Pressure water device for freely adjusting length of downhole test section and method of use thereof

Abstract

The application discloses a pressure water device for freely adjusting the length of a test section in a well and a use method thereof. The device comprises a drill pipe, a three-channel switch valve connected with the drill pipe, a first channel, a second channel and a third channel of the three-channel switch valve, and the three-channel switch valve is switched in the process of lifting the drill pipe; an upper packer plug communicated with the first channel of the three-channel switch valve through a first pipeline; an extension rod with one end connected with the upper packer plug away from the drill pipe; a lower packer plug connected with the other end of the extension rod, a test section formed between the upper packer plug and the lower packer plug, and the length of the test section can be adjusted by adjusting the length of the extension rod; the test section is communicated with the second channel of the three-channel switch valve through a second pipeline, and the lower packer plug is communicated with the third channel of the three-channel switch valve through a third pipeline. The distance between the upper packer plug and the lower packer plug is adjusted by controlling the upper and lower packer plugs, so that the length of the test section is freely adjusted.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of civil engineering technology survey, and particularly relates to a pressure water device capable of freely adjusting the length of a test section in a well and a use method thereof. BACKGROUND

[0002] Water and hydropower projects have the characteristics of high water head and large buried depth of underground caverns. When surveying such projects, the permeation characteristics and permeation stability of the surrounding rock of the underground cavern under high internal water pressure need to be understood in detail. Such parameters are often obtained through on-site rock high-pressure water pressure test to provide data support for subsequent lining form selection and design of high internal water pressure diversion tunnels and high-pressure branch pipes.

[0003] High-pressure water pressure test is to isolate the rock mass of the drill hole to be tested by a high-pressure pipeline through a water stop device, generally a pair of rubber plugs, by pressing to expand the plugs, and then injecting high-pressure water flow into the isolated test rock mass through another pipeline to measure the real-time pressure and flow rate, so as to calculate the permeability coefficient of the test section rock mass. The traditional high-pressure water pressure test is a fixed test section length within a range of 3-6 m. In actual surveying, different test lengths often need to be replaced due to the influence of the geological conditions of the drill hole. The traditional method cannot adjust the test length underground, and the underground test device must be completely raised to the ground surface for replacement, which is time-consuming and laborious. Therefore, a pressure water device capable of freely and flexibly adjusting the length of the test section is needed to be developed. SUMMARY

[0004] An object of the present application is to provide a pressure water device capable of freely adjusting the length of a test section in a well, which can freely and flexibly adjust the length of the pressure water test section according to needs, and is convenient and fast to operate.

[0005] To solve the above technical problems, the present application adopts the following technical solutions:

[0006] A pressure water device capable of freely adjusting the length of a test section in a well, which is arranged in a drill hole during testing, comprises:

[0007] a drill rod;

[0008] a three-channel switching valve connected with the drill rod, the three-channel switching valve comprising a first channel, a second channel and a third channel, the three-channel switching valve being switched by the drill rod during lifting and lowering;

[0009] an upper sealing plug communicated with the first channel of the three-channel switching valve through a first pipeline;

[0010] a telescopic rod, one end of which is connected with the end of the upper sealing plug away from the drill rod;

[0011] A lower packer is connected with the other end of the telescopic rod, and a test section is formed between the upper packer and the lower packer, and the length of the test section is adjusted by adjusting the length of the telescopic rod.

[0012] The test section is communicated with the second passage of the three-way switching valve through a second pipeline, and the lower packer is communicated with the third passage of the three-way switching valve through a third pipeline.

[0013] Further, the three-way switching valve comprises a valve body and a valve core, wherein the valve core is connected with the drill rod, and displacement change between the valve core and the valve body forms the first passage, the second passage or the third passage, and the drill rod drives the valve core to move in the process of lifting, so that the three-way switching valve switches the passage.

[0014] Further, the valve body has an axial first through hole, and the first through hole is divided into a first sealing area, a second sealing area and a third sealing area from bottom to top along the axial direction, and the valve body further has a second through hole and a third through hole, wherein the second through hole is communicated with the second sealing area, and the third through hole is communicated with the third sealing area.

[0015] The valve core is arranged in the first through hole and can move along the axial direction, and the valve core has a passage, and the passage of the valve core is selectively communicated with the first sealing area, the second sealing area or the third sealing area by moving the valve core along the axial direction, when the passage of the valve core is communicated with the first sealing area, the first passage is formed, when the passage of the valve core is communicated with the second sealing area, the second passage is formed, and when the passage of the valve core is communicated with the third sealing area, the third passage is formed.

[0016] Further, the first sealing ring, the second sealing ring and the third sealing ring are arranged in the first through hole from bottom to top along the axial direction, the valve core is arranged in the first through hole through the first sealing ring, the second sealing ring and the third sealing ring, and the first sealing ring, the second sealing ring and the third sealing ring divide the first through hole into the first sealing area, the second sealing area, the third sealing area and a fourth sealing area.

[0017] Further, the valve core has a non-through axial hole and a through radial hole, the radial hole is communicated with the axial hole, when the drill rod drives the valve core to drop to the maximum stroke in the through hole, the radial hole is communicated with the first sealing area, and when the drill rod drives the valve core to lift to the maximum stroke, the radial hole is communicated with the third sealing area.

[0018] Further, a plurality of elastic sheets are arranged on the outer wall of the valve body along the circumferential direction, when the three-way switching valve is arranged in the borehole, the elastic sheets generate frictional resistance with the wall of the borehole in the process of lifting the drill rod, so that the valve core and the valve body generate relative movement and stroke.

[0019] Further, the three-way switching valve is connected with the high-pressure water pump through the drill rod.

[0020] Further, the water pressurizing device further comprises a pressure and flow monitoring device.

[0021] Further, the pressure and flow monitoring device comprises a pressure sensor, a flow sensor, a data acquisition device electrically connected with the pressure sensor and the flow sensor, and a data processing device electrically connected with the data acquisition device.

[0022] The pressure sensor is arranged at the orifice of the drill pipe, and the flow sensor is arranged at the water outlet of the high-pressure water pump.

[0023] Another object of the present application is to provide a method for using the water pressurizing device for freely determining the length of downhole test according to the above, comprising the following steps:

[0024] Step 1, after the water pressurizing device is placed at a predetermined depth in the borehole, the drill pipe is lifted, the three-way conversion valve is moved downward to the maximum stroke under the gravity of the upper and lower sealing plugs and the telescopic rod, the third passage is connected, water is injected into the third passage and pressurized to a predetermined value, the water is injected into the downhole sealing plug through the third passage and the third pipeline, the downhole sealing plug is expanded and tightly attached to the borehole wall under the action of water and pressure, and at this time, the lower end of the test section is sealed.

[0025] Step 2, the drill pipe is lowered until the first passage of the three-way conversion valve is connected, then the position of the upper sealing plug is adjusted to adjust the length of the telescopic rod to obtain a suitable test section length, water is injected into the first passage and pressurized to a predetermined value, the water is injected into the upper sealing plug through the first passage and the first pipeline, the upper sealing plug is expanded and tightly attached to the borehole wall under the action of water and pressure, and at this time, the upper end of the test section is sealed.

[0026] Step 3, the drill pipe is lifted until the second passage of the three-way conversion valve is connected, the water path leads to the test section, and at this time, the water pressure test is completed in the test section according to the requirements of the survey specification.

[0027] Step 4, after the water pressure test is completed, the drill pipe is lifted upward until the third passage is connected, the water in the downhole sealing plug is discharged through the third passage and the third pipeline until the downhole sealing plug is contracted and separated from the borehole wall.

[0028] Step 5, the drill pipe is lowered until the first passage of the three-way conversion valve is connected, the water in the upper sealing plug is discharged through the first passage and the first pipeline until the upper sealing plug is contracted and separated from the borehole wall, and at this time, the entire water pressurizing device is unsealed from the borehole and can freely move in the borehole.

[0029] Step 6, the water pressurizing device is moved to other positions and the length of the test section is adjusted as needed to perform the next test.

[0030] Wherein, the order of step 4 and step 5 can be interchanged.

[0031] Compared with the prior art, the present application has the beneficial effects that: the present application switches the water path according to the relative position between the valve core and the valve body, when the valve core is pulled up to the maximum stroke, the water path leads to the lower packer plug, when the valve core is compressed to the maximum stroke in the valve body, the water path leads to the upper plug, when the valve core is at the intermediate stroke, the water path leads to the test section, the present application adjusts the distance between the upper and lower packer plugs through asynchronous control of the upper and lower plugs, so as to realize the purpose of adjusting the length of the test section. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is a structure schematic diagram of the water pressurizing device of the embodiment of the present application.

[0033] Figure 2 It is a structure schematic diagram of the three-channel switching valve inside when the lower packer plug is connected of the embodiment of the present application.

[0034] Figure 3 It is a structure schematic diagram of the three-channel switching valve inside when the upper packer plug is connected of the embodiment of the present application.

[0035] Figure 4 It is a structure schematic diagram of the three-channel switching valve inside when the test section is connected of the embodiment of the present application. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described below with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0037] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0038] The present application will be further described below with specific embodiments, but not as a limitation of the present application.

[0039] As Figure 1As shown, the embodiment of the present application provides a pressure water device for freely adjusting the length of downhole test, which is arranged in the borehole during test and comprises a drill pipe 1, a three-way switching valve 2, an upper sealing plug 3, an extension pipe 4 and a lower sealing plug 5. The three-way switching valve 2 comprises a valve body 21 and a valve core 22, wherein the valve core 22 is connected with the drill pipe 1. The valve core 22 cooperates with the valve body 21 to form a first passage, a second passage and a third passage, and the drill pipe 1 drives the valve core 22 to move during lifting process so as to switch the passages of the three-way switching valve 2. Specifically, the valve body 21 has an axial first through hole 210, and a first sealing ring 211, a second sealing ring 212 and a third sealing ring 213 are sequentially and axially arranged from bottom to top in the first through hole 210, which divides the through hole into a first sealing area 214, a second sealing area 215, a third sealing area 216 and a fourth sealing area 217. In addition, a second through hole 218 and a third through hole 219 which are not communicated with each other are arranged on the side wall of the valve body 21, wherein the second through hole 218 is communicated with the second sealing area 215, and the third through hole 219 is communicated with the third sealing area 216. The valve core 22 is inserted into the first through hole 210 through the first sealing ring 211, the second sealing ring 212 and the third sealing ring 213, and the valve core 22 can move axially in the first through hole 210. A passage is arranged in the valve core 22, and the passage of the valve core 22 is selectively communicated with the first sealing area 214, the second sealing area 215 or the third sealing area 216 by moving the valve core 22 axially. When the passage of the valve core 22 is communicated with the first sealing area 214, the first passage is formed; when the passage of the valve core 22 is communicated with the second sealing area 215, the second passage is formed; and when the passage of the valve core 22 is communicated with the third sealing area 216, the third passage is formed. Specifically, an axial hole 220 which does not penetrate and a radial hole 221 which penetrates radially are arranged in the valve core 22, and the radial hole 221 is communicated with the axial hole 220. When the drill pipe 1 drives the valve core 22 to descend to the maximum stroke in the first through hole 210, the radial hole 221 is communicated with the first sealing area 214; and when the drill pipe 1 drives the valve core 22 to ascend to the maximum stroke, the radial hole 222 is communicated with the third sealing area 216. During test, a spring 6 is arranged outside the valve body, and when the three-way switching valve 2 is arranged in the borehole, the spring 6 generates friction resistance with the hole wall during the lifting process of the drill pipe 1, so as to facilitate the relative movement and stroke of the valve core 22 and the valve body 21.

[0040] The upper sealing plug 3 is communicated with the first sealing area 214 through the first pipe 7, and is located below the three-way switching valve 2. One end of the telescopic rod 4 is connected with the upper sealing plug 3 away from the drill pipe 1, and the other end of the telescopic rod 4 is connected with the lower sealing plug 5. The test section for the water pressure test is formed between the upper sealing plug 3 and the lower sealing plug 5. The length of the test section can be adjusted by adjusting the length of the telescopic rod 4. When the radial hole 221 on the valve core 22 is communicated with the second sealing area 215, the test section is communicated with the second through hole 218 and the second sealing area 215 through the second pipe 8. The lower sealing plug 5 is communicated with the third through hole 219 through the third pipe 9. In order to facilitate the pipe to work in the borehole, the first pipe 7, the second pipe 8 and the third pipe 9 are all made of rubber pipes.

[0041] The three-way switching valve 2 is also connected with a high-pressure water pump 14, which is used to pressurize the water injection in the borehole. In order to monitor the pressure of the water injection in the borehole in real time and obtain the pressure of the test section during the test, and at the same time obtain the water injection flow, the water pressure device further comprises a pressure and flow monitoring device. The pressure and flow monitoring device comprises a pressure sensor 10 arranged at the drill pipe 1 aperture, a flow sensor 15 arranged at the water outlet end of the high-pressure water pump 14, a data acquisition device 11 electrically connected with the pressure sensor 10 and the flow sensor 15, and a data processing device 12 electrically connected with the data acquisition device 11. The pressure sensor 10 collects the water injection pressure at the drill pipe aperture in real time and transmits it to the data acquisition device 11, while the flow sensor 15 collects the water outlet flow of the high-pressure water pump in real time and transmits it to the data acquisition device. The data acquisition device 11 receives the pressure signal transmitted by the pressure sensor 10 and the flow signal transmitted by the flow sensor 15 and transmits them to the data processing device 12. The data processing device 12 processes the pressure signal and the flow signal and displays them to the monitoring personnel. The monitoring personnel obtains the pressure information and the flow information and decides the subsequent related operation according to the pressure information and the flow information. In addition, in order to more conveniently read the pressure information at the drill pipe aperture, the pressure sensor 10 is also connected with a pressure gauge 13. The operator can directly obtain the pressure in the drill pipe aperture according to the pressure gauge 13.

[0042] When using the above water pressure device for freely adjusting the length of the downhole test, the following steps are included:

[0043] Step 1, after placing the above water pressure device in the borehole at a predetermined depth, such as Figure 2As shown, the drill pipe 1 is lifted, the valve body 21 of the three-way switching valve 2 is moved downward to the maximum stroke under the gravity of the upper and lower packers and the telescopic rod 4, at this time, the valve core 22 is lifted to the maximum stroke relative to the valve body 21, the channel on the valve core 22 is communicated with the third sealing area 216, that is, the third passage of the three-way switching valve 2 is connected, water is injected into the third passage of the three-way switching valve through the high-pressure water pump 14 and is pressurized to a predetermined pressure value, the water is injected into the lower packer 5 through the third passage and the third pipeline 9 in turn, the lower packer 5 is expanded and tightly attached to the borehole wall under the action of water and pressure, at this time, the lower end of the test section is sealed;

[0044] Step 2, see Figure 3 , the drill pipe 1 is lowered until the valve core 22 connected with the drill pipe 1 is pressed to the limit position in the valve body 21, at this time, the channel on the valve core 22 is communicated with the first sealing area 214, then the first passage of the three-way switching valve 2 is connected, the upper packer is moved to the length of the telescopic rod that meets the test requirements, so that

[0045] the length of the test section that meets the test requirements is obtained, water is injected into the first passage 5 of the three-way switching valve 2 through the high-pressure water pump 14 and is pressurized to a predetermined pressure value, the water is injected into the upper packer 3 through the first passage and the first pipeline 7, the upper packer 3 is expanded and tightly attached to the borehole wall under the action of water and pressure, at this time, the upper end of the test section is sealed;

[0046] Step 3, on the basis of step 2, the drill pipe 1 is lifted, as shown Figure 4 , the drill pipe drives the valve core 22 to rise to the channel on the valve core 22 being communicated with the second sealing area 215, the second passage of the three-way switching valve 2 is connected, the water path leads to the test section, at this time, the water pressure test is completed in the test section according to the requirements of the survey specification;

[0047] Step 4, after the water pressure test is completed, the drill pipe 1 is lifted upward to the maximum stroke (see Figure 2 ), at this time, the passage of the valve core 22 is communicated with the third sealing area 216, then the third passage is connected, the water in the lower packer 5 is pumped out through the third passage and the third pipeline 9 until the lower packer 5 shrinks and separates from the borehole wall;

[0048] Step 5, the drill pipe 1 is lowered until the channel on the valve core 22 connected with the drill pipe 1 is communicated with the first sealing area 214 (see Figure 3 ), then the first passage of the three-way switching valve 2 is connected, the water in the upper packer 3 is pumped out through the first passage and the first pipeline 7 until the upper packer 3 shrinks and separates from the borehole wall, at this time, the entire water pressure device is unsealed from the borehole and can move freely in the borehole;

[0049] Step 6, the water pressure device is moved to other positions and the length of the test section is adjusted as needed in order to

[0050] Proceed to next segment test;

[0051] 0wherein step 4 and step 5 can be interchanged in order.

[0052] The above merely preferred embodiments of the present application, and not therefore limit the embodiments and protection scope of the present application, for those skilled in the art, should be able to realize that any equivalent replacement and obvious changes made by the application description, the resulting scheme should be included within the scope of the present application.

Claims

1. A pressurized water device for freely adjusting the length of a test section in a well, said pressurized water device being arranged in a borehole during testing, characterized in that The utility model relates to a high-pressure water injection device for oil and gas well testing, comprising: a drill pipe; a three-channel switching valve connected with the drill pipe, the three-channel switching valve comprising a first channel, a second channel and a third channel, the three-channel switching valve switching the channels during the lifting of the drill pipe; an upper packer communicated with the first channel of the three-channel switching valve through a first pipe; an extension rod connected with one end of the upper packer away from the drill pipe; a lower packer connected with the other end of the extension rod, a test section being formed between the upper packer and the lower packer, the length of the test section being adjusted by adjusting the length of the extension rod; wherein the test section is communicated with the second channel of the three-channel switching valve through a second pipe, and the lower packer is communicated with the third channel of the three-channel switching valve through a third pipe; the three-channel switching valve comprises a valve body and a valve core, wherein the valve core is connected with the drill pipe, and displacement change between the valve core and the valve body forms the first channel, the second channel or the third channel, the valve core moving during the lifting of the drill pipe to switch the channels of the three-channel switching valve; a plurality of elastic sheets are installed on the outer wall of the valve body in the circumferential direction, and when the three-channel switching valve is placed in a borehole, frictional resistance is generated between the elastic sheets and the borehole wall during the lifting of the drill pipe to facilitate the relative movement and stroke between the valve core and the valve body.

2. The pressurized water device for freely adjusting the length of a test section in a well according to claim 1, characterized in that, the valve body has an axially-through first through-hole, and the first through-hole is divided into a first sealing area, a second sealing area and a third sealing area from bottom to top along the axial direction, and the valve body further has a second through-hole and a third through-hole in the side wall, wherein the second through-hole is communicated with the second sealing area, and the third through-hole is communicated with the third sealing area; the valve core is arranged in the first through-hole and can move axially in the first through-hole, and the valve core is provided with a channel, the channel of the valve core being selectively communicated with the first sealing area, the second sealing area or the third sealing area by moving the valve core axially, the first channel being formed when the channel of the valve core is communicated with the first sealing area, the second channel being formed when the channel of the valve core is communicated with the second sealing area, and the third channel being formed when the channel of the valve core is communicated with the third sealing area.

3. A pressurized water device for free adjustment of the length of a test section downhole according to claim 2, characterized in that a first sealing ring, a second sealing ring and a third sealing ring are arranged in the first through-hole from bottom to top along the axial direction, the valve core is arranged in the first through-hole by penetrating the first sealing ring, the second sealing ring and the third sealing ring, and the first sealing ring, the second sealing ring and the third sealing ring divide the first through-hole into a first sealing area, a second sealing area, a third sealing area and a fourth sealing area.

4. The pressurized water device for freely adjusting the length of a test section in a well according to claim 2, wherein an axially-through shaft hole and a radially-through radial hole are arranged in the valve core, the radial hole is communicated with the shaft hole, the radial hole is communicated with the first sealing area when the drill pipe drives the valve core to drop to the maximum stroke in the through-hole, and the radial hole is communicated with the third sealing area when the drill pipe drives the valve core to lift to the maximum stroke.

5. The pressurized water device for freely adjusting the length of a test section downhole according to claim 1, wherein, the three-channel switching valve is connected with a high-pressure water pump through the drill pipe.

6. The pressurized water device for freely adjusting the length of a test section downhole according to claim 5, wherein, the water pressurizing device further comprises a pressure and flow monitoring device.

7. A pressurized water device for free adjustment of the length of a test section downhole according to claim 6, characterized in that the pressure and flow monitoring device comprises a pressure sensor, a flow sensor, a data acquisition device electrically connected with the pressure sensor and the flow sensor, and a data processing device electrically connected with the data acquisition device, wherein the pressure sensor is arranged at the orifice of the drill pipe, and the flow sensor is arranged at the water outlet end of the high-pressure water pump.

8. A method of using a pressurized water device for free adjustment of the length of a test section in a well according to any one of claims 1-7, characterized in that, the method comprises the following steps: Step 1, after the water pressurizing device is placed in the borehole at a predetermined depth, the drill pipe is lifted, the three-way switching valve is moved downward to the maximum stroke under the gravity of the upper and lower plugs and the telescopic rod, the third passage is connected, water is injected into the third passage and pressurized to a predetermined value, the water is injected into the lower plug in turn through the third passage and the third pipeline, the lower plug is expanded and tightly attached to the borehole wall under the action of water and pressure, at this time, the lower end of the test section is sealed; Step 2, the drill pipe is lowered to the first passage of the three-way switching valve, then the position of the upper plug is adjusted to adjust the length of the telescopic rod to obtain a suitable test section length, water is injected into the first passage and pressurized to a predetermined value, the water is injected into the upper plug through the first passage and the first pipeline, the upper plug is expanded and tightly attached to the borehole wall under the action of water and pressure, at this time, the upper end of the test section is sealed; Step 3, the drill pipe is lifted to the second passage of the three-way switching valve, the water channel leads to the test section, at this time, the water pressure test is completed in the test section according to the requirements of the survey specification; Step 4, after the water pressure test is completed, the drill pipe is lifted upward to the third passage, the water in the lower plug is discharged through the third passage and the third pipeline until the lower plug is contracted and separated from the hole wall; Step 5, the drill pipe is lowered to the first passage of the three-way switching valve, the water in the upper plug is discharged through the first passage and the first pipeline until the upper plug is contracted and separated from the hole wall, at this time, the entire water pressurizing device is unsealed from the borehole and can move freely in the borehole; Step 6, the water pressurizing device is moved to other positions and the length of the test section is adjusted as needed to perform the next test; Wherein, step 4 and step 5 can be interchanged in sequence.

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