A double plug device for water expansion test of wire-line coring drill

Abstract

The application discloses a kind of based on rope coring drill string water pressure test expansion water stop double embolism device, including positioning kit, connecting portion, hollow rod and expansion water stop plug, connecting portion connects positioning kit and hollow rod, expansion water stop plug is movably sleeved on hollow rod with interval, and is connected by connecting sleeve therebetween to form water pressure test section, water injection hole is provided on the side wall of hollow rod corresponding to expansion water stop plug, hollow rod can be axially moved relative to double expansion water stop plug, wherein one expansion water stop plug is provided with water injection hole sealing water sleeve pipe that is closed and staggered.The application is arranged with interval by two expansion water stop plugs, and forms water pressure test section with the hole wall of drilling hole therebetween, guarantees the sealing of upper and lower ends of test section, can make test work and drilling work partially or wholly separate, effectively improve work efficiency;The position of plug placement and test section length can be reasonably determined according to the actual situation in hole, and the correlation between test results and geological conditions is better.

Description

Technical Field

[0001] This invention relates to the field of exploration technology, and in particular to a double-plug device for expanding and stopping water pressure testing based on wireline coring drills. Background Technology

[0002] Commonly used test section isolation methods include single-plug and double-plug isolation. Single-plug isolation is mainly used for test sections that are drilled section by section as the borehole deepens, and water pressure tests are conducted section by section. In some cases, such as when the rock mass is intact and the borehole wall is stable, and it is necessary to continue water pressure testing on a certain section of the borehole based on the actual situation of the borehole, double-plug water pressure testing is usually used.

[0003] Chinese utility model patent (CN21619780U) discloses a sliding rod lifting mechanical expansion plug, which includes a drill rod thread, a hollow sliding rod, an expansion hose, and a sealing plug. The drill rod thread is fixedly connected to the upper end of the hollow sliding rod, and the lower end of the hollow sliding rod is sealed with a sealing plug. The expansion hose is sleeved on the hollow sliding rod. A water injection hole is opened in the wall of the hollow sliding rod. There are two sealing sleeves, both sleeved on the hollow sliding rod and fixed to the upper and lower ends of the expansion hose, respectively. A compression spring is sleeved on the hollow sliding rod and located between the drill rod thread and the upper sealing sleeve. This design eliminates the need for additional pipes connected to a dedicated water pump or compressed air compressor, reducing production costs and simplifying the process, making construction faster and more convenient. In use, as the drill rod drives the drill rod thread and the hollow sliding rod downwards, the downward pressure on the drill rod causes the compression spring to contract and the hollow sliding rod to slide downwards relative to the expansion hose. Because the compression spring has elastic force when compressed, it exerts a downward force on the expansion hose, causing the expansion hose to tend to move downward. This results in the expansion hose sliding down in the borehole, affecting the actual water pressure test measurement. Therefore, the friction between the expansion hose and the borehole during expansion needs to overcome the downward pressure of the compression spring.

[0004] Chinese utility model patent (CN202039837U) discloses a water pressure testing device for wireline coring drilling without drilling. The device includes a borehole testing section, with a hollow drill rod fixed to its top via a borehole clamp. The upper end of the drill rod is coaxially connected to a hollow vertical shaft, which is fitted with a bushing and connected to a vertical shaft chuck of the drilling rig. A drill bit is connected to the lower end of the drill rod, and a reducing joint suspends and seals the drill bit. The interior of this sealing device is connected to a water pump located outside the borehole via the drill rod, vertical shaft, and high-pressure hose. This utility model is mainly applicable to testing the permeability of rock masses in 75mm diameter wireline coring boreholes. This pressure testing device incorporates a limiting device on the sealing assembly to prevent the pressure-resistant hose from slipping. This limiting device includes a limiting through-hole radially extending from the lower connector. Within this hole, a steel ball (5mm in diameter), a spring (8mm in length), and a screw threaded into the through-hole are placed sequentially from the center outwards. A groove corresponding to the position of the steel ball is formed on the outer wall of the guide rod; in this example, this groove is 6cm from the lower end of the guide rod. In practical use, the pressure of the limiting device can be adjusted using the screw, and the steel ball or spring can be replaced by removing or installing the screw. The addition of a limiting through-hole and the fitting screw or spring and steel ball to the sealing assembly increases the processing difficulty and raises the manufacturing cost of the device.

[0005] The existing water pressure testing devices mentioned above are all single-plug water pressure testing devices, which are drilled section by section as the borehole deepens and water pressure testing is performed section by section. They cannot meet the needs of working conditions that require double-plug water pressure testing. Summary of the Invention

[0006] The purpose of this invention is to provide a double-plug device for pressure testing of wireline coring drills with expansion plugs. Two expansion plugs are spaced apart, forming a pressure testing section with the borehole wall between them. This ensures the sealing of both ends of the testing section, allowing the testing work to be partially or completely separated from the drilling work, thus improving efficiency. At the same time, the placement of the plugs and the length of the testing section can be reasonably determined according to the actual situation inside the borehole, and the test results have a good correlation with geological conditions.

[0007] To achieve the above objectives, the technical solution provided by the present invention is: a double-plug device for pressure testing of wireline coring drills, comprising a positioning kit, a connecting part, a hollow rod, and expansion plugs. The connecting part connects the positioning kit and the hollow rod. The expansion plugs are movably sleeved on the hollow rod at intervals and connected to each other through connecting sleeves to form a pressure testing section. A water injection hole is provided on the side wall of the hollow rod corresponding to the expansion plug. The hollow rod can move axially relative to the double expansion plugs. One of the expansion plugs is provided with a sealing sleeve to close the misaligned water injection hole.

[0008] This invention employs the aforementioned technical solution, where the positioning kit, connecting part, and hollow rod are connected sequentially from top to bottom. Water for the test flows through the connecting part into the inner cavity of the hollow rod and out through the injection hole. Before the pressure test, the injection hole is located inside the double expansion plugs. Water flows from the injection hole into the spaced-apart expansion plugs, inflating them and sealing them tightly against the borehole wall. The hollow rod then moves with the positioning kit and connecting part, causing it to move axially relative to the expansion plugs. The injection hole exposes the pressure test section between the two expansion plugs, where a pressure test is performed. The lower expansion plug is equipped with a sealing sleeve to seal the injection hole exposed outside the lower expansion plug, ensuring that test water can only enter the sealed test section through the upper injection hole. The length of the connecting sleeve between the expansion plugs matches the length of the pressure test section to ensure the distance between the double expansion plugs. By sealing the upper and lower ends of the test section with double expansion plugs, this invention allows for flexible water pressure testing at any location in the borehole.

[0009] The aforementioned double-plug expansion seal device for water pressure testing based on wireline coring drills involves a connecting sleeve fitted onto a hollow rod, with expansion seal plugs connected to both ends. The side wall of the connecting sleeve has water passage holes. The double expansion seal plugs, spaced apart, serve a positioning function. When the hollow rod moves, causing the water injection hole to expose the expansion seal plug, the water injection hole is located inside the connecting sleeve. Water flowing from the injection hole flows into the test section through the water passage holes on the side wall of the connecting sleeve, completing the water pressure test.

[0010] The aforementioned double-plug device for expanding water stop based on water pressure testing of wireline coring drills has a connector at the top of the hollow rod, which connects to the connecting part, and a limiting device at the bottom of the hollow rod. The limiting device is used to prevent the expanding water stop plug from running out from the bottom of the hollow rod when it is lowered into the borehole, and to bring the expanding water stop plug out when it is retrieved.

[0011] The aforementioned double-plug device for expanding water stop based on wireline coring drill water pressure testing includes a locking nut and a washer at the bottom of the hollow rod. The locking nut and washer are detachably connected to the hollow rod, facilitating maintenance and replacement of the double-expansion water stop plugs.

[0012] The aforementioned double-plug device for expanding and sealing water during water pressure testing using a wireline coring drill has a sealing plug at the bottom of the hollow rod. The bottom of the hollow rod is sealed by the sealing plug, ensuring that the water used in the test can only flow out from the injection hole.

[0013] The aforementioned double-plug device for water pressure testing of wireline coring drills features an expansion chamber inside the expansion plug. Water flowing from the hollow rod continuously enters the expansion chamber, causing the expansion plug to expand and seal the test section.

[0014] The aforementioned expansion-sealing double-plug device for water pressure testing based on wireline coring drills comprises a pressure-resistant expansion hose, a crimping insert, and a crimping sleeve. Both ends of the pressure-resistant expansion hose are connected to the crimping insert via the crimping sleeve for a crimped seal. The expansion-sealing plug is fitted onto a hollow rod. The crimping insert and crimping sleeve work together to tightly fit both ends of the pressure-resistant expansion hose onto the hollow rod. When water is injected into the pressure-resistant expansion hose, both ends remain tightly connected to the hollow rod. Water from the inner cavity of the hollow rod flows into the pressure-resistant expansion hose through the injection hole, causing it to expand. During expansion, the outer surface of the pressure-resistant expansion hose adheres tightly to the borehole wall, sealing the upper and lower parts of the drilled water pressure test section, thus achieving a seal for the water pressure test section.

[0015] The aforementioned double-plug device for expanding water stop based on wireline coring drilling and water pressure testing has an end cap at the upper end of the expansion water stop plug. The end cap connects to the crimping insert, and a sealing element is provided between the end cap and the crimping insert. The end cap is used to install the sealing element and adjust the sealing effect. The sealing element is located between the end cap and the crimping insert and is used to seal the mating area between the expansion plug and the hollow rod.

[0016] The aforementioned double-plug device for expanding water stop based on water pressure testing of wireline coring drills has connecting seats at both ends of the connecting sleeve. The connecting seats are connected to the crimping core of the expanding water stop plug, and the connection is sealed by a sealing element. The two ends of the connecting sleeve are connected to the expanding water stop plug via connecting seats, and the connection is sealed by a sealing element.

[0017] The aforementioned double-plug device for expanding water stop based on water pressure testing of wireline coring drills has an upper connector and a lower connector at each end of the sealing sleeve. The upper connector is connected to the crimping core of the expanding water stop plug, and a sealing fit is achieved between them via a sealing element. The lower connector is connected to a sealing sleeve, and a sealing fit is achieved between the lower connector and the sealing sleeve via the sealing element. The top end of the sealing sleeve is connected to the expanding water stop plug via the upper connector, and the bottom end is connected to the sealing sleeve via the lower connector, achieving a seal between the sleeve and the hollow rod.

[0018] The aforementioned double-plug device for expanding and sealing water during water pressure testing using a wireline coring drill includes a central tube and an inner tube. The central tube is connected to a positioning kit, and the top end of the inner tube is connected to the central tube, while the bottom end is connected to the hollow rod. The central tube communicates with the inner tube, guiding the pressure water used in the test axially into the inner tube, and then into the interior of the hollow rod.

[0019] The aforementioned expansion-stop double-plug device based on wireline coring drill water pressure testing includes a positioning kit comprising a spear-retrieval mechanism and a spring-loaded clamping mechanism. The spear-retrieval mechanism is connected to the spring-loaded clamping mechanism, which is connected to the central tube. The spear-retrieval mechanism is used to hoist the expansion-stop plug kit. After the core is retrieved, the expansion-stop plug kit is hoisted into the outer tube assembly via a retrieval tool connected to the spear-retrieval mechanism. The spring-loaded clamping mechanism is used to install and position the expansion-stop plug kit. During use, the spring-loaded clamping mechanism is positioned within the outer tube assembly, serving a positioning function.

[0020] The aforementioned expansion sealing double plug device based on wireline coring drill water pressure testing includes a spring-loaded clamp mechanism comprising a spring-loaded clamp frame, spring-loaded clamps, and a spring. The spring-loaded clamps are mounted on the spring-loaded clamp frame, and the spring causes the two wings of the spring-loaded clamps to expand radially. The bottom end of the spring-loaded clamp frame is connected to the central tube, and a water injection channel is provided at the bottom end of the spring-loaded clamp frame, which communicates with the central tube. The spring-loaded clamps, through the spring, expand radially at their two wing ends and abut against the bottom end of the spring-loaded clamp stop of the outer tube assembly, positioning the expansion sealing plug kit in place. The spring-loaded clamp frame has a water injection channel, from which pressurized water for testing flows axially into the central tube.

[0021] The aforementioned double-plug device for expanding water stop based on water pressure test of wireline coring drill bit also includes an outer tube assembly, a positioning kit, a connecting part, a hollow rod and an expanding water stop plug assembled in the outer tube assembly, the expanding water stop plug extending out of the bottom end of the outer tube assembly, and a sealing rubber ring provided between the outer tube assembly and the central tube.

[0022] The present invention relates to a double-plug device for expanding and sealing water during water pressure testing of wireline coring drills. A spring-loaded mechanism is used for mounting and positioning the device. A sealing ring is installed between the outer tube assembly and the central tube to ensure a seal between them. When test water enters from the outer tube assembly and passes through the water injection channel on the spring-loaded bracket, the sealing ring prevents water from entering between the outer and inner tubes. Instead, the water flows through the injection channel into the central tube and then into the hollow rod through the inner tube. Water is injected into the expanding and sealing plugs, and a water pressure test is conducted on the test section when the injection hole is exposed in the test section.

[0023] The aforementioned double-plug device for water pressure testing based on wireline coring drills comprises an outer tube assembly including a spring-loaded stop, a spring-loaded chamber, and an outer tube, connected sequentially from top to bottom. The spring-loaded mechanism is positioned within the spring-loaded chamber. When the two wings of the spring-loaded clamp are extended, they abut against the bottom of the spring-loaded stop. A seat ring is provided on the inner side of the outer tube, and a sealing rubber ring is installed between the seat ring and the central tube. A reamer and a drill bit are located at the bottom of the outer tube. The outer tube is used to connect the drill rod. The drill rod drives the outer tube to rotate, creating a borehole through the drill bit and reamer. After drilling to a predetermined position, the drill rod is lifted, and the spring-loaded clamp is positioned against the bottom of the spring-loaded stop and assembled in the outer tube assembly, allowing for water pressure testing.

[0024] The aforementioned double-plug device for expanding and sealing water during water pressure testing based on wireline coring drills features a centralizing ring on the inner side of the reamer, which ensures the coaxiality of the inner and outer tubes. During the water pressure test, the centralizing ring guarantees the coaxiality of the inner and outer tubes.

[0025] The beneficial effects of this invention are as follows: By using a double-plug kit, the upper and lower ends of the test section of the borehole can be sealed specifically, reducing interference and impact on the test section; effectively ensuring the water pressure test results. This invention uses a single hollow rod for water injection expansion sealing and water injection pressure testing, and only one pressure system is needed to complete the test, reducing testing costs. This invention allows for water pressure testing at any position in the borehole, enabling testing at the desired location after drilling. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a double-plug device for expanding and sealing water during water pressure testing based on a wireline coring drill according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of the expansion sealing plug according to an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of a double-plug device for expanding and sealing water during water pressure testing based on a wireline coring drill according to an embodiment of the present invention;

[0029] Figure 4 This is an exploded view of the internal structure of a double-plug device for expanding and sealing water during a rope coring and water pressure test according to an embodiment of the present invention.

[0030] Figure 5 yes Figure 3 A schematic diagram of the outer tube assembly in the middle;

[0031] Figure 6 yes Figure 3 Enlarged view of the local structure at point A;

[0032] Figure 7 yes Figure 3 Enlarged view of the local structure at point B;

[0033] Figure 8 This is a schematic diagram of a double-plug device for expanding and stopping water pressure testing based on a wireline coring drill bit, placed in the borehole according to an embodiment of the present invention.

[0034] Figure 9 yes Figure 8 The local structure at point C is shown in the diagram.

[0035] Figure 10 This is a schematic diagram of the structure of a double-plug device for expanding and sealing water under pressure test based on a wireline coring drill in the water injection expansion and sealing test section according to an embodiment of the present invention;

[0036] Figure 11 yes Figure 10 Enlarged view of the local structure at point D;

[0037] Figure 12 This is a schematic diagram of the structure of a double-plug device for expanding water stoppage based on a wireline coring drill during a water injection and pressure test according to an embodiment of the present invention.

[0038] Figure 13 yes Figure 12 Enlarged view of the local structure at point E in the middle.

[0039] Explanation of reference numerals in the attached drawings: Positioning kit 1, Spear retrieval mechanism 11, Spring-loaded mechanism 12, Spring-loaded bracket 121, Spring-loaded clamp 122, Embedded spring 123, Water injection channel 124, Connecting part 2, Central tube 21, Inner tube 22, Sealing ring 23, Step 24, Hollow rod 3, Water injection hole 31, Connector 32, Limiting device 33, Locking nut 331, Washer 332, Sealing plug 34, Expansion stop plug 4. Pressure-resistant expansion hose 41, plug end cap 42, crimping insert 43, crimping sleeve 44, seal 45, connecting sleeve 5, water inlet 51, connecting seat 52, water sealing sleeve 6, upper connector 61, lower connector 62, sealing sleeve 63, outer tube assembly 7, spring clip stop 71, spring clip chamber 72, outer tube 73, seat ring 74, reamer 75, drill bit 76, straightening ring 77, drill hole 8, test section 81. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0041] Reference Figure 1 and Figure 2As shown, a double-plug device for pressure testing of wireline coring drills includes a positioning kit 1, a connecting part 2, a hollow rod 3, and expansion plugs 4. The connecting part 2 connects the positioning kit 1 and the hollow rod 3. The positioning kit 1, the connecting part 2, and the hollow rod 3 are connected sequentially from top to bottom. The expansion plugs 4 are movably sleeved on the hollow rod 3 at intervals and connected by connecting sleeves 5 to form a pressure test section. The interval between the upper expansion plug 4 and the lower expansion plug 4 is the pressure test section, and the distance of this section matches the length of the test section 81 in the borehole 8. A water injection hole 31 is provided on the side wall of the hollow rod 3 corresponding to the expansion plug 4. The hollow rod 31 can move axially relative to the double expansion plugs 4, so that the water injection hole 31 can switch between the inside and outside of the double expansion plugs 4. One of the expansion plugs 4 is provided with a sealing sleeve 6 to close the misaligned water injection hole 31. When the water injection hole 31 is located inside the double expansion water stop plug 4, water is injected into the double expansion water stop plug 4 through the water injection hole 31, causing the double expansion water stop plug 4 to expand, so that its outer surface contacts and squeezes the hole wall of the drilled hole 8 to seal it. The double expansion water stop plugs 4, which are spaced apart, simultaneously seal the two ends of the test section 81. When the water injection hole 31 is exposed outside the double expansion water stop plug 4, water is injected into the test section 81 for a water pressure test.

[0042] The hollow rod 3 can move downwards or upwards relative to the double-expansion water-stop plug 4, the purpose of which is to switch the position of the water injection hole 31 inside and outside the double-expansion water-stop plug 4. When the hollow rod 3 moves upwards relative to the double-expansion water-stop plug 4 to switch the water injection hole 31 for a water injection test, the sealing sleeve 6 is set on the upper expansion water-stop plug 4. When the hollow rod 3 moves downwards relative to the double-expansion water-stop plug 4 to switch the water injection hole 31 for a water injection test, the sealing sleeve 6 is set on the lower expansion water-stop plug 4. In this embodiment, the movement of the hollow rod 3 relative to the double-expansion water-stop plug 4 is that the hollow rod 4 slides within the double-expansion water-stop plug 4.

[0043] A connecting sleeve 5 is fitted onto a hollow rod 3, with expansion plugs 4 connected to both ends. The side wall of the connecting sleeve 5 is provided with a water passage hole 51. When the hollow rod 3 slides so that its water injection hole 31 is exposed outside the double expansion plugs 4 and located between the double expansion plugs 4, the water flowing out of the water injection hole 31 flows out through the water passage hole 51 of the connecting sleeve 5 and enters the test section 81 to achieve a water pressure test.

[0044] The hollow rod 3 has a connector 32 at its top end, which connects to the connecting part 2. A limiting device 33 is located at the bottom end of the hollow rod 3. The limiting device 33 includes a locking nut 331 and a washer 332, both positioned at the bottom end of the hollow rod 3. A sealing plug 34 is located at the bottom end of the hollow rod 3. The locking nut 331 is threaded onto the sealing plug 34, and the washer 332 is located between the locking nut 331 and the bottom end of the hollow rod 3.

[0045] The expansion plug 4 includes a pressure-resistant expansion tube 41, a crimping insert 43, and a crimping sleeve 44. Both ends of the pressure-resistant expansion tube 41 are crimped and sealed to the crimping insert 43 via the crimping sleeve 44. The expansion plug 4 is fitted onto the hollow rod 3. After the pressure-resistant expansion tube 41 is pressed tightly against the hollow rod 3, the hollow rod 3 can still slide within the pressure-resistant expansion tube 41. The expansion plug 4 has a water-injection expansion chamber 40 inside.

[0046] The upper end of the expansion plug 4 is provided with a plug end cap 42, which is connected to the crimping core 43. A sealing element 45 is provided between the plug end cap 42 and the crimping core 43. Both ends of the connecting sleeve 5 are provided with connecting seats 52, which are connected to the crimping core 43 of the expansion plug 4 and sealed between them by the sealing element 45.

[0047] The sealing element 45 ensures the watertightness between the pressure-resistant expansion hose 41 and the hollow rod 3 during water expansion. The plug end cap 42 and the crimping insert 43 can be connected by threads.

[0048] The sealing sleeve 6 has an upper connector 61 and a lower connector 62 at each end. The upper connector 61 is connected to the crimping core 43 of the expansion stop plug 4 and is sealed in place by a sealing element 45. The lower connector 62 is connected to a sealing sleeve 63 and is sealed in place by a sealing element 45.

[0049] The sealing element 45 is composed of multiple layers, and its thickness is greater than the outer diameter of the water injection hole 31. This ensures that the water injection hole 31 maintains a good seal with the hollow rod 3 when it passes through the sealing element 45 during axial movement.

[0050] The connecting part 2 includes a central tube 21 and an inner tube 22. The central tube 21 is connected to the positioning kit 1. The top end of the inner tube 22 is connected to the central tube 21, and the bottom end is connected to the hollow rod 3. The hollow rod 3 is connected to the inner tube 22 through a connector 32. The bottom end of the hollow rod 3 is sealed by a sealing plug 34. A locking nut 331 and a washer 332 are provided on the sealing plug 34 to prevent the expansion stop plug 4 from sliding out of the bottom end of the hollow rod 3.

[0051] The positioning kit 1 includes a spear-retrieving mechanism 11 and a spring-loaded mechanism 12. The spear-retrieving mechanism 11 is connected to the spring-loaded mechanism 12, and the spring-loaded mechanism 12 is connected to the central tube 21.

[0052] The spring-loaded mechanism 12 includes a spring-loaded bracket 121, a spring-loaded clamp 122, and a spring 123. The spring-loaded clamp 122 is mounted on the spring-loaded bracket 121, and the spring 123 causes the two wings of the spring-loaded clamp 122 to expand radially. The bottom end of the spring-loaded bracket 121 is connected to the central tube 21, and the bottom end of the spring-loaded bracket 121 is provided with a water injection channel 124, which communicates with the central tube 21. The water injection channel 124 is used to guide the pressurized water for testing into the central tube 21, transport it axially to the inner tube 22, and then flow into the hollow rod 3.

[0053] Further reference Figures 1 to 7 As shown, the present invention also includes an outer tube assembly 7, a positioning kit 1, a connecting part 2, a hollow rod 3 and an expansion stop plug 4 assembled in the outer tube assembly 7, the expansion stop plug 4 extending out of the bottom end of the outer tube assembly 7, and a sealing ring 23 provided between the outer tube assembly 7 and the central tube 21.

[0054] The outer tube assembly 7 includes a spring-loaded stop head 71, a spring-loaded chamber 72, and an outer tube 73, which are connected sequentially from top to bottom. The spring-loaded mechanism 12 is positioned in the spring-loaded chamber 72. When the two wings of the spring-loaded clamp 122 are unfolded, they abut against the bottom end of the spring-loaded stop head 71. A seat ring 74 is provided on the inner side of the outer tube 73, and a sealing ring 23 is provided between the seat ring 74 and the central tube 21. A reamer 75 and a drill bit 76 are provided at the bottom of the outer tube 73. The central tube 21 has a step 24, which abuts against the seat ring 54 when the expansion plug kit 1a is assembled, positioning the expansion plug kit 1a in the outer tube 53. A straightening ring 77 is provided on the inner side of the reamer 75, which makes the inner tube 22 and the outer tube 73 coaxial.

[0055] Figures 3 to 13 As shown, the outer tube assembly 7 is connected to the drill rod. The drill rod is driven to rotate by the drilling machine, which drives the outer tube assembly 7 to drill a hole. When the drilling reaches the predetermined position, the inner tube assembly is first lifted out of the outer tube assembly 7. Then, the outer tube assembly 7 is lifted by the drilling machine to a distance from the bottom of the hole. This distance is the pressure test section.

[0056] During the test, the hollow rod 3 and the double-expansion water-stop plug 4 extend beyond the drill bit 76 and are located in the test section 81. During the test, water is pumped into the drill rod and then into the outer pipe assembly 7. The water flows through the water injection channel 124 into the central pipe 21 and inner pipe 22, then into the inner cavity of the hollow rod 3, and finally flows out from the water injection hole 31 to fill the interior of the double-expansion water-stop plug 4. When sealing the test section 81 with water, the water pressure inside the upper and lower expansion water-stop plugs 4 typically reaches 2 to 3 times that of the pressure test. After the expansion water-stop plug 4 expands with water, its radial expansion causes its pressure-resistant expansion hose 41 to contract axially towards the center, resulting in a certain pulling and deformation at both ends, causing the upper and lower ends of the double-expansion water-stop plug 4 to retract axially a certain distance. The expansion pressure of the lower expansion plug 4 is less than that of the upper expansion plug 4, which ensures that the lower part of the test section 81 is sealed first and then the upper part of the test section 81 is sealed. This also solves the problem that the reliability of the lower plug of the traditional double plug is not easy to check.

[0057] After the water pressure inside the upper and lower expansion plugs 4 reaches a stable value, the water pump pressure is maintained. The drill rod is driven down by the drilling rig, which in turn drives the outer pipe assembly 7 down, along with the positioning kit 1, the connecting part 2, and the hollow rod 3. The hollow rod 3 descends in the borehole 8. As the upper and lower expansion plugs 4 expand with water, their outer surfaces adhere tightly to the borehole wall of the borehole 8, sealing them. The hollow rod 3 slides relative to the double expansion plugs 4 until the water injection hole 31 is exposed outside the double expansion plugs 4. At this time, the water pump continues to pump water, and the water flows out from the water injection hole 31 and into the test section 81, allowing for a pressure test.

[0058] The pressurized water flowing out of the water injection hole 31 enters the connecting sleeve 5 and flows out from the water passage hole 51 of the connecting sleeve 5 into the test section 81, thereby realizing the pressure test of the test section 81. When the water injection hole 31 located below the hollow rod 31 is exposed outside the expansion stop plug 4, the water flowing out of the water injection hole 31 stays in the sealing sleeve 6.

[0059] After the water pressure test is completed, the drilling rig lifts the drill rod upwards, causing the double-plug device for water pressure testing based on wireline coring to move upwards. This causes the hollow rod 3 to move axially upwards. As the hollow rod 3 moves upwards, its injection hole 31 moves into the upper and lower expansion plugs 4. Because the water pressure inside the double expansion plugs 4 is greater than the water pressure inside the hollow rod 3, the water inside the expansion plugs 4 flows from the injection hole 31 into the hollow rod 3 to release pressure. After the pressure is released, the double expansion plugs 4 contract and separate from the borehole wall 8. The double-plug device for water pressure testing based on wireline coring can be lifted out by connecting the retrieval spear mechanism 11 to the retrieval device on the drilling rig.

[0060] In this water pressure test, the position of the injection hole 31 is changed to achieve the water-filling expansion sealing test section and the water pressure test, which is convenient to operate and has low cost. Moreover, in specific implementation, water pressure tests can be performed at different positions of the borehole 8. That is, after the drill rod drives the outer pipe assembly 7 to rotate and the borehole 8 is drilled by the drill bit 76, the water pressure test is performed. The water pressure test is conducted on the drilled borehole 8 according to the water pressure test procedure, starting from the bottom of the hole and sequentially testing at different positions from bottom to top in the borehole 8, which is flexible. For boreholes requiring testing at multiple different locations, the water pressure test can be completed sequentially in one go, effectively improving work efficiency.

[0061] In summary, as described in the specification and figures, the present invention has been manufactured into actual samples and subjected to multiple usage tests. The results of these tests demonstrate that the present invention achieves its intended purpose, and its practical value is undeniable. The embodiments described above are merely illustrative examples and are not intended to limit the present invention in any way. Any person skilled in the art who makes partial modifications or alterations to the technical content disclosed in the present invention, without departing from the scope of the technical features of the present invention, shall still fall within the scope of the technical features of the present invention.

Claims

1. A double-plug device for expanding and sealing water based on water pressure testing of wireline coring drills, characterized in that: The device includes a positioning kit (1), a connecting part (2), a hollow rod (3), and an expansion stop plug (4). The connecting part (2) connects the positioning kit (1) and the hollow rod (3). The expansion stop plug (4) is movably sleeved on the hollow rod (3) at intervals and connected to each other through a connecting sleeve (5) to form a pressure test section. A water injection hole (31) is provided on the side wall of the hollow rod (3) corresponding to the expansion stop plug (4). The hollow rod (3) can move axially relative to the double expansion stop plug (4). One of the expansion stop plugs (4) is provided with a sealing sleeve (6) to close the misaligned water injection hole (31). The connecting sleeve (5) is fitted onto the hollow rod (3), and its two ends are connected to the expansion stop plugs (4). The side wall of the connecting sleeve (5) is provided with a water passage hole (51). The sealing sleeve (6) is provided with an upper connector (61) and a lower connector (62) at both ends. The upper connector (61) is connected to the crimping core (43) of the expansion stop plug (4) and is sealed in place by a sealing element (45). The lower connector (62) is connected to a sealing sleeve (63) and is sealed in place by a sealing element (45). The expansion plug (4) includes a pressure-resistant expansion hose (41), a crimping insert (43) and a crimping sleeve (44). The two ends of the pressure-resistant expansion hose (41) are crimped and sealed to the crimping insert (43) through the crimping sleeve (44). The expansion plug (4) is sleeved on the hollow rod (3).

2. The double-plug device for expansion and water sealing based on water pressure test of wireline coring drill bit according to claim 1, characterized in that: The top end of the hollow rod (3) is provided with a connector (32), which is connected to the connecting part (2), and the bottom end of the hollow rod (3) is provided with a limiting device (33).

3. The double-plug device for expansion and water sealing based on water pressure test of wireline coring drill bit according to claim 2, characterized in that: The limiting device (33) includes a locking nut (331) and a washer (332), which are located at the bottom end of the hollow rod (3).

4. The double-plug device for expansion and water sealing based on water pressure test of wireline coring drill bit according to claim 2, characterized in that: The bottom end of the hollow rod (3) is provided with a sealing plug (34).

5. The double-plug device for expanding and sealing water based on water pressure test of wireline coring drill bit according to claim 1, characterized in that: The expansion plug (4) has a water-injection expansion chamber (40) inside.

6. The double-plug device for expanding and sealing water based on water pressure test of wireline coring drill bit according to claim 1, characterized in that: The upper end of the expansion plug (4) is provided with a plug end cap (42), which is connected to the crimping core (43). A sealing element (45) is provided between the plug end cap (42) and the crimping core (43).

7. The double-plug device for expansion and water sealing based on water pressure test of wireline coring drill bit according to claim 1 or 6, characterized in that: The two ends of the connecting sleeve (5) are provided with connecting seats (52), which are connected to the crimping core (43) of the expansion stop plug (4) and sealed between them by a sealing element (45).

8. The double-plug device for expanding and sealing water based on water pressure test of wireline coring drill bit according to claim 1, characterized in that: The connecting part (2) includes a central tube (21) and an inner tube (22). The central tube (21) is connected to the positioning kit (1), and the top end of the inner tube (22) is connected to the central tube (21), and the bottom end is connected to the hollow rod (3).

9. The double-plug device for expanding and sealing water based on water pressure test of wireline coring drill bit according to claim 8, characterized in that: The positioning kit (1) includes a spear-retrieving mechanism (11) and a spring-loaded mechanism (12). The spear-retrieving mechanism (11) is connected to the spring-loaded mechanism (12), and the spring-loaded mechanism (12) is connected to the central tube (21).

10. The double-plug device for expansion and water sealing based on water pressure test of wireline coring drill bit according to claim 9, characterized in that: The spring clip mechanism (12) includes a spring clip frame (121), a spring clip clamp (122), and a spring clip (123). The spring clip clamp (122) is mounted on the spring clip frame (121), and the spring clip (123) causes the two wings of the spring clip clamp (122) to spread radially. The bottom end of the spring clip frame (121) is connected to the central tube (21), and the bottom end of the spring clip frame (121) is provided with a water injection channel (124), which is connected to the central tube (21).

11. The double-plug device for expanding and sealing water based on water pressure test of wireline coring drill bit according to claim 10, characterized in that: It also includes an outer tube assembly (7), a positioning kit (1), a connecting part (2), a hollow rod (3) and an expansion stop plug (4) assembled in the outer tube assembly (7), the expansion stop plug (4) extends out of the bottom of the outer tube assembly (7), and a sealing ring (23) is provided between the outer tube assembly (7) and the central tube (21).

12. The double-plug device for expanding and sealing water based on water pressure test of wireline coring drill bit according to claim 11, characterized in that: The outer tube assembly (7) includes a spring clip stop (71), a spring clip chamber (72), and an outer tube (73). The spring clip stop (71), the spring clip chamber (72), and the outer tube (73) are connected from top to bottom. The spring clip mechanism (12) is positioned in the spring clip chamber (72). When the two wings of the spring clip clamp (122) are unfolded, they abut against the bottom of the spring clip stop (71). A seat ring (74) is provided on the inner side of the outer tube (73). A sealing ring (23) is provided between the seat ring (74) and the central tube (21). A hole expander (75) and a drill bit (76) are provided at the bottom of the outer tube (73).

13. The double-plug device for expanding and sealing water based on water pressure test of wireline coring drill bit according to claim 12, characterized in that: The inner side of the expander (75) is provided with a straightening ring (77), which makes the inner tube (22) and the outer tube (73) coaxial.

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