Hydraulic fracturing ground stress measuring device

Abstract

The invention belongs to the technical field of hydraulic fracturing, and discloses a hydraulic fracturing ground stress measuring device which comprises a water inlet module, a control valve, a packing module and a water passing valve which are communicated in sequence. The water inlet module communicates with the top of the control valve; a fluid switching assembly is arranged in the control valve and used for switching fluid channels. A first channel and a second channel are arranged at the bottom of the control valve; the first channel penetrates through the test section of the packing module, is connected with a water passing valve and is used for discharging gushing water or injecting water into the test section; the second channel injects water into two groups of expandable packers of the packing module, so that the expandable packers are expanded to form a test section; the test section is used for bearing high-pressure water to generate rock stratum cracks so as to calculate crustal stress parameters; a cover plate capable of being opened and closed is arranged at the bottom of the water passing valve and communicated with the first channel and the second channel, and the cover plate is opened under the water gushing working condition or closed under the water injection working condition. According to the invention, the measuring device can be freely lowered in the water gushing drill hole, and the controllability of the control valve under the action of high-pressure water is ensured.

Description

Technical Field

[0001] The invention discloses a hydraulic fracturing ground stress measuring device, belonging to the technical field of hydraulic fracturing. Background Art

[0002] As a deep geostress testing method recommended by the International Society of Rock Mechanics in 1987, hydraulic fracturing has become the core means of deep hole geostress measurement by inducing rock fracture through high-pressure water injection and analyzing pressure response parameters (such as splitting pressure and re-tensioning pressure). Its standard equipment includes ground pipeline control system, high-pressure water pump, in-hole push-pull valve, upper and lower packers and fracturing flower pipes. The test process follows the standardized operation of "packer expansion-test section pressurization-data collection-equipment recovery".

[0003] However, under special hydrogeological conditions, especially when the borehole is located in an exploration flat cave, a low-elevation area in a river valley, or there is a pressurized water layer, the water level in the hole is higher than the hole mouth, causing water gushing, which will cause the following problems: 1. Failure of lowering the packer: The upward thrust generated by the gushing water exceeds the weight of the equipment, resulting in the packer being unable to reach the predetermined depth; 2. The push-pull valve is out of control: The continuous water gushing pressure forces the push-pull valve to a non-designed state (compression state), blocking the water injection channel required for the expansion of the packer, causing the test process to be interrupted.

[0004] In view of the above technical problems, there is an urgent need for a measuring device that can be freely lowered in a water-gushing borehole and ensure the controllability of the control valve under the action of high-pressure water. Summary of the invention

[0005] The purpose of the present invention is to provide a hydraulic fracturing ground stress measuring device to solve the technical problem in the prior art that when water gushes in the borehole, the measuring device cannot be lowered by its own weight, and at the same time, the continuous pressure of the gushing water will cause the push-pull valve to be in a non-designed state, thereby blocking the test process. To achieve the above purpose, the present invention proposes a hydraulic fracturing ground stress measuring device, and the specific scheme is as follows:

[0006] A hydraulic fracturing ground stress measuring device comprises: a water inlet module, a control valve, a sealing module and a water valve which are connected in sequence;

[0007] The water inlet module is in communication with the top of the control valve;

[0008] The control valve is provided with a fluid switching component for switching the fluid channel to achieve the switching of the water discharge and water injection paths;

[0009] The control valve is provided with a first channel and a second channel at the bottom; the first channel runs through the test section of the isolation module and is connected to the water-passing valve, and is used to discharge the gushing water out of the control valve under the gushing condition or to inject water into the test section under the water injection condition;

[0010] The second channel injects water into the two groups of expandable packers of the isolation module to expand them to form the test section;

[0011] The test section is used to withstand high-pressure water under water injection conditions to generate rock fractures, and to monitor water pressure data in real time through pressure sensors to calculate ground stress parameters;

[0012] An openable and closable cover plate is provided at the bottom of the water-passing valve and is connected to the first channel and the second channel. The cover plate is opened under water gushing conditions or closed under water filling conditions.

[0013] Preferably, the fluid switching assembly comprises: a compartment structure, a first fluid switching module and a second fluid switching module;

[0014] The compartment structure divides the interior of the valve body of the control valve into a plurality of compartments for allocating fluid paths;

[0015] The first fluid switching module is used to control the water injection path between the second channel and the packer, or the water injection path between the water inlet module and the test section;

[0016] The second fluid switching module is used to control a drainage path connecting the first channel to the drain trough, or a water injection path connecting the first channel to the test section.

[0017] Preferably, the compartment structure specifically includes: an upper partition, a middle partition and a lower partition;

[0018] The upper partition, the middle partition and the lower partition separate the valve body into a first bin body, a second bin body, a third bin body and a fourth bin body from top to bottom;

[0019] The first bin body is communicated with the fourth bin body through a valve wall hole, the second bin body is communicated with the second channel, and a drain groove is provided on a side wall of the third bin body.

[0020] Preferably, the first fluid switching module comprises: a first hollow valve stem, a first elastic member and a first through hole;

[0021] The first end of the first hollow valve stem is communicated with the water inlet module, and the second end thereof slides through the first bin body and the second bin body;

[0022] The first elastic member connects the middle diaphragm and the second end of the first hollow valve stem;

[0023] The first through hole is arranged on the side wall of the first hollow valve stem, and is used to switch to the second chamber body or the first chamber body under the action of the first elastic member, so as to connect the second channel with the packer or the water inlet module with the test section.

[0024] Preferably, the second fluid switching module comprises: a second hollow valve stem, a second elastic member, a second through hole and a third through hole;

[0025] The first end of the second hollow valve stem is communicated with the first channel, and the second end thereof slides through the third chamber body and the fourth chamber body;

[0026] The second elastic member connects the middle diaphragm and the second end of the second hollow valve stem;

[0027] The second through hole and the third through hole are axially arranged on the side wall of the second hollow valve stem; the second through hole is used to switch to the third chamber body under the action of the second elastic member to conduct the first channel and the drain groove;

[0028] The third through hole is used to switch to the fourth chamber under the action of the second elastic member to connect the first channel and the test section.

[0029] Preferably, the water valve comprises: a high-pressure water drive assembly and a water discharge channel;

[0030] The top of the water valve is in communication with the first channel;

[0031] The high-pressure water driving assembly is in communication with the second channel and is used to control the closing of the cover plate by high-pressure water;

[0032] The drainage channel is connected to the first channel and the water inlet at the bottom of the water valve, and is used to guide the gushing water in the drilled hole into the first channel for upward drainage when the gushing water impacts the open cover plate.

[0033] Preferably, the high-pressure water drive assembly comprises an axial hydraulic rod and a pull rod;

[0034] One end of the axial hydraulic rod is communicated with the second channel, and the other end is hinged to the cover plate via the pull rod;

[0035] When the high-pressure water pushes the axial hydraulic rod, the pull rod drives the cover plate to close to seal the water inlet.

[0036] Preferably, it also includes a filter;

[0037] The filter is arranged between the water inlet module and the control valve, and is used for filtering high-pressure water.

[0038] Preferably, at least two levels of detachable filter cups are provided in the filter.

[0039] Preferably, the water inlet module includes a high-pressure water pump and a drill rod;

[0040] The high-pressure water pump is in communication with the drill pipe;

[0041] The drill pipe is communicated with the control valve for providing high-pressure water to the control valve.

[0042] Beneficial effects: (1) The present invention can discharge the gushing water in the borehole through the water valve and the control valve, thereby solving the problem that the equipment cannot be lowered normally due to the gushing water in the borehole.

[0043] (2) The filter proposed by the present invention can filter impurities in high-pressure water, thereby preventing the impurities in the high-pressure water from clogging the control valve and the lower device. The filter is also easy to disassemble and rinse, and is quick and convenient to use.

[0044] (3) The working principle of the control valve proposed by the present invention is different from that of the conventional push-pull valve, which can avoid the problem that the conventional push-pull valve cannot open under the upward force of the water pressure in the hole. The control valve is not affected by the lower pressure water, and the controllability is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a schematic diagram of the overall structure of the measuring device in an embodiment of the present invention;

[0046] Figure 2 Schematic diagram of the control valve structure in an embodiment of the present invention, wherein (a) is a front view of the control valve, and (b) is a longitudinal cross-sectional view of the control valve;

[0047] Figure 3 The longitudinal cross-sectional views of the control valve in two states according to the embodiment of the present invention, wherein (c) is a cross-sectional view of the control valve in a natural state, and (d) is a cross-sectional view of the control valve in a stretched state;

[0048] Figure 4 A longitudinal cross-sectional view of a water valve in an embodiment of the present invention;

[0049] Figure 5 are longitudinal cross-sectional views of the water valve in two states according to an embodiment of the present invention, wherein (e) is a cross-sectional view of the water valve in a state where the cover is open, and (f) is a cross-sectional view of the water valve in a sealed state;

[0050] Figure 6 It is a longitudinal cross-sectional view of the filter in the embodiment of the present invention.

[0051] In the figure: 1. high-pressure water pump; 2. first high-pressure water pipe; 3. sensor and ground pipeline control system; 4. data acquisition instrument; 5. drilling tower; 6. handle; 7. top joint; 8. drilling rig; 9. test drilling hole; 10. drill rod; 11. filter; 1101. shell; 1102. threaded thread; 1103. upper filter cup; 1104. middle filter cup; 1105. lower filter cup; 1106. large water filter hole; 1107. middle water filter hole; 1108. small water filter hole; 12. control valve; 1201. upper partition; 1202. middle partition; 1203. lower partition; 1204. valve bottom interface; 1205. drain trough; 1206. first middle Hollow valve stem; 1207, first spring; 1208, first through hole; 1209, first water-stop pad; 1210, second hollow valve stem; 1211, second spring; 1212, second through hole; 1213, third through hole; 1214, second water-stop pad; 13, packer; 14, hollow connecting rod; 15, water-permeable hole; 16, second high-pressure water pipe; 17, water-passing valve; 1701, high-pressure water pipe interface; 1702, water inlet channel; 1703, third high-pressure water pipe; 1704, crossbeam; 1705, axial hydraulic rod; 1706, pull rod; 1707, cover plate; 1708, third spring; 1709, water inlet; 1710, water-stop pad. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific implementation methods. It should be understood that the specific implementation methods described here are only used to explain the present invention and do not limit the scope of protection of the present invention.

[0053] A hydraulic fracturing ground stress measuring device comprises: a water inlet module, a control valve 12, a sealing module and a water valve 17 which are connected in sequence;

[0054] The water inlet module is connected to the top of the control valve 12;

[0055] A fluid switching component is provided in the control valve 12 for switching the fluid channel to realize the switching of the water discharge and water injection paths;

[0056] The control valve 12 is provided with a first channel and a second channel at the bottom;

[0057] The first channel runs through the test section of the isolation module and is connected to the water valve 17, which is used to discharge the gushing water out of the control valve 12 under the water gushing condition or to inject water into the test section under the water injection condition;

[0058] The second channel injects water into the two groups of expandable packers 13 of the isolation module to expand them to form a test section;

[0059] The test section is used to withstand high-pressure water under water injection conditions to generate rock fractures, and monitor water pressure data in real time through pressure sensors to calculate ground stress parameters;

[0060] An openable and closable cover plate 1707 is provided at the bottom of the water valve 17 and is connected to the first channel and the second channel. The cover plate 1707 is opened under water gushing conditions or closed under water filling conditions.

[0061] like Figure 1 As shown, in addition to the underground measuring device, the present invention also includes surface equipment, specifically including sensors (including pressure sensors and flow sensors), ground pipeline control system, data acquisition instrument 4, drilling tower 5, handle 6 and top joint 7. The ground pipeline control system is used to control the delivery of high-pressure water source; the data acquisition instrument 4 is responsible for receiving and recording the data transmitted by the sensor; the drilling tower 5 is used in conjunction with the drilling rig 8 to lift and lower the water inlet module and the entire measuring device; the handle 6 is connected to the top joint 7 of the measuring device to facilitate lifting or lowering the device; the top joint 7 is connected to the handle 6 and the water inlet module to ensure the smooth input of high-pressure water. When in use, the test borehole 9 to be tested is first drilled out by the drilling rig 8 and the drilling tower 5. Then, the drilling tower 5 is used to lift or lower the measuring device to a specified position in the test borehole 9. Next, the high-pressure water pump 1 is started to provide high-pressure water to the control valve 12 through the drill rod 10. According to the test requirements, the fluid channel is switched by the fluid switching component in the control valve 12 to achieve water discharge or water injection operation. Under water injection conditions, the packer 13 expands and closes to form a test section, and then high-pressure water is injected into the test section to generate rock fractures. At the same time, the water pressure data is monitored in real time by the pressure sensor, and the ground stress parameters are finally calculated. It should be noted that the first channel at the bottom of the control valve 12 is specifically a hollow connecting rod 14, and the second channel is specifically a second high-pressure water pipe 16, and the hollow connecting rod 14 is provided with a water-permeable hole 15 at the position of the test section, which is used to inject the high-pressure water in the rod into the test section.

[0062] In the embodiment of the present invention, the water inlet module includes a high-pressure water pump 1 and a drill rod 10;

[0063] The high-pressure water pump 1 is connected to the drill pipe 10;

[0064] The drill pipe 10 is in communication with the control valve 12 for providing high-pressure water to the control valve 12 .

[0065] In this embodiment, the high-pressure water pump 1 is used to provide a high-pressure water source for the test. One end of the drill rod 10 is connected to the control valve 12, and the other end is connected to the high-pressure water pump 1 through the first high-pressure water pipe 2. The drill rod 10 serves as a flow channel for high-pressure water to provide high-pressure water to the control valve 12. The length of the drill rod 10 is determined according to the measurement depth.

[0066] Further, the fluid switching assembly includes: a compartment structure, a first fluid switching module and a second fluid switching module;

[0067] The compartment structure divides the interior of the valve body of the control valve 12 into multiple compartments for allocating fluid paths;

[0068] The first fluid switching module is used to control the water injection path between the second channel and the packer 13, or the water injection path between the water inlet module and the test section;

[0069] The second fluid switching module is used to control the drainage path connecting the first channel and the drain tank 1205, or the water injection path connecting the first channel and the test section.

[0070] Specifically, in the hydraulic fracturing ground stress measurement device of the present invention, the fluid switching assembly is responsible for switching the fluid path to meet the different requirements of water discharge and water injection operations. The fluid switching assembly is mainly composed of a compartment structure, a first fluid switching module and a second fluid switching module.

[0071] The compartment structure is designed inside the valve body of the control valve 12, dividing the valve body into multiple independent compartments. These compartments each undertake different fluid path allocation tasks to ensure the orderly flow of fluid in the control valve 12. It can effectively avoid the intersection and interference of fluid paths and improve the accuracy and reliability of fluid switching. The first fluid switching module is a key component for controlling the flow of fluid to the packer 13 or the test section. When it is necessary to inject water into the packer 13 to form a test section, the first fluid switching module will conduct the water injection path of the second channel and the packer 13, so that high-pressure water can be smoothly injected into the packer 13 and expand it. When it is necessary to inject water into the test section for hydraulic fracturing testing, the first fluid switching module will switch to the water injection path of the water inlet module and the test section to ensure that high-pressure water can be accurately delivered to the test section. The second fluid switching module is responsible for controlling the fluid flow direction of the first channel. Under the water gushing condition, in order to smoothly discharge the gushing water from the outside of the control valve 12, the second fluid switching module will conduct the drainage path of the first channel and the drain trough 1205. Under water injection conditions, in order to prevent leakage of high-pressure water, the second fluid switching module will close the drainage path and connect the water injection path between the first channel and the test section to ensure that high-pressure water can smoothly enter the test section for hydraulic fracturing testing.

[0072] The fluid switching assembly enables the hydraulic fracturing ground stress measurement device of the present invention to flexibly switch the fluid path to meet the different requirements of water discharge and water injection operations. At the same time, by precisely controlling the fluid flow direction and flow rate, the accuracy and reliability of the test results can be ensured.

[0073] The compartment structure of the embodiment of the present invention specifically includes: an upper partition 1201, a middle partition 1202 and a lower partition 1203;

[0074] The upper partition 1201, the middle partition 1202 and the lower partition 1203 separate the valve body into a first bin body, a second bin body, a third bin body and a fourth bin body from top to bottom;

[0075] The first bin body is connected to the fourth bin body through a valve wall hole, the second bin body is connected to the second channel, and a drain groove 1205 is provided on the side wall of the third bin body.

[0076] Specifically, in this embodiment, the second bin is specifically connected to the valve bottom interface 1204 at the bottom of the control valve 12, and the valve bottom interface 1204 is connected to the second channel. In this embodiment, the second channel is the second high-pressure water pipe 16. The side wall of the third bin is provided with a drain groove 1205, which is used to discharge the gushing water outside the control valve 12 under the gushing condition.

[0077] The first fluid switching module of the embodiment of the present invention comprises: a first hollow valve stem 1206, a first elastic member and a first through hole 1208;

[0078] The first end of the first hollow valve stem 1206 is connected to the water inlet module, and the second end thereof slides through the first compartment body and the second compartment body;

[0079] The first elastic member connects the middle partition plate 1202 and the second end of the first hollow valve stem 1206;

[0080] The first through hole 1208 is provided on the side wall of the first hollow valve stem 1206, and is used to switch to the second chamber or the first chamber under the action of the first elastic member, so as to connect the second channel with the packer 13 or the water inlet module with the test section.

[0081] The second fluid switching module of the embodiment of the present invention comprises: a second hollow valve stem 1210, a second elastic member, a second through hole 1212 and a third through hole 1213;

[0082] The first end of the second hollow valve stem 1210 is communicated with the first channel, and the second end thereof slides through the third chamber body and the fourth chamber body;

[0083] The second elastic member connects the middle partition plate 1202 and the second end of the second hollow valve stem 1210;

[0084] The second through hole 1212 and the third through hole 1213 are axially arranged on the side wall of the second hollow valve stem 1210; the second through hole 1212 is used to switch to the third chamber under the action of the second elastic member to conduct the first channel and the drain groove 1205;

[0085] The third through hole 1213 is used to switch to the fourth chamber under the action of the second elastic member to connect the first channel and the test section.

[0086] Specifically, Figure 2-Figure 3As shown, in the present invention, the first elastic member and the second elastic member are both springs, which are recorded as the first spring 1207 and the second spring 1211. The first spring 1207 and the second spring 1211 are both in a contracted state in the natural state. At this time, the state of the control valve 12 is recorded as the natural state. On the contrary, when the first spring 1207 and the second spring 1211 are in a stretched state, the state of the control valve 12 is recorded as the stretched state. When the control valve 12 is in the natural state, the first fluid switching module and the second fluid switching module connect the first channel with the drain trough 1205, and also connect the second channel with the packer 13, so as to realize the expansion of the packer 13 in the stage of lowering the measuring device for water discharge and measurement preparation. When the control valve 12 is in a stretched state, the first fluid switching module connects the water inlet module with the first bin body, and the second fluid switching module connects the fourth bin body with the first channel, so as to realize the connection of the water injection path of the test section.

[0087] In this embodiment, the first hollow valve stem 1206 and the second hollow valve stem 1210 are both designed as bolt-shaped rod bodies with hollow structures, and their second ends are designed to be protruding in order to prevent them from exceeding a predetermined travel range when sliding inside the control valve 12. Specifically, the protruding end of the first hollow valve stem 1206 is equipped with a first water stop pad 1209 at a position adjacent to the upper partition 1201, and the protruding end of the second hollow valve stem 1210 is provided with a second water stop pad 1214 at a position adjacent to the lower partition 1203. The first water stop pad 1209 and the second water stop pad 1214 are used to ensure the sealing of the control valve 12.

[0088] It should be noted that if Figure 2 As shown, the second through hole 1212 and the third through hole 1213 are respectively arranged along the axial direction of the second hollow valve stem 1210. The sliding position of the second hollow valve stem 1210 determines the connection state of these through holes. Specifically: when the control valve 12 is in a natural state, the second through hole 1212 is connected to the inside of the third chamber body, allowing water to pass through the channel; when the control valve 12 is in a stretched state, the second through hole 1212 will be blocked by the lower partition 1203, thereby preventing the flow of fluid.

[0089] In this embodiment, the third through hole 1213 is designed so that it always remains connected to the fourth bin body during the sliding process of the second hollow valve stem 1210. This is because, when the control valve 12 is in a natural state, preparations for water discharge or water injection of the packer 13 are usually carried out. At this time, the first bin body is in a closed state and does not participate in the current fluid path. Therefore, the fluid state in the fourth bin body, which is connected to the first bin body through the valve wall hole, has no direct effect on the current fluid path selection. Based on this principle, the third through hole 1213 is designed to remain connected to the fourth bin body throughout the entire range of motion of the control valve 12, including when the control valve 12 is in a natural or stretched state. Of course, according to specific design requirements, the third through hole 1213 may also be blocked by the lower partition 1203 when the control valve 12 is in the natural state.

[0090] When the control valve 12 is in a natural state, the first through hole 1208 is located in the second compartment body, and the second through hole 1212 is located in the third compartment body. At this time, the measuring device is lowered, and the gushing water enters the third compartment body through the water valve 17 and the first channel connected to the water valve 17, and then is discharged from the control valve 12 through the drain groove 1205 on the side wall of the third compartment body, thereby realizing the conduction and drainage of the gushing water in the borehole, and solving the problem that the measuring device cannot be lowered normally due to the gushing water in the hole.

[0091] When entering the measurement preparation stage, that is, the measuring device is lowered to the preset position, the water discharge ends, and the high-pressure water pump 1 supplies water to the control valve 12. The water flows into the second chamber through the first through hole 1208. Since the second chamber is connected to the second high-pressure water pipe 16 through the valve bottom interface 1204, the water flows into the second high-pressure water pipe 16, supplies water to the isolation device 13 to expand it to form a test section, and at the same time, the water flows into the water valve 17 and drives the cover plate 1707 of the water valve 17 to close.

[0092] When the measurement preparation stage is completed, that is, when the expansion of the packer 13 meets the preset requirements, the drill pipe 10 is lifted to put the control valve 12 in a stretched state. At this time, the first through hole 1208 is located in the first compartment, the second through hole 1212 is closed, and the third through hole 1213 is located in the fourth compartment. The high-pressure water pumped out by the high-pressure water pump 1 enters the first compartment and the fourth compartment of the control valve 12 through the first hollow valve stem 1206 and the first through hole 1208, and then enters the second hollow valve stem 1210 through the third through hole 1213 and the first channel into the test section, thereby injecting high-pressure water into the test section for ground stress measurement.

[0093] The water valve 17 of the embodiment of the present invention comprises: a high-pressure water driving component and a water discharge channel;

[0094] The top of the water valve 17 is connected to the first channel;

[0095] The high-pressure water driving assembly is in communication with the second channel and is used to control the closing of the cover plate 1707 by high-pressure water;

[0096] The drainage channel is connected to the first channel and the water inlet 1709 at the bottom of the water valve 17, and is used to guide the gushing water in the borehole into the first channel for upward drainage when the gushing water impacts the open cover plate 1707.

[0097] In this embodiment, the high-pressure water drive assembly is connected to the second channel and is used to control the bottom cover plate 1707 of the water valve 17 to close, so that it and the packer 13 form a closed water storage space to ensure the stability of the test section.

[0098] The high-pressure water drive assembly of the embodiment of the present invention includes an axial hydraulic rod 1705 and a pull rod 1706;

[0099] One end of the axial hydraulic rod 1705 is connected to the second channel, and the other end is hinged to the cover plate 1707 via the pull rod 1706;

[0100] When the high-pressure water pushes the axial hydraulic rod 1705 , the pull rod 1706 drives the cover plate 1707 to close, so as to seal the water inlet 1709 .

[0101] Specifically, in this embodiment, Figure 4 As shown, the cover plate 1707 includes two hinged semicircular lower cover plates 1707, and a water stop gasket 1710 is provided at the end of the cover plate 1707. The two cover plates 1707 are connected by a third spring 1708, so that the cover plates 1707 are in an open state under normal conditions. Of course, in other embodiments, the third spring 1708 may not be used, and the cover plates 1707 are pushed open by the force of the gushing water. The axial hydraulic rod 1705 is fixed on the crossbeam 1704 in the water valve 17, and one end of it is connected to the second high-pressure water pipe 16 through the third high-pressure water pipe 1703, and the other end is hinged to the lower cover plate 1707 through the pull rod 1706; Figure 4 and Figure 5 As shown, specifically, a water inlet channel 1702 is provided at the top of the water valve 17, and a high-pressure water pipe interface 1701 is provided at one side of the outer wall of the water valve 17. The high-pressure water pipe interface 1701 is communicated with the second high-pressure water pipe 16, and the water inlet channel 1702 is communicated with the third high-pressure water pipe 1703 at one side of the inner wall of the water valve 17. When the third high-pressure water pipe 1703 is injected with high-pressure water, the axial hydraulic rod 1705 pushes the pull rod 1706 to close the cover plate 1707 to close the water inlet 1709; when the high-pressure water is removed, the third spring 1708 resets the cover plate 1707 to the open state, and the water inlet 1709 is connected to the drain channel.

[0102] The embodiment of the present invention further includes a filter 11;

[0103] The filter 11 is disposed between the water inlet module and the control valve 12 and is used for filtering the high-pressure water.

[0104] Specifically, at least two levels of detachable filter cups are arranged in the filter 11 .

[0105] The filter 11 is arranged between the water inlet module and the control valve 12. Figure 6 As shown, specifically, its top is connected to the drill rod 10 through a threaded thread 1102, and its bottom is connected to the control valve 12; a three-level detachable filter cup is provided in the filter 11 for graded filtration of high-pressure water. The outer shell 1101 of the filter 11 is cylindrical, and its wall thickness is gradually thickened in a step-like manner from top to bottom. The wall thickness of the outer shell 1101 is divided into three levels from top to bottom, corresponding to the installation positions of the upper, middle and lower filter cups, respectively, and the wall thickness of each level increases by 2mm-3mm. Specifically, the filter cup includes an upper filter cup 1103, a middle filter cup 1104 and a lower filter cup 1105 arranged from top to bottom, and the three are detachably connected to the outer shell 1101 by snap-fit ​​or threading; the aperture of the water filter hole of each filter cup decreases step by step from top to bottom, forming a multi-stage filtration structure. The water filtering hole of the upper filter cup 1103 is a large water filtering hole 1106 ; the water filtering hole of the middle filter cup 1104 is a medium water filtering hole 1107 ; and the water filtering hole of the lower filter cup 1105 is a small water filtering hole 1108 .

[0106] The working principle and use process of the measuring device of the present invention are as follows:

[0107] First, after the test drilling 9 is completed, a suitable measurement depth is selected and the length of the drill rod 10 is determined to ensure that the test can be carried out on the predetermined geological layer.

[0108] Subsequently, the water valve 17, the second high-pressure water pipe 16, the packer 13, the control valve 12, the filter 11, and the drill rod 10 are connected in sequence through the handle 6 and lowered into the hole. Different lengths of the drill rod 10 can be used for different measuring depths until the hole is lowered to the specified depth. During the lowering process, the bottom cover plate 1707 of the water valve 17 is in an open state, and the gushing water enters the control valve 12 through the water inlet 1709, and then enters the hollow connecting rod 14 as the first channel and then enters the control valve 12. In the control valve 12, the water passes through the second hollow valve stem 1210, the second through hole 1212, and the drain groove 1205 and then exits the control valve 12, ensuring that the device can be smoothly lowered to the specified depth.

[0109] After the device is lowered to the predetermined measurement depth, the surface equipment is connected: top joint 7, sensor and surface pipeline control system 3, data acquisition instrument 4, first high-pressure water pipe 2, high-pressure water pump 1. After the connection is completed, the high-pressure water pump 1 is turned on, the surface pipeline control system is adjusted, and high-pressure water is pumped into the underground measurement device (the control valve 12 is in a natural state). The high-pressure water enters the control valve 12 through the drill pipe 10 and the filter 11, and enters the second chamber of the control valve 12 through the first hollow valve stem 1206 and the first through hole 1208. The second chamber is connected to the valve bottom interface 1204. After passing through the valve bottom interface 1204, it enters the packer 13 and the water valve 17 in sequence through the second high-pressure water pipe 16. The packer 13 expands under the action of high-pressure water, and the two packers 13 are closely attached to the borehole wall, forming a closed test section between them. When high-pressure water is pumped into the water valve 17, the axial hydraulic rod 1705 moves downward, pushing the pull rod 1706, driving the lower cover plate 1707 downward until it contacts the inner wall. At this time, the cover plate 1707 is closed and the water valve 17 is in a sealed state.

[0110] Next, the drill pipe 10 is slightly lifted by the handle 6 and the top joint 7. Since the expanded packer 13 fits tightly against the borehole wall, the equipment below the control valve 12 is fixed. The lifting causes the first spring 1207 and the second spring 1211 inside the control valve 12 to be in a stretched state. At this time, the control valve 12 is in a stretched state, and then high-pressure water is pumped in. It passes through the first hollow valve stem 1206 and the first through hole 1208 and enters the first chamber of the control valve 12. The first chamber is connected to the fourth chamber, and the high-pressure water enters the fourth chamber, and then enters the second hollow valve stem 1210 through the third through hole 1213, and then enters the hollow connecting rod 14 as the second channel. Since the water valve 17 is sealed at this time, the high-pressure water enters the test section from the water permeable hole 15 of the connecting rod.

[0111] The test section is pressurized with a high-pressure water pump 1, and the pressure-flow-time curve is collected through the ground pipeline control system and the ground data acquisition system. Parameters such as splitting pressure, reopening pressure, and closing pressure are selected on the curve to measure the ground stress.

[0112] After the measurement is completed, the high-pressure water pump 1 is turned off, and the high-pressure water in the test section flows back. After the test section is depressurized, the drill pipe 10 is lowered through the handle 6 and the top joint 7. At this time, the first spring 1207 and the second spring 1211 inside the control valve 12 shrink to put it in a natural state. The high-pressure water is discharged from the water valve 17 and the packer 13 to the control valve 12, enters the second chamber through the valve bottom interface 1204, and is discharged to the drill pipe 10 through the first through hole 1208, so that the packer 13 is depressurized.

[0113] After the packer 13 is depressurized, it returns to its original state, and after the water valve 17 is depressurized, its lower cover plate 1707 is opened. The equipment can move freely, repeat the above, and continue to test other depths.

[0114] In the water-gushing borehole, the present invention can discharge the water gushing in the hole through the water valve 17, the hollow connecting rod 14, and the control valve 12, thereby solving the problem that the equipment cannot be lowered normally due to the water gushing in the hole. The filter 11 proposed by the present invention can filter impurities in high-pressure water, prevent the problem of impurities in high-pressure water clogging the control valve 12 and the lower device, and is easy to disassemble and flush, and is convenient and quick to use. The working principle of the control valve 12 proposed by the present invention is different from that of the conventional push-pull valve, and can avoid the problem that the conventional push-pull valve cannot open under the upward force of the water pressure in the hole. The control valve 12 is not affected by the lower pressure water, and the controllability is greatly improved. The present invention can not only be used for water-gushing boreholes, but is also applicable to conventional boreholes. When the water level in the borehole is deep, there is no need to add a separate pressure relief device, and it has strong applicability.

[0115] The above are only several embodiments of the present invention and are not intended to limit the present invention in any form. Although the present invention is disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the profession, without departing from the scope of the technical solution of the present invention, using the above disclosed technical content to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A hydraulic fracturing ground stress measurement device, characterized in that: include: A water inlet module, a control valve, a sealing module and a water valve connected in sequence; The water inlet module is in communication with the top of the control valve; The control valve is provided with a fluid switching component for switching the fluid channel to achieve the switching of the water discharge and water injection paths; The bottom of the control valve is provided with a first channel and a second channel; The first channel runs through the test section of the isolation module and is connected to the water-passing valve, and is used to discharge gushing water out of the control valve under water gushing conditions or to inject water into the test section under water injection conditions; The second channel injects water into the two groups of expandable packers of the isolation module to expand them to form the test section; The test section is used to withstand high-pressure water under water injection conditions to generate rock fractures, and to monitor water pressure data in real time through pressure sensors to calculate ground stress parameters; An openable and closable cover plate is provided at the bottom of the water-passing valve and is connected to the first channel and the second channel. The cover plate is opened under water gushing conditions or closed under water filling conditions.

2. The hydraulic fracturing ground stress measuring device according to claim 1, characterized in that: The fluid switching assembly includes: a compartment structure, a first fluid switching module and a second fluid switching module; The compartment structure divides the interior of the valve body of the control valve into a plurality of compartments for allocating fluid paths; The first fluid switching module is used to control the water injection path between the second channel and the packer, or the water injection path between the water inlet module and the test section; The second fluid switching module is used to control a drainage path connecting the first channel to the drain trough, or a water injection path connecting the first channel to the test section.

3. The hydraulic fracturing ground stress measuring device according to claim 2, characterized in that: The compartment structure specifically includes: an upper partition, a middle partition and a lower partition; The upper partition, the middle partition and the lower partition separate the valve body into a first bin body, a second bin body, a third bin body and a fourth bin body from top to bottom; The first bin body is communicated with the fourth bin body through a valve wall hole, the second bin body is communicated with the second channel, and a drain groove is provided on a side wall of the third bin body.

4. The hydraulic fracturing ground stress measuring device according to claim 3, characterized in that: The first fluid switching module comprises: a first hollow valve stem, a first elastic member and a first through hole; The first end of the first hollow valve stem is communicated with the water inlet module, and the second end thereof slides through the first bin body and the second bin body; The first elastic member connects the middle diaphragm and the second end of the first hollow valve stem; The first through hole is arranged on the side wall of the first hollow valve stem, and is used to switch to the second chamber body or the first chamber body under the action of the first elastic member, so as to connect the second channel with the packer or the water inlet module with the test section.

5. The hydraulic fracturing ground stress measuring device according to claim 3, characterized in that: The second fluid switching module includes: a second hollow valve stem, a second elastic member, a second through hole and a third through hole; The first end of the second hollow valve stem is communicated with the first channel, and the second end thereof slides through the third chamber body and the fourth chamber body; The second elastic member connects the middle diaphragm and the second end of the second hollow valve stem; The second through hole and the third through hole are axially arranged on the side wall of the second hollow valve stem; The second through hole is used to switch to the third chamber under the action of the second elastic member to connect the first channel and the drain groove; The third through hole is used to switch to the fourth chamber under the action of the second elastic member to connect the first channel and the test section.

6. The hydraulic fracturing ground stress measuring device according to claim 1, characterized in that: The water valve comprises: a high-pressure water drive assembly and a water discharge channel; The top of the water valve is in communication with the first channel; The high-pressure water driving assembly is in communication with the second channel and is used to control the closing of the cover plate by high-pressure water; The drainage channel is connected to the first channel and the water inlet at the bottom of the water valve, and is used to guide the gushing water in the drilled hole into the first channel for upward drainage when the gushing water impacts the open cover plate.

7. The hydraulic fracturing ground stress measuring device according to claim 6, characterized in that: The high-pressure water drive assembly includes an axial hydraulic rod and a pull rod; One end of the axial hydraulic rod is communicated with the second channel, and the other end is hinged to the cover plate via the pull rod; When the high-pressure water pushes the axial hydraulic rod, the pull rod drives the cover plate to close to seal the water inlet.

8. The hydraulic fracturing ground stress measuring device according to claim 1, characterized in that: Also includes filters; The filter is arranged between the water inlet module and the control valve, and is used for filtering high-pressure water.

9. The hydraulic fracturing ground stress measuring device according to claim 8, characterized in that: At least two levels of detachable filter cups are arranged in the filter.

10. The hydraulic fracturing ground stress measuring device according to claim 1, characterized in that: The water inlet module includes a high-pressure water pump and a drill pipe; The high-pressure water pump is in communication with the drill pipe; The drill pipe is communicated with the control valve for providing high-pressure water to the control valve.

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