variable displacement, which is used in the control module of any of the above-mentioned supply systems for constant pressure and variable displacement of well-killing fluid, including:

Step 1: Preset the upper limit value of the pressure sensor;

Step 2: Monitoring the value of the pressure sensor, when the monitored value is less than the upper limit value, the control valve device is opened, and when the detected value is above the upper limit value, the control valve device is closed.

Said step 2 also includes:

Step 2.1: Preset an intermediate value that is less than the upper limit value. When the monitoring value of the pressure sensor is less than the intermediate value, the control valve device is opened to the maximum. When the monitoring value of the pressure sensor is above the intermediate value, according to the monitoring value. To the interval position of the upper limit, gradually reduce the opening degree of the valve device.

After said step 2, also include:

Step 3: Record the data of fluid volume and time at the valve device, which is data with a life cycle during the tripping process.

The beneficial effect of the present invention is that the present invention proposes a device with simple structure, automatic start and automatic stop, constant pressure and variable displacement, which continuously supplies and injects workover fluid. The perfusion volume can overcome the objective problems caused by factors such as height difference, density difference and displacement difference at the job site. It has good versatility and a high degree of automation.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of a supply system with constant pressure and variable displacement of well killing fluid according to the present invention;

Fig. 2 is a schematic diagram of the three-dimensional structure of the killing fluid injection nipple in the supply system of constant pressure and variable displacement of well killing fluid according to the present invention;

Fig. 3 is a schematic diagram of the overall structure of the pumping device in a supply system with constant pressure and variable displacement of well killing fluid according to the present invention;

Fig. 4 is a schematic diagram of gas-electric connection in an embodiment of a supply system with constant pressure and variable displacement of well killing fluid according to the present invention.

The marks in the figure are: 1. Killing fluid storage tank; 2. Pump injection device; 3. Injection pipeline; 4. Killing fluid injection nipple; 5. Digital display controller; 6. Wellhead liquid injection line; 7. Wellhead Liquid column pressure data source; 8. Wellhead flange liquid level overflow port; 9. Base; 10. Centrifugal pump; 11. Frequency conversion motor; 12. Hydraulic sensor; 13. Diaphragm pressure tank; 14. Overflow valve; 15. Inlet; 16. Electromagnetic flowmeter; 17. Outlet; 18. Pressure transmission short circuit; 19. Pressure sensor; 20. Valve device; 21. Liquid inlet short circuit; 22. Self-locking power button switch; 23. Power indicator light ;24. Control module; 25. Filling indicator light; 26. Electromagnetic two-position five-way reversing valve; 27. Pressure signal line; 28. Explosion-proof box; 29. Power switch; 30. Insurance; 31. Digital display controller ; 32, butterfly valve control air pipe; 33, air source; 34, power supply.

Detailed ways

First of all, it needs to be explained that in each embodiment of the present invention, the terms involved are:

The pump injection device 2 is used to provide a pump injection device with a certain pressure liquid. It can use a common pump in the prior art, and can also use a diaphragm type air pressure tank to supply water with a stable pressure. It is a known technology in the prior art .

The overflow pipe string, which is the main body of the pressure well fluid injection nipple 4 of the present invention, is used to connect between the pipelines for injecting and draining the wellhead to control the flow of water injection in the pipeline. The overflow pipe string can be directly connected to the existing On the water injection system, the utilization of the existing water injection system can be realized and the cost can be saved.

In the following, a supply scheme of constant pressure and variable displacement of well killing fluid provided by the embodiment of the present invention will be described in detail through several specific examples.

Example 1

Please refer to FIG. 1 , which shows a schematic diagram of the overall structure of a supply system with constant pressure and variable displacement of well killing fluid provided by an embodiment of the present invention. The supply system with constant pressure and variable displacement of well killing fluid includes:

Killing fluid storage tank 1;

Pumping device 2;

The killing fluid injection sub-section 4, the killing fluid injection sub-section 4 includes:

Pressure sensor 19, the measuring end of pressure sensor 19 communicates with the liquid at the bottom of the liquid surface to be measured, and the height of pressure sensor 19 measuring end is the liquid height at the bottom of the liquid surface;

flow column;

valve means 20;

A control module, the control module is used to obtain the pressure value of the pressure sensor 19 to control the opening and closing of the valve device 20;

The valve device 20 is arranged between the front inlet and outlet of the overflow pipe string, the control module and the pressure sensor 19 are arranged on the flow pipe string, and the control module is electrically connected to the valve device 20 and the pressure sensor 19 respectively. connect;

The killing fluid storage tank 1 is connected to one end of the killing fluid injection nipple 4 through the pump injection device 2, and the other end of the killing fluid injection nipple 4 is connected to the end to be injected.

In the above embodiments, the killing fluid storage tank 1 is used to store the killing fluid, and the pumping device 2 is used to convert the killing fluid in the killing fluid storage tank 1 into a killing fluid with a certain pressure. The injection nipple 4 controls the injection and stop of the killing fluid with a certain pressure output by the pumping device 2 at the wellhead, and the killing fluid injection nipple 4 controls the injection volume of the killing fluid injected into the wellhead; the killing fluid injection nipple 4. It has a pressure sensor 19, a valve device 20 and a control module 24. The monitoring end of the pressure sensor 19 needs to communicate with a position at the lower end of the liquid level of the wellhead of the injection well to monitor the pressure at this position;

In the previous setting work, a preset pressure value needs to be preset in the control module 24, and the preset pressure value is used as a reference value. If the pressure sensor 19 monitors that the pressure value is smaller than the preset pressure value, the control module 24 The control valve device 20 is opened, and the killing fluid with a certain pressure output by the pump injection device 2 is injected into the wellhead to inject fluid into the wellhead. If the pressure sensor 19 detects that the pressure value is greater than or equal to the preset pressure value, the control module 24 controls the valve device. 20 close, stop injecting liquid to the wellhead, continue the above operations, the height of the liquid level in the wellbore that can control the wellhead is constant.

Example 2

Furthermore, in another embodiment of the supply system of constant pressure and variable displacement of well killing fluid according to the present invention, the control module includes:

a preset module, the preset module is used to preset the upper limit value of the pressure sensor;

A monitoring control module, the monitoring module is used to monitor the value of the pressure sensor, when it is detected that the value is less than the upper limit value, the valve device is controlled to open, and when the value is detected to be above the upper limit value, the valve device is controlled to be closed.

In the above embodiment, the control module 24 has a preset module and a monitoring control module. The preset module allows the user to preset the upper limit value of the pressure sensor, and allows the user to adjust the settings; the monitoring control module continuously monitors the pressure sensor 19, When it is detected that the value is less than the upper limit value, the control valve device is opened, and when the value is detected that the value is above the upper limit value, the control valve device is closed to realize automatic control.

Example 3

Furthermore, in another embodiment of the system for supplying well-killing fluid with constant pressure and variable displacement according to the present invention, the control module further includes:

A flow rate control module, the flow rate control module is used to preset an intermediate value less than the upper limit value, when the monitoring value of the pressure sensor is less than the intermediate value, the control valve device is opened to the maximum, when the monitoring value of the pressure sensor is above the intermediate value When the monitoring value is in the range from the middle value to the upper limit value, gradually reduce the opening degree of the valve device.

In the above embodiment, in order to optimize the injection of the killing fluid injection sub-joint 4, the flow rate control module is used to control the injection of the killing fluid into the well for optimal control, and the injection volume of the killing fluid is increased when the killing fluid in the wellbore is particularly low. When there is a lot of killing fluid in the wellbore, inject the killing fluid slowly.

Example 4

Furthermore, in another embodiment of the present invention, a constant pressure variable displacement supply system for well killing fluid, there is a pressure transmission short circuit 18 between the pressure sensor 19 and the liquid at the bottom of the liquid level to be measured, and the pressure sensor 19 passes the pressure The transmission short 18 is in liquid communication with the bottom of the liquid level to be measured.

In the above embodiment, when the killing fluid injection nipple 4 is located at the bottom of the oil and gas well shaft relative to the wellbore of the oil and gas well, the pressure sensor 19 can be installed at the liquid outlet end of the killing fluid injection nipple 4 to directly measure the liquid outlet end. At this time, the user can complete the measurement of the liquid level in the wellbore according to the height between the pressure sensor 19 and the liquid level at the top of the wellbore.

However, when it is arranged at the liquid outlet end of the killing fluid injection sub-joint 4, the fluid flow rate of the killing fluid injection sub-junction 4 is likely to affect the accuracy of the pressure sensor 19 measurement when injecting liquid. Therefore, the pressure sensor 19 and the liquid at the bottom of the liquid level to be measured are provided with a pressure transmission short connection 18, which is used to connect the static liquid at the bottom of the liquid level to be measured with the pressure sensor 19, so that the pressure sensor 19 is not affected by the fluid. The influence of flow velocity, and then accurately measure the liquid level height in the wellbore of oil and gas wells.

Example 5

Further, please refer to FIG. 3 , which is another embodiment of a constant-pressure variable-displacement supply system for well killing fluid in the present invention. The pumping device 2 includes a base 9 , a centrifugal pump 10 installed on the base 9 , and a diaphragm The air pressure tank 13 and the hydraulic pressure sensor 12. The control module also has a water pump control module. One end of the centrifugal pump 10 is connected to the kill fluid storage tank 1, and the other end is connected to the liquid inlet of the diaphragm air pressure tank 13. The liquid outlet of the diaphragm air pressure tank 13 The mouth is connected to the liquid inlet of the killing fluid injection nipple 4; the diaphragm air pressure tank 13 has a hydraulic pressure sensor 12, and the hydraulic pressure sensor 12 is located on the top of the diaphragm air pressure tank 13. The motor in the centrifugal pump 10 is a variable frequency motor 11, and the pump control modules are respectively Communication with the hydraulic sensor 12 and the frequency conversion motor 11, the water pump control module maintains the pressure in the killing fluid storage tank by monitoring the pressure of the hydraulic sensor 12 and controlling the centrifugal pump to inject water into the diaphragm air pressure tank.

In the above embodiment, the main function of the pumping device 2 is to provide a water source with stable pressure to inject the nipple 4 with the killing fluid. In this embodiment, the pumping device 2 adopts an integrated device, the centrifugal pump 10, the diaphragm pressure tank 13 and the hydraulic pressure sensor 12 are all installed on the base 9, when used in the field, no assembly is required when used in the field, which is convenient for users to use.

The pumping device 2 adopts a diaphragm air tank 13, which is an energy storage device composed of a steel shell and a rubber diaphragm liner. The rubber diaphragm completely separates the water chamber from the air chamber. The air in the tank is compressed when the liner of the air pressure water tank is used, and the killing fluid is converted into water injection with constant pressure to supply the killing fluid injection nipple 4 by air compression.

The motor in the centrifugal pump 10 is a variable frequency motor 11. The water pump control module measures the pressure of the air above the diaphragm air tank 13 through the hydraulic sensor 12 to monitor the water storage in the diaphragm air tank 13. When the pressure of the air in the diaphragm air tank 13 is less than When the value is predetermined, the water pump control module controls the centrifugal pump 10 to inject water into the diaphragm air pressure tank 13. In the prior art, there is a mature control module circuit of the diaphragm air pressure tank 13, which will not be described in detail here.

Example 6

Further, please refer to FIG. 3 , which is another embodiment of a supply system for constant pressure and variable displacement of well killing fluid according to the present invention. An overflow valve 14 is provided on the pipeline between the centrifugal pump 10 and the well killing fluid storage tank 1 ;

An electromagnetic flowmeter 16 is arranged on the pipeline between the diaphragm pressure tank 13 and the killing fluid injection nipple 4 .

In the above embodiment, the overflow valve 14 prevents the water in the diaphragm air pressure tank 13 from being overfilled, causing the pressure of the water source provided in the diaphragm air pressure tank 13 to fill the nipple 4 with the killing fluid to be too high, or to inject the nipple 4 with the killing fluid. Too much water inside will cause safety accidents.

Example 7

Further, please refer to Fig. 2 and Fig. 4, another embodiment of a supply system of constant pressure and variable displacement of well killing fluid according to the present invention, the valve device 20 is a pneumatic valve, and the pneumatic valve also has a gas source, Power supply 34, and electromagnetic two-position five-way reversing valve 26, electromagnetic two-position five-way reversing valve 26, pressure sensor 19 and described control module are electrically connected with power supply 34, electromagnetic two-position five-way reversing valve 26 and pressure sensor 19 communicates with the control module, one end of the electromagnetic two-position five-way reversing valve 26 is connected to the air source, and the other end is connected to the valve device 20 .

In the above embodiments, the gas source is conveniently supplied at the oil and gas well site, so the valve device 20 adopts a pneumatic valve, and the control module controls the opening and closing of the pneumatic valve by controlling the electromagnetic 2-position 5-way reversing valve 26 .

Example 8

Furthermore, in another embodiment of the system for supplying constant pressure and variable displacement of well killing fluid according to the present invention, the control module also has a digital display controller, and the digital display controller is electrically connected to the control module.

In the above-mentioned embodiment, the digital display controller specifically adopts the multifunctional controller instrument whose brand is Redlion Red Lion in the United States and whose model is PAXD0010, and other control instruments of the PAXD series of Red Lion can also be used. When in use, it can have two alarms output.

Example 9

An embodiment of the present invention provides a method for supplying well killing fluid with constant pressure and variable displacement, which is used in the control module in any one of Embodiments 1 to 8. The method for supplying well killing fluid with constant pressure and variable displacement includes: :

Step 1: Preset the upper limit value of the pressure sensor;

Step 2: Monitoring the value of the pressure sensor, when the monitored value is less than the upper limit value, the control valve device is opened, and when the detected value is above the upper limit value, the control valve device is closed.

In the above-mentioned embodiments, the upper limit value of the preset pressure sensor is to control the height of the liquid level in the wellbore of the oil and gas well. The liquid level height is when the wellbore fluid is at the highest level, and the pressure sensor 19 is also fixed at the bottom of the wellbore. , the upper limit pressure value of the pressure sensor 19.

Therefore, when the pressure measured by the pressure sensor 19 is lower than the upper limit pressure value, the control module controls the valve device to open, and injects well killing fluid into the wellbore of the oil and gas well; when the pressure measured by the pressure sensor 19 is above the upper limit pressure value, the control module control, the valve device in the killing fluid injection sub-joint 4 is closed.

Example 10

Furthermore, in another embodiment of the method for supplying well killing fluid with constant pressure and variable displacement according to the present invention, the step 2 also includes:

Step 2.1: Preset an intermediate value that is less than the upper limit value. When the monitoring value of the pressure sensor is less than the intermediate value, the control valve device is opened to the maximum. When the monitoring value of the pressure sensor is above the intermediate value, according to the monitoring value. To the interval position of the upper limit, gradually reduce the opening degree of the valve device.

In the above embodiment, when the control module controls the killing fluid injection sub-joint 4, it is also possible to inject the killing fluid in stages. When the killing fluid in the wellbore bottoms out, inject the killing fluid quickly and inject The killing fluid injected into the sub-section 4 is at the maximum flow rate. When the killing fluid in the wellbore is near the preset height of the wellbore, the control module reduces the injection rate of the killing fluid into the sub-section 4.

Example 11

Furthermore, another embodiment of the method for supplying well killing fluid with constant pressure and variable displacement according to the present invention, after the step 2, further includes:

Step 3: Record the data of fluid volume and time at the valve device, which is data with a life cycle during the tripping process.

In the above-mentioned embodiment, during the drilling process, or after the drilling is completed, the change curve of the filling fluid and time is generated, and the filling volume of the entire system is summarized. When the user checks the filling volume, he can check the filling volume , some well problems can be known from this injection rate.

Example 12

The described killing fluid constant pressure variable displacement supply system consists of a killing fluid storage tank 1, a pump injection device 2, a tank filling pipeline 3, an overflow pipe string, a digital display controller 5, and a wellhead fluid column pressure data source 7. Wellhead flange liquid level overflow port 8, wellhead liquid injection line 6;

The inlet of the pump injection device 2 is connected to the wellhead liquid column pressure data source 7 through the tank injection pipeline 3, the outlet of the pump injection device 2 is connected to the inlet of the overflow pipe string through the tank injection pipeline 3, and the outlet of the overflow pipe string passes through the wellhead The liquid injection line 6 is connected to the wellhead liquid column pressure data source 7;

The described supply system of constant pressure and variable displacement of well killing fluid consists of a pump injection device 2, a base 9, a centrifugal pump 10, a frequency conversion motor 11, an inlet 15, a hydraulic pressure sensor 12, a diaphragm pressure tank 13, an overflow valve 14, an electromagnetic flow meter 16, composed of outlet 17;

The overflow pipe string is provided with a pressure transmission short 18 , a pressure sensor 19 , a valve device 20 , and a liquid inlet short 21 .

Self-locking power button switch 22, power indicator light 23, control module 24, filling indicator light 25, electromagnetic two-position five-way reversing valve 26, pressure signal line 27, explosion-proof box body 28, power switch 29, insurance 30, digital Panel instrument 31, pressure sensor 19, valve device 20, digital display controller 31, butterfly valve control air pipe 32, air source 33, power supply 34.

Please refer to Fig. 4, Fig. 4 is the system structural diagram that is used as main control module by digital display controller 31 and control module 24, the pressure information of pressure sensor 19 is displayed on digital display controller 31, and the signal of pressure sensor 19 is transmitted to The control module 24, the electromagnetic two-position five-way reversing valve 26 is controlled by the control module 24, the air inlet of the electromagnetic two-position five-way reversing valve 26 is connected to the air source 33, and the air outlet of the electromagnetic two-position five-way reversing valve 26 It is connected with the killing fluid injection nipple 4, and the control module 24 controls the gas source 33 to the valve device 20 by controlling the position of the reversing valve in the electromagnetic two-position five-way reversing valve 26, and then controls the valve device 20. On or off state.

In Fig. 4, the power supply 34 supplies power to the digital display controller 31, the control module 24 and each electrical device. On the power supply circuit, a power indicator light 23, a power switch 29, a self-locking power button switch 22 and a power supply button switch 22 are installed. Insurance 30, the perfusion indicator light 25 is located on the electromagnetic two-position five-way reversing valve 26, when the electromagnetic two-position five-way reversing valve 26 controls the valve device 20 to open, the perfusion indicator light 25 is bright.

To sum up, the constant pressure and variable displacement supply system for well killing fluid described in the present invention has a light and compact structure, is easy to install and disassemble, and has the functions of automatic start, stop and flow metering, which makes up for the inability to automatically fill liquid at the oil and gas testing site. Blanks where infusion volumes cannot be accurately recorded.

The driller control device of the constant pressure and variable displacement supply system for well killing fluid fully utilizes the power supply and gas source of the workover rig, and the driller selects the fluid injection mode according to the wellbore fluid injection situation, which is safe, reliable, and easy to operate.

The above-mentioned supply system of constant pressure and variable displacement of wellbore killing fluid automatically fills liquid according to the design liquid level, always keeps the wellbore injection volume consistent with the volume of the pipe string to be pulled out, maintains the pressure balance of the wellbore fluid column, and further reduces the pressure in the operation process. well control risk.

The described constant-pressure variable-displacement supply system of well-killing fluid relies on the injection pressure to automatically adjust the displacement and automatically start and stop the injection action, and overcomes the objective problems caused by factors such as height difference, density difference and displacement difference at the operation site, and is universal Good performance, high degree of automation, and good promotion and application value.

It should be noted that all directional indications (such as up, down, left, right, front, back...) in this embodiment are only used to explain the relative relationship between the components in a certain posture (as shown in the accompanying drawings). When the positional relationship, movement conditions, etc., if the specific posture changes, the directional indication will also change accordingly.

In addition, descriptions involving "first", "second" and so on are used for descriptive purposes only, and cannot be understood as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features.

The technical solutions of the various embodiments can be combined with each other, but it must be based on the realization of those skilled in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exist. Not within the scope of protection required by the present invention.

Claims (10)

1. a kind of kill-job liquid constant-pressure becomes discharge capacity feed system characterized by comprising

Kill-job liquid storage tank (1)；

It pumps dispensing device (2)；

Kill-job perfusion pipe nipple (4), kill-job perfusion pipe nipple (4) include:

Pressure sensor (19), the measurement end of pressure sensor (19) and the fluid connection of liquid level to be measured bottom, pressure sensor (19) height of measurement end is to survey liquid level bottom liquid height；

Overcurrent tubing string；

Valving (20)；

Control module, the control module are used to obtain the unlatching of the pressure value control valve device (20) of pressure sensor (19) With closure；

Valving (20) is located between the preceding inlet and outlet in the overcurrent tubing string, the control module and pressure sensor (19) It is located on the overcurrent tubing string, the control module is electrically connected with valving (20) and pressure sensor (19) respectively；

Kill-job liquid storage tank (1) is connect by pumping dispensing device (2) with kill-job perfusion pipe nipple (4) one end, kill-job perfusion pipe nipple (4) The other end is connected to end to be implanted.

2. a kind of kill-job liquid constant-pressure becomes discharge capacity feed system as described in claim 1, which is characterized in that the control module packet It includes:

Presetting module, the presetting module are used for the upper limit value of preset pressure sensor；

Control module is monitored, the monitoring modular is used to monitor the value of pressure sensor, when monitoring that described value is less than upper limit value When, control valve device is opened, and valving is controlled when monitoring that described value is more than upper limit value and is closed.

3. a kind of kill-job liquid constant-pressure becomes discharge capacity feed system as claimed in claim 2, which is characterized in that the control module is also wrapped It includes:

Flow control module, the flow control module are used to preset the median for being less than upper limit value, work as pressure sensor Monitor value be less than median when, control valve device open to maximum, when the monitor value of pressure sensor is more than median When, according to monitor value in the section position of median to upper limit value, gradually decrease the open degree of valving.

4. a kind of kill-job liquid constant-pressure becomes discharge capacity feed system as described in claim 1, which is characterized in that the pressure sensor (19) between the bottom liquid of liquid level to be measured have pressure pass be shorted (18), pressure sensor (19) by pressure pass be shorted (18) with The bottom liquid of liquid level to be measured is connected to.

5. a kind of kill-job liquid constant-pressure becomes discharge capacity feed system as described in claim 1, which is characterized in that the pump dispensing device (2) Including pedestal (9), and the centrifugal pump (10), diaphragm air pressure tank (13) and the hydrostatic sensor (12) that are mounted on pedestal (9), institute Stating also has water pump control modules in control module, centrifugal pump (10) one end connects kill-job liquid storage tank (1), and the other end connects diaphragm The liquid outlet of the inlet of air pressure tank (13), diaphragm air pressure tank (13) is connect with the inlet of kill-job perfusion pipe nipple (4)；Diaphragm There are hydrostatic sensor (12) on air pressure tank (13), hydrostatic sensor (12) is located at the top of diaphragm air pressure tank (13), centrifugal pump (10) motor in is variable-frequency motor (11), and water pump control modules are communicated with hydrostatic sensor (12) and variable-frequency motor (11) respectively Connection, water pump control modules pass through the pressure of monitoring hydrostatic sensor (12) and are infused by controlling centrifugal pump into diaphragm air pressure tank Water maintains the pressure in kill-job liquid storage tank；

Pipeline between centrifugal pump (10) and kill-job liquid storage tank (1) is equipped with overflow valve (14)；

Electromagnetic flowmeter (16) are provided on pipeline between diaphragm air pressure tank (13) and kill-job perfusion pipe nipple (4).

6. a kind of kill-job liquid constant-pressure change discharge capacity feed system as described in claim 1 or 5, which is characterized in that the valving (20) it is operated pneumatic valve, also there is gas source, power supply (34) and electromagnetism switch valve with two-position and five-pass (26), electricity outside the operated pneumatic valve Magnetic switch valve with two-position and five-pass (26), pressure sensor (19) and the control module are electrically connected with power supply (34), and electromagnetism two five Logical reversal valve (26) and pressure sensor (19) and the control module communication connection, electromagnetism switch valve with two-position and five-pass (26) one end It is connect with gas source, the other end is connect with valving (20).

7. a kind of kill-job liquid constant-pressure becomes discharge capacity feed system as claimed in claim 6, which is characterized in that outside the control module also With digital display controller, the digital display controller is electrically connected with the control module.

8. a kind of kill-job liquid constant-pressure becomes discharge capacity supply method, which is characterized in that a kind of for any one described in claim 1-7 Kill-job liquid constant-pressure becomes the control module in discharge capacity feed system, comprising:

Step 1: the upper limit value of preset pressure sensor；

Step 2: monitoring the value of pressure sensor, when monitoring that described value is less than upper limit value, control valve device is opened, and works as prison Valving is controlled when measuring described value more than upper limit value to close.

9. a kind of kill-job liquid constant-pressure becomes discharge capacity supply method as claimed in claim 8, which is characterized in that also wrapped in the step 2 It includes:

Step 2.1: default one is less than the median of upper limit value, when the monitor value of pressure sensor is less than median, control Valving is opened to maximum, when the monitor value of pressure sensor is more than median, according to monitor value in median to upper The section position of limit value, gradually decreases the open degree of valving.

10. a kind of kill-job liquid constant-pressure becomes discharge capacity supply method as described in claim 8 or 9, which is characterized in that the step 2 it Afterwards further include:

Step 3: the data of liquid measure and time at record valving, the data are the number in trip-out process with life cycle According to.