Integrated high-strength push-pull valve and integrated device for hydraulic fracturing test

Abstract

The invention provides an integrated high-strength push-pull valve for a hydraulic fracturing test and an integrated device, and belongs to the technical field of fracturing tests. The integrated high-strength push-pull valve for the hydraulic fracturing test comprises a valve middle part and a valve body, the first end of the valve is connected with a connecting pipe; the valve body is in threaded connection with the second end of the valve middle, a seat seal channel water outlet groove is formed in the position, connected with the valve body, of the valve middle, valve elements are arranged in the valve middle and an inner cavity of the valve body, and the end, extending to the outside, of each valve element is fixedly connected with a connector. The valve and the inner cavity of the valve body allow the valve element to move axially so as to achieve internal switching of a fracturing channel and a setting channel. A seat sealing water channel between the push-pull valve and the packer is changed from an original external rubber water pipe connection into an internal water flowing integrated pipeline through the connecting pipe, the influence of impurities in a hole is avoided, and blockage and inconvenient loading and unloading caused by excessive use of a sealing tape due to the external water pipe are avoided.

Description

Technical Field

[0001] The present application relates to the field of fracturing testing, and in particular to an integrated high-strength push-pull valve and an integrated device for hydraulic fracturing testing. Background Art

[0002] At present, the hydraulic fracturing (HF) in-situ stress measurement method is one of the most important geostress measurement technologies. As one of the most important physical properties of the solid crust, geostress attributes are essential basic data for the construction of major national infrastructure, key deep mineral resources, and the exploration and development of energy materials. Among all geostress measurement methods, hydraulic fracturing testing technology has become the most direct and effective method for determining rock mass geostress with its three major characteristics and advantages: the test section is not limited by depth, the theoretical calculation does not require the participation of rock mechanical parameters, and the test results are relatively stable. It has become recognized at home and abroad as the most direct and effective method for determining rock mass geostress, and is widely used in tunnels, mines, energy development and other fields.

[0003] MK Hubbert and D.G. Willis believed that deep underground geostress is both vertical and horizontal, emphasizing that the two horizontal principal stresses are not necessarily equal and are independent of the vertical stress, rather than being in a hydrostatic state. These theoretical insights and elastic mechanics models remain the foundation of our understanding of hydraulic fracturing today (Hubbert and Willis, 1957; Kirsch, 1898). Haimson and Fairhurst (1967) pointed out that cracks in well walls are related to three factors: 1) crustal stress, 2) the differential stress between the hydraulic fracturing fluid pressure and the pore water pressure, and 3) the radial flow rate of rock mass infiltration. BC Haimson and C. Fairhurst extended the poroelastic theory to pressure-bearing boreholes and generalized the elastic model of MK Hubbert and D.G. Willis to consider fluid penetration, thus refining the basic theory of geostress testing for hydraulic fracturing. In the early 1970s, American scholars B.C. Haimson and C. Fairhurst, drawing on hydraulic fracturing production stimulation techniques in the petroleum industry, proposed the theory of in-situ hydraulic fracturing stress measurement, along with the corresponding measurement techniques and procedures. Their work laid a solid foundation for the development of the HF method, which has since become a research hotspot. In 1970, a research team led by H.V. Schonfeldt and C. Fairhurst conducted the first real hydraulic fracturing stress measurement engineering practice in shallow boreholes (including vertical and horizontal holes) in an underground granite rock mass in Minnesota. This experiment verified the feasibility of hydraulic fracturing as a field measurement method (Schonfeldt and Fairhurst, 1972). In 1971, a branch of the United States Geological Survey financially supported hydraulic fracturing stress measurement in the Rangely oil field in Colorado. This was the first "deephole hydraulic fracturing stress measurement" and paved the way for the widespread acceptance of this method. As a result, hydraulic fracturing has established its dominant position in geostress testing, particularly in deep geostress testing. Hydraulic fracturing geostress measurement in my country began in the early 1980s, when it was introduced from the United States by the Institute of Crustal Stress of the China Earthquake Administration through international collaboration. In October 1980, my country successfully conducted the first in situ stress measurement using hydraulic fracturing in Yi County, Baoding City, Hebei Province (Li Fangquan et al., 1980). Subsequently, Chen Qunzhe et al., addressing the challenges of three-dimensional geostress measurement using hydraulic fracturing, conducted nonlinear research on data processing using multiple intersecting boreholes for hydraulic fracturing stress measurement and proposed a new theoretical model based on the minimum principal stress failure criterion.From 1992 to 1996, the most representative work in my country on hydraulic fracturing ground stress testing technology was the Sino-Japanese cooperation project between the Institute of Crustal Stress of the China Earthquake Administration and the Central Research Institute of Electric Power Research Institutes of Japan, which achieved the miniaturization and lightweight of the testing equipment, laying a solid foundation for the widespread application of hydraulic fracturing ground stress testing methods in my country.

[0004] At present, hydraulic fracturing in-situ stress measurement equipment is mainly divided into five categories: (1) heavy-duty cable-type hydraulic fracturing in-situ stress measurement equipment, represented by the Swiss MESY-SOLEXPERTS equipment; (2) lightweight cable-type hydraulic fracturing in-situ stress measurement equipment, mainly represented by the shallow hole test equipment manufactured by Japan's OYO company and the shallow hole test equipment manufactured by Australia's CSIRO organization; (3) heavy-duty cable-type comprehensive test equipment, represented by the new hydraulic fracturing test equipment made by Professor Cornet of France and Professor Thiercelin of the United States that combines hydraulic fracturing testing with other geophysical logging equipment; (4) deep well mother-and-child hole high-precision test equipment, represented by the BABHY test equipment manufactured by Tohoku University of Japan; (5) detachable lightweight hydraulic fracturing test equipment, represented by the drill pipe hydraulic fracturing in-situ stress measurement equipment widely used in China.

[0005] The measurement system widely used in China consists of six parts: pressure fluid control system, high-pressure water pump, power system, data recording system, jumper packer and high-pressure fluid delivery system. This measurement system is divided into two categories. One is for shallow holes of 100m, we can use drill pipe and high-pressure hose to supply water to the packer and fracturing section respectively to achieve fracturing. The other equipment is for deep hole measurement over 100m, we use a conversion valve to supply pressure liquid to the fracturing section and packer respectively. The test system diagram is as follows Figure 16 、 Figure 17 As shown;

[0006] From the previous analysis, we can know that the dual-loop test system connects a slender high-pressure water pipe to the outside of the packer and the drill pipe to form two pressure channels.

[0007] The above-mentioned prior art solutions have the following defects:

[0008] As underground projects become deeper and deeper, deep geological boreholes will become common, and generally only a single-loop test system with a push-pull valve can be used for testing.

[0009] In some single-loop test systems, an external rubber water pipe is used as a sealing channel between the push-pull valve and the packer, and a high-pressure sealing tape is used to connect and squeeze the seal at the interface. This practice can easily lead to blockage, difficulty in installation, and insufficient sealing, which in turn leads to test failure. Summary of the Invention

[0010] In order to make up for the above shortcomings, the present application provides an integrated high-strength push-pull valve for hydraulic fracturing testing, which aims to improve the problem of blockage and inconvenience in loading and unloading caused by excessive use of sealing tape due to external water pipes.

[0011] In a first aspect, an embodiment of the present application provides an integrated high-strength push-pull valve for hydraulic fracturing testing, comprising a valve center and a valve body;

[0012] The first end of the valve is connected to a connecting pipe; the valve body is threadedly connected to the second end of the valve, and a water outlet groove for a seat sealing channel is constructed inside the valve at the connection between the valve and the valve body. A valve core is built into the valve and the inner cavity of the valve body, and one end of the valve core extending to the outside is fixedly connected to a joint. The valve and the inner cavity of the valve body allow the valve core to move axially to realize internal switching of the fracturing channel and the seat sealing channel, which are used to realize fracturing and expansion of the packer respectively.

[0013] In a preferred embodiment of the present invention, a top screw hole is opened on the side of the valve body, a top screw is connected to the inner thread of the top screw hole, the side of the valve is threadedly connected to the top screw, three top screws are provided, and a mesh for filtering is placed between the top screw and the threaded hole.

[0014] In a preferred embodiment of the present invention, a holding ring is placed outside the valve core, the inner side of the holding ring is threadedly connected to the valve core, a limiting groove is provided on the surface of the valve core for circumferentially fixing the holding ring, and a wrench is detachably connected to the outer side of the holding ring for facilitating installation and disassembly of the equipment.

[0015] In a preferred embodiment of the present invention, a nut is mounted on the valve core surface, with one side of the nut fitting over the end of the ring and the other side fitting over the end of the connector. Its core function is to provide additional tightening force for the threaded connection, preventing loosening of components under high-frequency vibration or high-pressure impact.

[0016] In a preferred embodiment of the present invention, the holding ring is arranged outside the valve body, the holding ring is placed between the spare nut and the valve body, and the outer diameters of the holding ring and the spare nut are smaller than the outer diameter of the valve body.

[0017] In a preferred embodiment of the present invention, the first end of the valve core is secured to the valve body via a threaded connection, while the second end of the valve core moves axially within the valve body and the valve body to switch between the fracturing channel and the sealing channel. A plug is installed at the second end of the valve core. A high-pressure fluid channel within the valve core directs high-pressure fluid from the filter tube through multiple outlet holes at the other end to the sealing / fracturing channel.

[0018] In a preferred embodiment of the present invention, one end of the connector is connected to the valve core, and the other end of the connector is connected to a filter tube for filtering liquid. The connector has a built-in guide channel, which guides the high-pressure fluid filtered by the filter tube into the interior of the valve core.

[0019] In a preferred embodiment of the present invention, the first end of the connecting pipe is threadedly connected to one end of the valve, and the second end of the connecting pipe is threadedly connected to the steel head of the upper packer. The connecting pipe is internally provided with a sealing channel and a fracturing channel corresponding to the valve. The sealing channel directs high-pressure fluid to the packer to expand and seal it, while the fracturing channel directs high-pressure fluid to the fracturing pipe to cause fracturing.

[0020] In a preferred embodiment of the present invention, a first sealing groove is provided on the inner wall of the valve, a sealing ring A is clamped in the first sealing groove, a second sealing groove is provided on the inner wall of the valve body, a sealing ring B is clamped in the second sealing groove, and the sealing ring A and the sealing ring B are both sealed and fitted with the outer surface of the valve core.

[0021] In a preferred embodiment of the present invention, the sealing rings A are arranged in three groups at intervals, each group is provided with two sealing rings A, and two sealing rings B are provided. The sealing rings A and the sealing rings B are both rubber sealing rings.

[0022] In a second aspect, an embodiment of the present invention further provides an integrated device for hydraulic fracturing testing, comprising a double-layer filter for hydraulic fracturing testing as described above; and an anti-blocking fracturing pipe for hydraulic fracturing testing, comprising

[0023] A fracturing flower tube, wherein a central channel is opened in the fracturing flower tube, and a countersunk one-way high-pressure fluid output channel connected to the central channel is opened on the outer surface of the fracturing flower tube;

[0024] Connecting steel heads, two of which are provided, and the two connecting steel heads are respectively sealed and docked with the two ends of the fracturing flower tube, the connecting steel head is provided with a sealing channel, the fracturing flower tube is provided with a sealing through-hole, the port of the sealing through-hole is docked with the sealing channel, and a fracturing channel is provided in the center of the connecting steel head, and the fracturing channel is connected with the central channel.

[0025] Beneficial effects:

[0026] 1. By connecting a push-pull valve between the drill pipe and the double plug packer, the high-pressure fluid channel switching between the packer seat seal section and the fracturing section is achieved. It is suitable for rapid and continuous testing of deep drilling holes, with simple and convenient operation and features:

[0027] The sealing water channel between the push-pull valve and the packer is changed from the original external rubber water pipe connection to an integrated processing design with internal water flow;

[0028] The sealing measures of the old push-pull valve, which use two hard and one soft O-type rubber sealing rings, are changed to using all soft sealing rings for sealing. This can facilitate installation and greatly improve implementation efficiency.

[0029] 2. During borehole hydraulic fracturing testing of rock masses, the system rapidly switches high-pressure fluid channels, precisely controlling the pressurization and depressurization processes to ensure test accuracy and safety. Compared to dual-circuit test systems that require external rubber hoses, the single-circuit test system implemented by this push-pull valve allows for rapid switching of high-pressure fluid channels and enables testing of deep boreholes. Furthermore, the sealing waterway between the push-pull valve and the packer is replaced by an integrated internal water pipe via a connecting pipe, eliminating the effects of impurities within the borehole and avoiding blockages and inconvenience in assembly and disassembly caused by excessive use of sealing tape due to the external hose. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the implementation methods of the present application, the following is a brief introduction to the drawings required for use in the implementation methods. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 This is a schematic diagram of the structure of an integrated high-strength push-pull valve for hydraulic fracturing testing provided in an embodiment of the present application;

[0032] Figure 2 A schematic diagram of a cross-section structure of a valve provided in an embodiment of the present application;

[0033] Figure 3 A schematic diagram of the cross-section structure of a valve body provided in an embodiment of the present application;

[0034] Figure 4 A schematic diagram of a cutaway structure of a valve core provided in an embodiment of the present application;

[0035] Figure 5 A schematic diagram of the ring structure provided for the implementation of this application;

[0036] Figure 6 A schematic diagram of the joint structure provided in an embodiment of the present application;

[0037] Figure 7 A schematic diagram of the cross-section structure of the connecting pipe provided in an embodiment of the present application;

[0038] Figure 8 A schematic diagram of the air hole plug structure provided in an embodiment of the present application;

[0039] Figure 9A schematic diagram of the seat seal position structure of the push-pull valve structure provided in an embodiment of the present application;

[0040] Figure 10 This is a schematic diagram of the three-dimensional structure of the anti-blocking fracturing pipe provided in an embodiment of the present application;

[0041] Figure 11 A schematic diagram of a cutaway three-dimensional structure provided in an embodiment of the present application;

[0042] Figure 12 A schematic diagram of the three-dimensional structure of a fracturing flower pipe provided in an embodiment of the present application;

[0043] Figure 13 A schematic diagram of the three-dimensional structure of the anti-backflow assembly provided in an embodiment of the present application;

[0044] Figure 14 A schematic diagram of the three-dimensional structure of the limiting groove provided in an embodiment of the present application;

[0045] Figure 15 Schematic diagram of the three-dimensional structure of the connection between the sealing ring and the compression spring provided in the embodiment of the present application

[0046] Figure 16 A schematic diagram of the structure of a dual-loop test system composed of a hydraulic fracturing in-situ stress measurement device provided in an embodiment of the present application;

[0047] Figure 17 Schematic diagram of the structure of a single-loop test system composed of a hydraulic fracturing in-situ stress measurement device provided in an embodiment of the present application.

[0048] In the figure: 800, valve center; 801, sealing ring A; 810, connecting pipe; 820, air hole plug; 900, valve body; 901, top screw; 902, sealing ring B; 910, valve core; 911, screw plug; 920, holding ring; 930, spare nut; 940, connector. DETAILED DESCRIPTION

[0049] In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; they may refer to direct connection or indirect connection through an intermediate medium; they may refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0050] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0051] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0052] See also Figures 1-9 The present invention provides an integrated high-strength push-pull valve for hydraulic fracturing testing, comprising a valve center 800 and a valve body 900;

[0053] The first end of the valve 800 is connected to a connecting pipe 810; the valve body 900 is threadedly connected to the second end of the valve 800, and a water outlet groove for a seat sealing channel is constructed inside the connection between the valve 800 and the valve body 900. A valve core 910 is built into the valve and the inner cavity of the valve body, and one end of the valve core 910 extending to the outside is fixedly connected to a joint 940. The valve and the inner cavity of the valve body allow the valve core 910 to move axially to realize internal switching of the fracturing channel and the seat sealing channel, which are used to realize fracturing and expansion of the isolation device respectively.

[0054] In a specific embodiment of the present invention, a jackscrew hole is provided on the side of the valve body 900. A jackscrew 901 is threadedly connected to the inner surface of the jackscrew hole. The side of the valve body 800 is threadedly connected to the jackscrew 901. The jackscrews 901 are M8 studs, and there are three jackscrews 901. A mesh is placed between the jackscrews and the threaded hole to serve as a filter. The jackscrew hole serves as an exhaust hole, and the interior of the jackscrew is also hollow. To prevent impurities in the drilled hole from entering the push-pull valve, a mesh made of a filter is added to act as a filter. The jackscrew also serves to compress the mesh.

[0055] In a specific embodiment of the present invention, a holding ring 920 is placed outside the valve core 910, and the inner side of the holding ring 920 is threadedly connected to the valve core 910. A limiting groove for circumferentially fixing the holding ring 920 is provided on the surface of the valve core 910, and a wrench is detachably connected to the outer side of the holding ring 920 to facilitate installation and disassembly of the equipment.

[0056] In this embodiment of the present invention, a nut 930 is sleeved on the surface of the valve core 910. One side of the nut 930 engages with the end of the ring 920, and the other side of the nut 930 engages with the end of the connector 940. Its core function is to provide additional tightening force for the threaded connection, preventing the components from loosening under high-frequency vibration or high-pressure impact.

[0057] In a specific embodiment of the present invention, the holding ring 920 is arranged outside the valve body 900, and the holding ring 920 is placed between the spare nut 930 and the valve body 900. The outer diameters of the holding ring 920 and the spare nut 930 are smaller than the outer diameter of the valve body 900.

[0058] In a specific embodiment of the present invention, the first end of the valve core 910 is secured to the valve core 800 via a threaded connector 940. The second end of the valve core 910 is axially movable within the valve body 900 and valve core 800 to switch between the fracturing channel and the sealing channel. A plug 911 is mounted on the second end of the valve core 910. The high-pressure fluid channel within the valve core 910 directs high-pressure fluid from the filter tube to the sealing / fracturing channel through multiple outlet holes at the other end.

[0059] In a specific embodiment of the present invention, one end of the connector 940 is connected to the valve core 910, and the other end of the connector 940 is connected to the filter tube for filtering liquid. The connector 940 has a built-in guide channel, which guides the high-pressure fluid filtered by the filter tube to the inside of the valve core 910.

[0060] In a specific embodiment of the present invention, the first end of the connecting pipe 810 is threadedly connected to one end of the valve 800, and the second end of the connecting pipe 810 is threadedly connected to the steel head of the upper packer. The connecting pipe 810 is internally provided with a sealing channel and a fracturing channel corresponding to the valve 800. The sealing channel guides high-pressure fluid to the packer to expand and seal it, while the fracturing channel guides high-pressure fluid to the fracturing pipe to cause fracturing.

[0061] In a specific embodiment of the present invention, a first sealing groove is provided on the inner wall of the valve 800, a sealing ring A801 ​​is clamped in the first sealing groove, a second sealing groove is provided on the inner wall of the valve body 900, a sealing ring B902 is clamped in the second sealing groove, and both the sealing ring A801 ​​and the sealing ring B902 are sealed and fitted with the outer surface of the valve core 910. The material of the valve 800 is 304 stainless steel, and the two ends of the valve 800 are respectively threadedly connected to the valve body 900 and the connecting pipe 810. Figure 2It can be seen that one end of the valve 800 is connected to the valve body 900 and the valve core 910 is allowed to move axially inside the two to achieve high-pressure fluid channel switching. The interior of the valve 800 also has a fracturing channel and a seat sealing channel for switching, which are used for hydraulic fracturing and packer expansion respectively.

[0062] In a specific embodiment of the present invention, the sealing rings A801 ​​are arranged in three groups at intervals, each group is provided with two sealing rings A801, and two sealing rings B902 are provided. The sealing rings A801 ​​and the sealing rings B902 are both O-type rubber sealing rings of the same specifications.

[0063] In a specific embodiment of the present invention, the valve 800 is provided with drain holes, arranged opposite each other on the side of the valve 800. These drain holes are connected to air vent plugs 820, which are connected to the valve 800 via springs. The springs connect the valve 800 to the outside of the valve, ensuring that it only allows water to flow out of the valve. This allows high-pressure fluid from the fracturing stage to flow along the fracturing channel to the drain holes during drainage, while also preventing impurities in the test hole from entering the sealing channel or the fracturing channel.

[0064] like Figures 10 to 15 The embodiment of the present invention further provides an integrated device for hydraulic fracturing test, comprising a double-layer filter for hydraulic fracturing test as described above; and an anti-blocking fracturing pipe for hydraulic fracturing test, comprising

[0065] A fracturing flower tube 100 is provided with a central channel 110 therein and a countersunk one-way high-pressure fluid output channel 130 communicating with the central channel 110 is provided on the outer surface of the fracturing flower tube 100;

[0066] The connecting steel head 300 is provided with two connecting steel heads 300, and the two connecting steel heads 300 are respectively sealed and docked with the two ends of the fracturing flower tube 100. The connecting steel head 300 is provided with a sealing channel 310, and the fracturing flower tube 100 is provided with a sealing through hole. The port of the sealing through hole is docked with the sealing channel 310. The center of the connecting steel head 300 is provided with a fracturing channel 330, and the fracturing channel 330 is connected with the central channel 110.

[0067] A backflow prevention assembly 500 is also provided. The backflow prevention assembly 500 includes a countersunk screw A510 and a tension spring 530. The countersunk screw A510 is inserted into the countersunk one-way high-pressure fluid output channel 130. One end of the tension spring 530 is connected to the radial through hole at the end of the countersunk screw A510. The other end of the countersunk screw A510 is connected to a top screw 550 for adjusting the tension.

[0068] In a specific embodiment of the present invention, the countersunk one-way high-pressure fluid output channel 130 is arranged in pairs, including a countersunk hole A and a countersunk hole B. The countersunk hole A and the countersunk hole B are symmetrically arranged on both sides of the central channel 110. The countersunk screw A510 is inserted into the countersunk hole A, and the countersunk screw B570 is inserted into the countersunk hole B. The end of the countersunk screw B570 is provided with an internal threaded hole, and the top screw 550 is connected to the internal threaded hole. The countersunk screw A510 and the countersunk screw B570 are coaxially arranged.

[0069] After long-term use, the sealing contact surface between the countersunk screw A510 and the countersunk one-way high-pressure fluid output channel 130 may wear out, resulting in failure of anti-backflow. For this reason, the following is a specific implementation plan of the anti-blocking fracturing pipe according to the hydraulic fracturing test of this application with reference to the accompanying drawings:

[0070] Specifically, in a specific embodiment of the present invention, a limiting groove 190 is opened on the surface of the fracturing flower tube 100, and a sealing ring 191 is slidably inserted in the limiting groove 190. A compression spring 193 is connected between the lower end of the sealing ring 191 and the bottom of the limiting groove 190, and the upper end of the sealing ring 191 is in contact with the conical surface of the countersunk screw A510.

[0071] In a specific embodiment of the present invention, the limiting groove 190 is coaxially arranged with the countersunk one-way high-pressure fluid output channel 130, the limiting groove 190 is a blind hole groove, the lower end of the compression spring 193 is fixedly connected to the bottom of the limiting groove 190, the upper end of the compression spring 193 is fixedly connected to the sealing ring 191, and the conical surface of the countersunk screw A510 is provided with a sealing groove D, and the upper end of the sealing ring 191 is fitted and inserted into the sealing groove D.

[0072] After the inspection is completed, as the high-pressure liquid in the central channel 110 recedes, the countersunk screw A510 is reset under the action of the tension spring 530, and the upper end of the sealing ring 191 contacts the end face of the countersunk screw A510 to achieve a contact seal, effectively preventing the backflow of external liquid. After the upper end of the sealing ring 191 is worn, the elastic action of the compression spring 193 pushes the sealing ring 191 to extend outward to compensate, and always contacts and seals with the conical surface of the countersunk screw A510, so that the sealing contact is always maintained, the equipment service life is delayed, the maintenance cost is reduced, and the backflow caused by airtightness failure due to wear is effectively avoided.

[0073] Working principle of the integrated high-strength push-pull valve for hydraulic fracturing test:

[0074] Sealing operation: During the process of drilling the drill pipe, when the valve core 910 moves axially in the inner cavity of the valve 800 to the top of the valve 800, the high-pressure water flow that has been filtered by the filter and flows into the joint 940 comes out from the water outlet of the valve core 910, enters the sealing water channel through the water outlet groove formed by the valve core 910 and the valve 800, and enters the upper and lower separators through the connecting pipe 810, so that the seal is pressurized and expanded to adhere to the wall of the borehole.

[0075] Fracturing operation: After the sealing operation is completed, fracturing begins. High-pressure water flows through the drill pipe and is filtered by the filter before entering the valve core 910 of the push-pull valve. At this time, the valve core 910 moves axially to the bottom end of the inner cavity of the valve 800, enters the fracturing water channel through the water inlet of the valve 800 through the water outlet hole of the valve core 910, and finally enters the connecting pipe 810 and the central pipe of the packer from the water outlet channel of the valve 800 to reach the fracturing pipe for directionally transporting to the target section aperture to complete the fracturing operation. In the prior art, the fracturing operation requires the valve core 910 to be pushed completely to the bottom end of the valve 800, that is, the valve core 910 has and only has one very precise connection position with the fracturing water channel.

[0076] It should be noted that, as can be clearly seen in the diagram, during the seat seal operation within the push-pull valve, high-pressure water flows through the seat seal channel into the separator, while during the fracturing operation, high-pressure water flows through the fracturing channel into the open-hole borehole of the fracturing test section. The water in these two channels is spatially isolated and independent from each other, without interfering with each other. It should also be noted that during the axial movement of the valve core 910, multiple sealing rings are placed between the valve core 910 and the valve core 800, ensuring that the high-pressure water flows only into one channel at each position, while also maintaining the packer pressure during the seat seal phase and the fracturing pressure during the pressure phase.

[0077] The foregoing is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures.

Claims

1. An integrated high-strength push-pull valve for hydraulic fracturing testing, characterized in that: include A valve (800), wherein a first end of the valve (800) is connected to a connecting pipe (810); A valve body (900) is threadedly connected to the second end of the valve (800), and a water outlet groove for a sealing channel is constructed inside the connection between the valve (800) and the valve body (900). A valve core (910) is built into the valve and the inner cavity of the valve body. One end of the valve core (910) extending to the outside is fixedly connected to a joint (940). The inner cavity of the valve and the valve body allows the valve core (910) to move axially to realize internal switching of the fracturing channel and the sealing channel, which are used to realize fracturing and expansion of the packer respectively.

2. The integrated high-strength push-pull valve for hydraulic fracturing testing according to claim 1, characterized in that: A top screw hole is provided on the side of the valve body (900), and a top screw (901) is threadedly connected to the top screw hole. The side of the valve (800) is threadedly connected to the top screw (901). There are three top screws (901), and a mesh is placed between the top screw and the threaded hole to serve as a filter.

3. The integrated high-strength push-pull valve for hydraulic fracturing testing according to claim 1, characterized in that: The valve core (910) is provided with an embracing ring (920) on the outside. The inner side of the embracing ring (920) is threadedly connected to the valve core (910). A limiting groove for circumferentially fixing the embracing ring (920) is provided on the surface of the valve core (910).

4. The integrated high-strength push-pull valve for hydraulic fracturing testing according to claim 3, characterized in that: The surface of the valve core (910) is provided with a spare nut (930), one side of the spare nut (930) is fitted with the end of the ring (920), and the other side of the spare nut (930) is fitted with the end of the connector (940).

5. The integrated high-strength push-pull valve for hydraulic fracturing testing according to claim 4, characterized in that: The holding ring (920) is arranged outside the valve body (900), and the holding ring (920) is placed between the spare nut (930) and the valve body (900). The outer diameters of the holding ring (920) and the spare nut (930) are smaller than the outer diameter of the valve body (900).

6. The integrated high-strength push-pull valve for hydraulic fracturing testing according to claim 1, characterized in that: The first end of the valve core (910) is connected to and fixed to the threaded joint (940), and the second end of the valve core (910) moves axially in the valve (800) and inside the valve body (900) to achieve switching between the fracturing channel and the sealing channel. A wire plug (911) is installed at the second end of the valve core (910).

7. The integrated high-strength push-pull valve for hydraulic fracturing testing according to claim 1, characterized in that: One end of the connector (940) is connected to the valve core (910), and the other end of the connector (940) is connected to a filter tube for filtering liquid. The connector (940) is internally provided with a guide channel, and the guide channel guides the high-pressure fluid filtered by the filter tube into the interior of the valve core (910).

8. The integrated high-strength push-pull valve for hydraulic fracturing testing according to claim 1, characterized in that: The first end of the connecting pipe (810) is threadedly connected to one end of the valve (800), and the second end of the connecting pipe (810) is threadedly connected to the steel head of the upper packer. The connecting pipe (810) is provided with a sealing channel and a fracturing channel corresponding to the valve (800) inside.

9. The integrated high-strength push-pull valve for hydraulic fracturing testing according to claim 1, characterized in that: A first sealing groove is provided on the inner wall of the valve (800), and a sealing ring A (801) is clamped in the first sealing groove. A second sealing groove is provided on the inner wall of the valve body (900), and a sealing ring B (902) is clamped in the second sealing groove. Both the sealing ring A (801) and the sealing ring B (902) are sealed and fitted with the outer surface of the valve core (910).

10. An integrated device for hydraulic fracturing testing, characterized in that: include The double-layer filter for hydraulic fracturing testing according to any one of claims 1 to 9; as well as The anti-blocking fracturing pipe for hydraulic fracturing test is characterized by comprising A fracturing flower tube (100), wherein a central channel (110) is provided in the fracturing flower tube (100), and a countersunk one-way high-pressure fluid output channel (130) communicating with the central channel (110) is provided on the outer surface of the fracturing flower tube (100); A connecting steel head (300), wherein two connecting steel heads (300) are provided, and the two connecting steel heads (300) are sealed and docked with the two ends of the fracturing flower tube (100) respectively, the connecting steel head (300) is provided with a sealing channel (310), the fracturing flower tube (100) is provided with a sealing through hole, the port of the sealing through hole is docked with the sealing channel (310), and the center of the connecting steel head (300) is provided with a fracturing channel (330), and the fracturing channel (330) is connected with the central channel (110).

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