CN102889077B - Testing device for detecting pressure distribution in hole by simulating hydra-jet fracturing under actual working conditions - Google Patents

Abstract

The invention relates to an experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions, which comprises: a support pipe body, a test piece with a through hole in the axial direction, and the test piece is fixed on the support pipe In the body, one end of the test piece is closed, and the other end is provided with a spray plate, and the through hole provided on the spray plate corresponds to the through hole of the test piece; a liquid inlet pipe extends into the support pipe body, Its front end is provided with a nozzle, and the nozzle corresponds to the through hole on the injection plate; the outside of the test piece is arranged along the axial direction with a plurality of pressure measuring joints that can be connected to the pressure measuring device, and the pressure measuring joints It communicates with the through hole to detect the change of the axial pressure in the through hole. The device of the invention can detect the change of the pressure in the simulated perforation hole with the axial position, provide reliable experimental data for the research on the mechanism of hydraulic jet fracturing, and provide theoretical and experimental basis for the design of on-site construction technology.

Description

Experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under simulated actual working conditions

technical field

The present invention relates to an experimental device, in particular to an experimental device for detecting and simulating the pressure distribution in a hydraulic jet fracturing hole. Through the experimental device, the pressure distribution in the formation hole during high-speed jet injection can be truly simulated, and a reliable Experimental data.

Background technique

In 1947, the hydraulic fracturing stimulation technology was first implemented in a vertical well in the HUGOTON gas field in the southwest of KANSAS in the United States. After nearly half a century of development, especially since the late 1980s, in fracturing design, fracturing fluid And additives, proppants, fracturing equipment and monitoring instruments, and fracture monitoring have all achieved rapid development, making hydraulic fracturing technology widely used in fracture height control technology, high-permeability sand control fracturing, repeated fracturing, and deep penetration fracturing. There have been new breakthroughs in fracturing and large-sand-volume multi-stage fracturing. Now hydraulic fracturing technology has been widely used in the development of low permeability oil and gas fields as the main measure to increase production and injection of oil and water wells.

In recent years, although experts and scholars at home and abroad have made great progress in fracturing fluid, proppant, fracturing technology, etc., the basic technology of hydraulic fracturing has not undergone fundamental changes, that is: the surface is generally pressurized, and the underground formation is pressurized. Cracks are formed, and the position and direction of crack initiation are difficult to control. Especially when fracturing open-hole horizontal wells, the large exposed area of the borehole wall will cause a large amount of fracturing fluid leakage, which is even more serious when there are natural fractures downhole; at the same time, due to the piston effect of the fracturing fluid, fracturing open-hole horizontal wells Often only fractures at the end of the wellbore, which greatly reduces the fracturing effect. Therefore, layered fracturing of vertical wells and staged fracturing of horizontal wells are the development direction of fracturing stimulation technology at present. At present, the commonly used layered (stage) fracturing methods in the field mainly include: flow-limited fracturing, layered fracturing with temporary plugging agent, layered fracturing with mechanical packer, and layered fracturing with sand filling. The low perforation density required for flow-limited fracturing will hinder the expansion of the effective wellbore radius by perforation; during operation, excessive pressure drop may occur at the perforation channel and fracture entrance, which will affect the sand-carrying pressure The distribution of cracking fluid between layers; perforation by flow-restricted method provides a small fracture entrance area, which makes it easy for proppant to flow back during flowback and production. When fracturing open-hole horizontal wells, the simplest isolation method is to use a temporary plugging agent, which can be rock salt, benzoic acid tablets, or camphor balls. But the biggest problem with this method is that it is difficult to control the distance between the initiation points of the fractures along the wellbore; another important problem is that the proppant filling of the fractures near the wellbore cannot be controlled during the temporary plugging stage. Packer layering or staged fracturing technology can be implemented in cased wells. However, after the construction of a layer, the packer often occurs sand sticking, leading to downhole accidents. The problem with sand-packed layered fracturing is that the construction period is too long.

In recent years, my country's high-pressure water jet technology has continued to develop, and great progress has been made in cutting, rock breaking, and drilling. For example, in the Chinese Patent Publication No. CN100999989A, a high-pressure water jet deep penetration perforation and auxiliary fracturing method and device are disclosed. This application is the first application of the applicant in this case. A certain proportion of abrasive (usually quartz sand) is added to the fluid to form an abrasive jet, which is pressurized to 30-40MPa by a surface pump truck and transported to the perforating device and nozzle in the downhole through the tubing (the device can determine the layer and azimuth), inject a clean channel with a depth of 0.78-1.09 meters and a diameter of about 20mm in the formation; or move the pipe string and nozzle to achieve slotting in the downhole. The main advantages of this technology are: the penetration depth is greater than that of conventional perforation; it will not cause oil layer compaction damage like conventional perforation; Perforations and slotting. This technology has been applied to more than 10 wells on site, and the construction effect is good.

Chinese patent application No. 200510072121.8 discloses a "horizontal well fracturing method". The main disadvantages of this method are: it is impossible to control the initiation position of the fracture in the horizontal well section, and it cannot realize staged fracturing. In addition, it is difficult to operate on-site construction by analyzing the frictional resistance of the holes and judging the number of liquid inlet holes through the step-down discharge, which leads to inaccurate amounts of temporary plugging agents and cannot effectively plug the cracks that have been opened; Otherwise, the working reliability of the plugging agent will also seriously affect the plugging effect on the fractures that have been opened.

Chinese Patent No. 200710179500.6 describes a method of abrasive jet downhole perforation and slotted layered fracturing. This method is a new technology integrating abrasive perforation, hydraulic pack-off and fracturing. The packer can realize the fracturing of multiple intervals in sequence.

In the current known technology, the research on hydraulic jet fracturing method, downhole tool structure, etc. is relatively sufficient, but there is no report on the experimental device for the study of hydraulic jet fracturing mechanism.

In view of the defects in the above-mentioned known technologies, the inventor has developed the experimental device for detecting and simulating the pressure distribution in the hydraulic jet fracturing hole under the actual working conditions of the present invention based on years of experience in production design in this field and related fields. By simulating high-speed The pressure distribution in the formation hole when the jet is sprayed, and reliable experimental data are obtained.

Contents of the invention

The purpose of the present invention is to provide an experimental device for detecting the pressure distribution in the hydraulic jet fracturing hole under simulated actual working conditions, so as to detect the variation of the pressure in the simulated perforation hole with the axial position, and provide a basis for the study of the hydraulic jet fracturing mechanism. Reliable experimental data provide theoretical and experimental basis for on-site construction process design.

For this reason, the present invention proposes an experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions, wherein the experimental device includes: a support pipe body, a test piece with a through hole in the axial direction, and the test piece Fixed in the support tube body, one end of the test piece is closed, and the other end is provided with a spray plate, and the through hole provided on the spray plate corresponds to the through hole of the test piece; a liquid inlet pipe extends into Inside the support tube body, a nozzle is provided at the front end thereof, and the nozzle corresponds to the through hole on the injection plate; the outside of the test piece is arranged axially with a plurality of pressure-measuring joints that can be connected to a pressure-measuring device , the pressure measuring joint communicates with the through hole to detect the change of axial pressure in the through hole.

The above-mentioned experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions, wherein, one end of the support pipe body is provided with a first liquid outlet end piece, and the first liquid outlet end piece is sleeved On the liquid inlet pipe, one end is against the spray plate and the test piece, and the other end is against the first pressure cap screwed on the support tube body; the first liquid outlet end piece is The inner diameter is larger than the outer diameter of the liquid inlet pipe to form a return annular space, and the return annular space is connected with the first liquid outlet valve.

The above-mentioned experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions, wherein, the inner wall of the first liquid outlet end piece is convexly provided with a support portion that is sealed with the liquid inlet pipe, and the The inner diameter of the first liquid outlet end piece close to the injection plate is larger than the outer diameter of the liquid inlet pipe, forming the return annular space.

The above-mentioned experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions, wherein a pressure measuring hole is provided on the side wall of the first liquid outlet end piece close to the side of the jet plate, and the A pressure measuring joint capable of connecting a pressure measuring device is arranged in the pressure measuring hole.

The above-mentioned experimental device for testing and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions, wherein the liquid inlet pipe extends to the outside of the first pressure cap and forms a threaded connection with the first pressure cap The distance between the nozzle and the spray plate can be adjusted by rotating the liquid inlet pipe to adjust the spray distance of the nozzle; and the liquid inlet pipe is fixed at the adjusted position by a locking member.

The above-mentioned experimental device for testing and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions, wherein the spray distance of the nozzle can be continuously adjusted within the range of 0-70mm.

The above-mentioned experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions, wherein, the other end of the support pipe body is provided with a second liquid outlet end piece, and the second liquid outlet end piece One end abuts against the other end of the test piece; a groove is provided on the end surface of the second liquid outlet end piece facing the test piece, and a pressure measuring device connected to the groove is provided on its outer wall. A pressure measuring cap is arranged in the groove, and a tail pressure measuring joint is arranged in the pressure measuring hole.

As mentioned above, the experimental device for detecting and simulating the pressure distribution in the hydraulic jet fracturing hole under actual working conditions, wherein, the second liquid outlet end piece is also provided with a flow channel communicating with the through hole, and the second liquid outlet A valve is connected with the flow channel.

According to the experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions as described above, the support pipe body is provided with a long groove along the axial direction, and the pressure measuring joint is arranged in the long groove.

As mentioned above, the experimental device for detecting and simulating the pressure distribution in the hydraulic jet fracturing hole under the actual working condition, wherein the test piece is composed of a plurality of short connections arranged in sequence, and each of the short connections is sealed with each other. The middle part of the short-connection has holes, and the diameters of the holes are different, and a plurality of the short-connection holes arranged in sequence constitute the through hole.

In the experimental device for testing and simulating the pressure distribution in hydraulic jet fracturing holes under actual operating conditions as described above, the shape of the through hole is similar to that of the simulated actual formation hydraulic perforation hole.

The above-mentioned experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions, wherein each of the short-circuited side walls is provided with a pressure measuring hole communicating with the hole, and the pressure measuring A joint can be disposed within the pressure tap.

The above-mentioned experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions, wherein the short connection is a cylinder, one end of which is an embedded end, and the other end is a fastening end, and the fastening end forms The two adjacent short-connected embedded ends and the snap-fit ends are fitted and sealed to each other in the inner concave part that is in the same shape and size as the embedded end.

The experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions of the present invention can provide an experimental basis for theoretical/mechanism research of hydraulic jet fracturing technology. Hydraulic jet fracturing technology can open multiple fractures in sequence. Since no conventional mechanical packer is installed in the pipe string, in order to prevent the fracturing fluid from entering the fractures that have been opened when fracturing the next fracture, it is necessary to use "hydraulic packer" , that is, the high-speed injected fluid forms a "pressurization effect" in the formation hydraulic holes, and then the annular pressure is controlled to be lower than the formation fracture pressure, so that the injected fracturing fluid can enter the current target layer. The size of the "supercharged" under actual working conditions needs to be tested with the device of the present invention, so as to provide a theoretical and experimental basis for on-site construction process design.

Description of drawings

The following drawings are only intended to illustrate and explain the present invention schematically, and do not limit the scope of the present invention. in,

Figure 1 is a schematic diagram of the principle of hydraulic jet fracturing;

Fig. 2 is the structural schematic diagram of the experimental device of the present invention to detect and simulate the pressure distribution in the hydraulic jet fracturing hole of the simulated actual working condition;

Fig. 3 is the cross-sectional schematic view of the experimental device for detecting and simulating the pressure distribution in the hydraulic jet fracturing hole of the present invention;

Fig. 4 is a schematic sectional view along line A-A in Fig. 3;

Fig. 5 is the partially enlarged schematic view of I place in Fig. 3;

Fig. 6 is the experimental flow chart of the present invention.

Explanation of reference numbers:

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, below in conjunction with the accompanying drawings and preferred embodiments, the specific implementation of the experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions of the present invention, The structure, characteristics and functions are described in detail below. In addition, through the description of the specific implementation, the technical means and effects of the present invention to achieve the intended purpose can be understood more deeply and specifically. However, the attached drawings are only for reference and illustration, and are not used to limit the present invention. .

Fig. 2 is the structural schematic diagram of the experimental device of the present invention to detect and simulate the pressure distribution in the hydraulic jet fracturing hole of the simulated actual working condition; Fig. 4 is a schematic cross-sectional view along line A-A in Fig. 3; Fig. 5 is a partially enlarged schematic view of I in Fig. 3.

As shown in Fig. 2, Fig. 3, Fig. 4 and Fig. 5, the experimental device for detecting and simulating the pressure distribution in the hydraulic jet fracturing hole under the actual working conditions of the present invention includes: a supporting pipe body 1 having a through hole 20 in the axial direction In the test piece 2, the through hole 20 can simulate the shape of the hydraulic perforation hole in the formation. The test piece 2 is fixed in the support pipe body 1, one end of the test piece 2 is closed, and the other end is provided with a spray plate 3, and the through hole 31 provided on the spray plate 3 is connected with the test piece 2. Corresponding to the through hole 20, the injection plate 3 is used to simulate the opening of the downhole casing wall; a liquid inlet pipe 4 extends into the support pipe body 1, and its front end is provided with a nozzle 40, and the liquid inlet pipe 4 Connected with a high-pressure pump, the high-pressure working fluid of the high-pressure pump can be supplied to the nozzle 40 and sprayed out at a high speed by the nozzle 40 . The nozzle 40 corresponds to the through hole 31 on the injection plate 3; the outside of the test piece 2 is arranged with a plurality of pressure measuring joints 6 that can be connected to a pressure measuring device 60 along the axial direction, and the pressure measuring joints 6 communicates with the through hole 20 to detect the axial pressure change in the through hole 20 .

Further, one end of the support tube body 1 is provided with a first liquid outlet end piece 5, and the first liquid outlet end piece 5 is sleeved on the liquid inlet pipe 4, and one end thereof is against the spray plate 3 and test piece 2, and the other end against the first pressure cap 11 screwed on the support tube body 1; the inner diameter of the first liquid outlet end piece 5 is larger than the outer diameter of the liquid inlet pipe 1 , a return annular space 10 is formed between the two, and the return annular space 10 communicates with the first liquid outlet valve 50 .

Moreover, a pressure measuring hole is provided on the side wall of the first liquid outlet end piece 5 close to the injection plate 3 , and a pressure measuring joint 6 capable of connecting with a pressure measuring device is arranged in the pressure measuring hole.

As shown in Figure 3, in a specific embodiment, the first liquid outlet end piece 5 can be configured as a support portion 51 protruding from its inner wall, and the support portion 51 is sealed with the liquid inlet pipe 4 to form a To support the liquid inlet pipe 4. Moreover, the inner diameter of the first liquid outlet end piece 5 near the injection plate 3 is larger than the outer diameter of the liquid inlet pipe 4 , and the return annulus 10 is formed between them.

A feasible solution is that the liquid inlet pipe 4 extends to the outside of the first pressure cap 11 and forms a threaded connection with the first pressure cap 11, and the nozzle can be adjusted by rotating the liquid inlet pipe 4 40 and the spray plate 3 to adjust the spray distance of the nozzle 40; and the liquid inlet pipe 4 is fixed at the adjusted position by the locking member 41.

A preferred technical solution is that the spray distance of the nozzle 40 can be continuously adjusted within the range of 0-70mm.

In another specific embodiment, the other end of the support tube body 1 is provided with a second liquid outlet end piece 7, and one end of the second liquid outlet end piece 7 abuts against one end of the test piece 2, One end of the test piece 2 is closed. A groove 70 is provided on the end surface of the second outlet end member 7 facing the test piece 2, a pressure measuring hole 71 communicating with the groove 70 is provided on its outer wall, and a pressure measuring cap 72 is provided. Set in the groove 70 , the pressure measuring hole 71 is provided with a tail pressure measuring joint 61 through which the tail pressure measuring joint is connected with the pressure measuring device 60 to test the stagnation pressure of the liquid.

In addition, as shown in FIG. 3 , in a feasible solution, a test piece pressing block 8 is also provided in the support pipe body 1, and the test piece pressing block 8 is pressed against the second liquid outlet end piece 7, And one end of the test piece 2 is closed by the second pressure cap 13 threadedly connected with the support tube body 1 .

Further, as shown in the figure, in this embodiment, the first liquid outlet end arranged in the support pipe body 1 can be sequentially arranged through the first pressure cap 11 and the second pressure cap 13 arranged at both ends of the support pipe body 1 . Part 5, injection plate 3, test part 2, second liquid outlet part 7 and test piece pressing block 8 are compressed.

In order to facilitate operation, as shown in FIG. 3 , handles 111 and 131 can be provided on the first pressing cap 11 and the second pressing cap 13 .

A feasible technical solution is that the support tube body 1 is provided with a long groove 12 in the axial direction, and the pressure measuring joint 6 is arranged in the long groove 12 .

Further, in order to facilitate the adjustment of the length of the test piece 2, in a feasible solution, the test piece 2 can be composed of a plurality of short-connectors 21 arranged in sequence, each of the short-connectors 21 is sealed with each other, and each of the short-connectors 21 is sealed. The middle part of the short-circuit 21 has holes 210 , and the diameters of the holes 210 are different. A plurality of the holes 210 of the short-circuit 21 arranged in sequence constitute the through hole 20 . The shape of the through hole 20 is close to the simulated shape of the actual formation hydraulic perforation hole.

Specifically, a pressure measuring hole 211 communicating with the hole 210 is provided on the side wall of each of the shorts 21 , and the pressure measuring joint 6 can be disposed in the pressure measuring hole 211 .

As shown in FIG. 4 , in a specific technical solution, the pressure measuring hole 211 corresponds to the long groove 12 opened on the support pipe body 1 .

In addition, the short connector 21 is a cylinder, one end of which is an embedded end 212, and the other end is a fastening end 213, and the fastening end 213 forms an inner concave part that matches the shape and size of the embedded end 212. The embedded ends 212 and the fastening ends 213 of the two short connectors 21 are fitted and sealed with each other.

The working principle of the present invention is: Aiming at the core mechanism of hydraulic jet fracturing—the pressurization in the formation hole during high-speed jet injection (as shown in Figure 1), the hydraulic perforation hole 100 in Figure 1 is developed to simulate the actual working condition The experimental device for detecting and simulating the pressure distribution in the hydraulic jet fracturing hole under the actual working conditions of the present invention is established. In the present invention, the working fluid is pressurized by the high-pressure pump and sent to the liquid inlet pipe 4 through the high-pressure pipe, and then sprayed out by the nozzle 40. After passing through the through hole 31 of the injection plate 3 simulating the casing wall hole, it enters the through hole 20 simulating the perforation hole to realize the simulation process of jet fracturing. The simulated perforation hole is composed of a plurality of central holes 210 of short joints 21, on which a pressure measuring joint 6 can be installed, and a pressure sensor can be installed on the pressure measuring joint 6, through the pressure measuring device 60 connected with the pressure measuring joint 6 The pressure at different locations of the simulated perforation perforation can be measured and the axial pressure increase in the hole can be observed.

Adopting the device of the invention can provide an experimental basis for theoretical/mechanism research for hydraulic jet fracturing technology. Hydraulic jet fracturing technology can open multiple fractures in sequence. Since no conventional mechanical packer is installed in the pipe string, in order to prevent the fracturing fluid from entering the fractures that have been opened when fracturing the next fracture, it is necessary to use "hydraulic packer" , that is, the high-speed injected fluid forms a "pressurization effect" in the formation hole, and then the annular pressure is controlled to be lower than the formation fracture pressure, so that the injected fracturing fluid can enter the current target layer. The size of the "supercharged" under actual working conditions needs to be tested with the device of the present invention, so as to provide a theoretical and experimental basis for on-site construction process design.

The structure and working process of the present invention will be further described below in conjunction with a specific embodiment.

As shown in the figure, the experimental device of the present invention can be set on a support, and the support tube body 1 is fixed to the support member of the support by fixing screws. By rotating the first pressure cap 11 and the second pressure cap 13, the short connection 21 arranged in the support tube body 1 is pressed tightly, and the liquid inlet pipe 4 screwed with the first pressure cap 11 is rotated, within the range of 0-70mm The distance between the nozzle 40 and the injection plate 3 is continuously changed, and after the spray distance is adjusted, the position of the liquid inlet pipe 4 is fixed by the locking member 41 . The high-pressure working fluid is sent to the nozzle 40 through the liquid inlet pipe 4, and is sprayed out at a high speed by the nozzle 40, and enters the simulated perforation hole 210 after passing through the through hole 31 of the simulated casing wall hole to realize the simulation process of hydraulic injection. Wherein the liquid inlet pipe 4 has an internal pressure resistance of 35.0 MPa.

Wherein, the first fluid outlet valve 50 may be a set of needle valve assembly capable of adjusting displacement, which provides a channel for the working fluid entering the return annulus 10 from the hole 210 to return to the ground when simulating perforating.

According to the simulated hole size on the downhole casing wall surface, the injection plate 3 can be replaced, and the injection plate 3 with the through hole 31 corresponding to the required hole size is arranged in the support pipe body.

A combination of the multiple shorts 21 is sealed by the sealing rings at the embedding end 212 and the fastening end 213, and the holes in them can simulate the shape of holes in the formation. Each of the shorts 21 is a stepped cylinder with holes 210 of different sizes, for example, the length of each short 21 may be 24 mm, and the diameter of the holes is 20-40 mm.

One end of the pressure measuring joint 6 is threadedly connected with the pressure measuring hole 211 of the cylinder, and the pressure sensor detects the pressure value in the hole at this position through the pressure measuring joint 6 . For the position that does not require pressure measurement, a plug can be installed in the pressure measurement joint 6 to close it.

The second liquid outlet end piece 7 is also provided with a flow channel 72 communicating with the hole 210, and the second liquid outlet valve 73 is also a set of needle valve assembly that can adjust the displacement, and is connected with the flow channel. The 72 phases are connected to simulate the fluid loss of the working fluid (fracturing fluid) into the formation during the fracturing process.

In the experimental device of the present invention, the confining pressure at the nozzle 40 can be changed by adjusting the first liquid outlet valve 50 at the nozzle to simulate different well depth conditions; the spray distance can be changed by adjusting the liquid inlet pipe 4 (nozzle 40 and simulation sleeve The distance between the injection plates 3 of the pipe wall); the combination of different numbers of shorts 21 can obtain the simulated perforation 210 similar to the actual formation hydraulic perforation with different perforation diameters and perforation depths. Turn on the pump to inject the experimental fluid, and collect the data of multiple pressure sensors synchronously; change the combination of each experimental parameter, and repeat the experiment.

Please refer to Fig. 6, the experimental process of the present invention is: the nozzle 40 is installed on one end of the liquid inlet pipe 4; Put the first liquid outlet end piece 5 into it, adjust the spray distance, rotate the locking piece 41 to lock the liquid inlet pipe 4, tighten the first pressure cap, and the spray distance is fixed at this time; install the first liquid outlet valve 50 on the second A liquid outlet end piece 5; the test piece 2 is loaded from the other end of the support tube body 1, the second liquid outlet end piece 7 is abutted against the test piece 2, and the test piece pressing block 8 is loaded, Tighten the second pressure cap 13 at the tail end, connect the second liquid outlet valve with the flow channel 72 on the second liquid outlet end piece 7; fix the pressure measuring joint 6 and the tail pressure measuring joint 61 on the first outlet In the pressure measuring hole 211 on the liquid end piece 5, the pressure measuring hole 211 on the short connection 213 constituting the test piece 2, and the pressure measuring hole 71 on the second liquid outlet end piece 7, in each pressure measuring joint 6, the tail measuring A pressure sensor is installed in the crimping joint 61; the first and second liquid outlet valves 50, 73 are opened, and the pump is turned on for a pressure test; after the predetermined pressure is reached, the pressure value of each sensor is tested and collected by a pressure measuring device connected to the pressure sensor; Replace the nozzle, change the spray distance and other parameters, and repeat the test to obtain multiple sets of detection data.

The present invention can realize the following functions: 1. the nozzle 40 inlet pressure in the test piece 2 (measured by the pressure measuring joint arranged on the first liquid outlet end piece 5 close to the spray plate 3), confining pressure, crack extension pressure, etc. It can be adjusted within a certain range; ②The nozzle and the simulated casing wall hole can be replaced to change its diameter; ③The spray distance (the distance from the nozzle outlet to the casing inner wall) can be changed by adjusting the screw; ④The simulated perforation hole and crack are controlled by a The center hole of the series of adjustable nipples is composed of multiple pressure sensors installed on the adjustable nipples, which can measure the pressure at different positions of the simulated perforation holes.

The above descriptions are only illustrative specific implementations of the present invention, and are not intended to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the protection scope of the present invention. And it should be noted that each component of the present invention is not limited to the above-mentioned overall application, and each technical feature described in the description of the present invention can be selected to be used alone or in combination according to actual needs. Therefore, the present invention Other combinations and specific applications related to the invention of this case are naturally covered.

Claims (12)

1. An experimental device for detecting and simulating the pressure distribution in the hydraulic jet fracturing hole of simulated actual working conditions, characterized in that, the experimental device comprises: a support pipe body, a test piece with a through hole in the axial direction, and the test piece is fixed In the support tube body, one end of the test piece is closed, and the other end is provided with a spray plate, and the through hole provided on the spray plate corresponds to the through hole of the test piece; a liquid inlet pipe extends into the test piece. In the supporting tube body, the front end is provided with a nozzle, and the nozzle corresponds to the through hole on the injection plate; the outside of the test piece is arranged axially with a plurality of pressure measuring joints that can be connected to the pressure measuring device, The pressure measuring joint is connected with the through hole to detect the change of the axial pressure in the through hole; the test piece is composed of a plurality of short connections arranged in sequence, each of the short connections is mutually sealed, Each of the short-connected holes has a hole in the middle, and each hole has a different diameter, and a plurality of the short-connected holes arranged in sequence constitute the through hole. 2. The experimental device for detecting and simulating the pressure distribution in the hydraulic jet fracturing hole of the actual working condition as claimed in claim 1, wherein a first liquid outlet end piece is arranged in one end of the supporting pipe body, and the first liquid outlet end piece is arranged in the first end of the supporting pipe body. A liquid outlet end piece is sleeved on the liquid inlet pipe, one end of which is against the spray plate and the test piece, and the other end is against the first pressure cap screwed on the support tube body; The inner diameter of the first liquid outlet end piece is larger than the outer diameter of the liquid inlet pipe, forming a return annular space, and the return annular space communicates with the first liquid outlet valve. 3. The experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions as claimed in claim 2, wherein the inner wall of the first liquid outlet end piece is convexly provided with a pipe corresponding to the liquid inlet pipe. A sealed support part, and the inner diameter of the side of the first liquid outlet end piece close to the spray plate is larger than the outer diameter of the liquid inlet pipe, forming the return annulus. 4. The experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions as claimed in claim 3, characterized in that, the side wall of the first liquid outlet end piece near the side of the jet plate is provided with There is a pressure measuring hole, and a pressure measuring joint capable of connecting a pressure measuring device is arranged in the pressure measuring hole. 5. The experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual operating conditions according to claim 2, wherein the liquid inlet pipe extends to the outside of the first pressure cap and is connected to the The first pressure cap constitutes a threaded connection, and the distance between the nozzle and the spray plate can be adjusted by rotating the liquid inlet pipe to adjust the spray distance of the nozzle; and the liquid inlet pipe is fixed on the Adjusted position. 6 . The experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual operating conditions according to claim 3 , wherein the spray distance of the nozzle can be continuously adjusted within the range of 0-70 mm. 7. The experimental device for detecting and simulating the pressure distribution in the hydraulic jet fracturing hole of the actual working condition as claimed in claim 1, wherein the other end of the supporting pipe body is provided with a second liquid outlet end piece, and the One end of the second liquid outlet end piece abuts against the other end of the test piece; a groove is arranged on the end surface of the second liquid outlet end piece facing the side of the test piece, and the outer wall is provided with the same groove as the said test piece. The groove is connected to the pressure measuring hole, and a pressure measuring cap is arranged in the groove, and a tail pressure measuring joint is arranged in the pressure measuring hole. 8. The experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual operating conditions as claimed in claim 7, characterized in that, the second liquid outlet end piece is also provided with a hole communicating with the through hole. a flow channel, and the second liquid outlet valve is connected with the flow channel. 9. The experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual working conditions as claimed in claim 1, wherein the support pipe body is provided with a long groove along the axial direction, and the pressure measuring joint is arranged at in the long slot. 10. The experimental device for detecting and simulating the pressure distribution in hydraulic jet fracturing holes under actual operating conditions according to any one of claims 1 to 9, wherein the shape of the through hole is consistent with the simulated actual formation hydraulic jet The holes are similar in shape. 11. The experimental device for detecting and simulating the pressure distribution in the hydraulic jet fracturing hole of any one of claims 1 to 9, characterized in that, each of the short-connected side walls is provided with a The pressure measuring holes connected with the holes, the pressure measuring joints can be arranged in the pressure measuring holes. 12. The experimental device for detecting and simulating the pressure distribution in the hydraulic jet fracturing hole of any one of claims 1 to 9, wherein the short connection is a cylinder, one end of which is an embedded end, The other end is a snap-fit end, and the snap-fit end forms an inner concave part matching the shape and size of the embedded end, and two adjacent short-connected embedded ends and snap-fit ends are fitted and sealed with each other.