Landing sub for horizontal well testing tools

Abstract

The utility model relates to the technical field of downhole tools, and is a releasing sub for horizontal well testing tools, which comprises an upper sub, a valve core, an outer cylinder and a lower sub, the inner side of the lower end of the upper sub is fixedly installed with the valve core, and the valve core comprises a valve rod section and a valve head section arranged in sequence from top to bottom. The utility model has the advantages of reasonable and compact structure, convenient use, and the following effects: the upper sub and the valve core are driven downward by the coiled tubing, the lower conical surface of the conical part is in contact with the end face of the inner hole at the upper end of the lower flow channel blind hole, the fluid in the coiled tubing flows out from the upper flow channel through hole, the upper flow channel blind hole and the upper communication hole in sequence, cannot enter the lower flow channel blind hole, and forms a sealed cavity in the inner part of the outer cylinder; the coiled tubing is pressurized from the ground, the releasing ring is cut off when the pressure reaches a certain value, the releasing ring moves downward, the sealed cavity cannot be sealed at this time, the pressure in the coiled tubing decreases, the releasing of the tool is completed, and the utility model has the characteristics of stability, high efficiency and reliability.

Description

Technical Field

[0001] This utility model relates to the field of downhole tool technology and is a drop-off connector for a horizontal well testing tool. Background Technology

[0002] In the oil and gas extraction sector, accurately acquiring downhole parameters is crucial for assessing reservoir dynamics and developing efficient extraction strategies. Traditional downhole parameter measurement methods, especially in vertical wells, typically rely on surface logging equipment to lower testing instruments into the wellbore via steel cables. However, for certain operations requiring long-term continuous monitoring, such as pressure recovery testing, the entire testing cycle can last for several days or even longer. During this period, expensive surface logging equipment, wellhead blowout preventers, and related auxiliary facilities must remain occupied and cannot be used for other operations. This prolonged equipment occupation not only severely restricts equipment turnover and utilization efficiency but also leads to persistently high overall costs per test, placing a significant burden on the economical and efficient development of oil fields.

[0003] With the increasing development of unconventional oil and gas resources, the application of complex well structures such as horizontal wells and highly deviated wells is becoming more widespread. However, traditional wireline drilling methods face fundamental technical bottlenecks in these well types. Due to the lack of sufficient compressive strength and axial thrust of the wireline, in horizontal or highly deviated well sections with complex well trajectories, its own weight and the friction of the wellbore wall prevent it from advancing effectively, making it difficult to successfully deliver testing instruments to the target measurement layers. This technical limitation makes it impossible to complete the necessary downhole parameter acquisition in these critical well types, resulting in reservoir engineers being unable to obtain accurate formation data. This affects the understanding of oil and gas reservoirs and the optimization of development plans, ultimately restricting the overall recovery rate and economic benefits of oil wells.

[0004] To overcome the challenges of instrument delivery in wells with complex structures, the industry has introduced coiled tubing deployment technology. Coiled tubing, with its excellent flexibility and continuous running capability, can effectively deliver downhole testing instruments to designated locations in horizontal or highly deviated wells, overcoming the limitations of wireline deployment. However, existing coiled tubing toolchains still suffer from incompatibility with instrument deployment operations. Specifically, the widely used coiled tubing release connector is designed as an emergency safety mechanism, primarily for handling extreme situations where downhole tools become stuck. Its working principle typically involves shearing the internal pins by forcefully pulling up or applying pressure with a ball after the tool becomes stuck, thus separating the tool from the coiled tubing and preserving the tubing. This shearing release mechanism, designed for "unblocking," fundamentally conflicts with the precise, controllable, and repeatable deployment and retrieval requirements of conventional instrument deployment operations, failing to meet the requirements for stable and reliable placement and retrieval of downhole testing instruments. Summary of the Invention

[0005] This utility model provides a release connector for horizontal well testing tools, which overcomes the shortcomings of the prior art. It can effectively solve the core problem that the existing coiled tubing release connectors are designed specifically for emergency unblocking, which makes them unable to meet the requirements of accurate and controllable deployment and retrieval of conventional downhole testing instruments.

[0006] The technical solution of this utility model is achieved through the following measures: A drop-off connector for a horizontal well testing tool includes an upper connector, a valve core, an outer cylinder, and a lower connector. The valve core is fixedly installed on the inner side of the lower end of the upper connector. The valve core includes a valve stem section and a valve head section arranged sequentially from top to bottom. The valve stem section has a through-hole for vertical flow passage in the middle. The valve head section has an upper blind hole for upper flow passage that communicates with the through-hole. Several vertically penetrating flow passage grooves are spaced along the circumference of the outer side of the valve head section. Each flow passage groove has an upper connecting hole that communicates with the upper blind hole. The valve head section includes a cylindrical section and a conical section arranged sequentially from top to bottom, with the outer diameter of the cylindrical section being larger than that of the valve stem section. An outer cylinder is provided on the outer side of the lower part of the valve core, and a lower seat is provided on the inner side of the upper end of the outer cylinder. A limiting ring platform is located on the upper side of the column section, and a spring is provided on the outer side of the valve stem section corresponding to the position between the upper connector and the limiting ring platform. A lower connector is provided on the inner side of the lower part of the outer cylinder, and an installation ring groove is provided on the inner side of the lower end of the outer cylinder. A release ring is provided in the installation ring groove. The inner diameter of the release ring is smaller than the inner diameter of the outer cylinder. A sealing ring platform is provided on the outer side of the upper part of the lower connector corresponding to the position of the release ring, and the outer side of the release ring contacts the inner side of the release ring. Several shearing pins are provided at intervals along the circumference on the outer side of the lower part of the outer cylinder, which can fix the outer cylinder, the release ring and the lower connector together. A lower flow channel blind hole is provided on the upper side of the lower connector. Several lower connecting holes that can communicate with the flow channel blind hole are provided at intervals along the circumference on the outer side of the lower connector corresponding to the position below the outer cylinder. The outer diameter of the middle outer side of the conical section is larger than the inner diameter of the lower flow blind hole.

[0007] The following are further optimizations and / or improvements to the above-mentioned utility model technical solution: The above may also include a testing instrument and a placement connector, wherein the testing instrument is fixedly installed on the inner side of the lower end of the lower connector, and the placement connector is fixedly installed on the lower end of the testing instrument.

[0008] The above may also include O-rings, with at least one O-ring spaced vertically between the upper connector and the valve core, at least one O-ring spaced vertically between the valve stem section and the limiting ring platform, at least one O-ring spaced vertically between the release ring and the sealing ring platform, and at least one O-ring spaced vertically between the release ring and the outer cylinder.

[0009] The outer side of the valve head section may have four vertically penetrating flow channels evenly distributed along the circumference.

[0010] The lower connector may have four lower connecting holes evenly distributed around its circumference on its outer side.

[0011] The above may also include a salvage neck, with a salvage neck provided at the upper end of the lower connector.

[0012] This utility model has a reasonable and compact structure and is easy to use. The upper connector and valve core are moved down by the continuous tubing. The lower conical surface of the conical part hits the inner end face of the upper end of the blind hole of the lower flow channel. The fluid in the continuous tubing flows out sequentially from the upper flow channel through hole, the upper flow channel blind hole and the upper connecting hole, and cannot enter the lower flow channel blind hole, so that a sealed cavity is formed inside the outer cylinder. The ground pressurizes the continuous tubing. When the pressure reaches a certain value, the release ring cuts the release pin and moves down. At this time, the sealed cavity cannot be sealed, the pressure in the continuous tubing drops, and the tool is released. It has the characteristics of stability, high efficiency and reliability. Attached Figure Description

[0013] Appendix Figure 1 This is a schematic diagram of the front half-section structure of Embodiment 1 of this utility model.

[0014] Appendix Figure 2 These are schematic diagrams of the main view and half-section structure of embodiments 1 to 6 of this utility model.

[0015] Appendix Figure 3 For the appendix Figure 1 A three-dimensional structural diagram of the valve core.

[0016] The codes in the attached diagram are as follows: 1 is the upper connector, 2 is the valve stem section, 3 is the cylindrical section, 4 is the conical section, 5 is the flow channel through hole, 6 is the upper flow channel blind hole, 7 is the flow channel groove, 8 is the upper connecting hole, 9 is the outer cylinder, 10 is the limiting ring platform, 11 is the spring, 12 is the lower connector, 13 is the release ring, 14 is the sealing ring platform, 15 is the shear pin, 16 is the lower flow channel blind hole, 17 is the lower connecting hole, 18 is the testing instrument, 19 is the landing connector, 20 is the O-ring seal, and 21 is the retrieval neck. Detailed Implementation

[0017] This utility model is not limited to the following embodiments, and the specific implementation method can be determined according to the technical solution of this utility model and the actual situation.

[0018] In this utility model, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as front, back, top, bottom, left, right, etc. The positional relationships are determined based on the layout direction of the attached diagram in the instruction manual.

[0019] The present invention will be further described below with reference to the embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1 , 2As shown in Figure 3, the drop-off connector for the horizontal well testing tool includes an upper connector 1, a valve core, an outer cylinder 9, and a lower connector 12. The valve core is fixedly installed on the inner side of the lower end of the upper connector 1. The valve core includes a valve stem section 2 and a valve head section arranged sequentially from top to bottom. A through-hole 5 is provided in the middle of the valve stem. An upper blind hole 6, whose upper end communicates with the through-hole 5, is provided in the middle of the valve head section. Several through-hole grooves 7 are arranged circumferentially on the outer side of the valve head section. Each groove 7 has an upper connecting hole 8 that communicates with the upper blind hole 6. The valve head section includes a cylindrical section 3 and a conical section 4 arranged sequentially from top to bottom. The outer diameter of the cylindrical section 3 is larger than that of the valve stem section 2. An outer cylinder 9 is provided on the outer side of the lower part of the valve core. A limiting ring platform 10, whose lower side sits on the upper side of the cylindrical section 3, is provided on the inner side of the upper end of the outer cylinder 9, corresponding to the upper connector 1 and the limiting ring platform 12. A spring 11 is provided on the outer side of the valve stem section 2 between the ring platform 10; a lower connector 12 is provided on the inner side of the lower part of the outer cylinder 9, and an installation ring groove is provided on the inner side of the lower end of the outer cylinder 9. A release ring 13 is provided in the installation ring groove. The inner diameter of the release ring 13 is smaller than the inner diameter of the outer cylinder 9. A sealing ring platform 14 is provided on the outer side of the upper part of the lower connector 12 corresponding to the position of the release ring 13, and the outer side of the release ring 13 contacts the inner side of the release ring 13. Several shear pins 15 are provided at intervals along the circumference on the outer side of the lower part of the outer cylinder 9, which can fix the outer cylinder 9, the release ring 13 and the lower connector 12 together; a lower flow channel blind hole 16 is provided on the upper side of the lower connector 12, and several lower connecting holes 17 are provided at intervals along the circumference on the outer side of the lower connector 12 corresponding to the position below the outer cylinder 9, which can communicate with the flow channel blind hole. The outer diameter of the middle outer side of the conical section 4 is larger than the inner diameter of the lower flow blind hole. During use, when the tubing is lowered to the predetermined position, the tool string below the present invention blocks the tubing from narrowing, and the lower connector 12 cannot move. The coiled tubing drives the upper connector 1 and the valve core to move down. The lower conical surface of the valve core's conical part hits the upper inner end face of the lower flow channel blind hole 16 of the lower connector 12. The fluid in the coiled tubing flows out sequentially from the upper flow channel through hole 5, the upper flow channel blind hole 6 and the upper connecting hole 8, and cannot enter the lower flow channel blind hole 16, so that a sealed cavity is formed inside the outer cylinder 9, which increases the fluid pressure in the coiled tubing. When the coiled tubing is pressurized from the ground, when the pressure reaches a certain value, the release ring 13 cuts the release pin, and the release ring 13 moves down. At this time, the sealed cavity cannot be sealed, the pressure in the coiled tubing drops, and the tool is released.

[0020] The drop-out connector for the above-mentioned horizontal well testing tools can be further optimized and / or improved according to actual needs: Example 2: As shown in the attached document Figure 1 , 2As shown in Figure 3, the system also includes a testing instrument 18 and a placement connector 19. The testing instrument 18 is fixedly installed on the inner side of the lower end of the lower connector 12, and the placement connector 19 is fixedly installed on the lower end of the testing instrument 18. During use, the testing instrument 18 and the placement connector 19 are integrated and set below the drop tool described in Embodiment 1, so that this embodiment constitutes a fully functional downhole testing system. The placement connector 19, as a precise anchor point pre-set in the completion string, ensures that the testing instrument 18 can be accurately delivered and stably placed at the target measurement layer, avoiding displacement of the testing instrument 18 downhole, thereby ensuring the accuracy and reliability of the collected data.

[0021] Example 3: As shown in the attached document Figure 1 , 2 As shown in Figure 3, it also includes O-ring seals 20. At least one O-ring seal 20 is provided vertically between the upper connector 1 and the valve core, at least one O-ring seal 20 is provided vertically between the valve stem section 2 and the limiting ring platform 10, at least one O-ring seal 20 is provided vertically between the release ring 13 and the sealing ring platform 14, and at least one O-ring seal 20 is provided vertically between the release ring 13 and the outer cylinder 9. During use, this arrangement facilitates the sealing between the components, thus aiding in the release of the device.

[0022] Example 4: As shown in the appendix Figure 1 , 2 As shown in Figure 3, four vertically connected flow channel grooves 7 are evenly distributed along the circumference on the outer side of the valve head section. This design facilitates fluid flow during use.

[0023] Example 5: As shown in the attached document Figure 1 , 2 As shown in Figure 3, four lower connecting holes 17 are evenly distributed around the outer side of the lower connector 12 along the circumference. This arrangement facilitates fluid flow during use.

[0024] Example 6: As attached Figure 1 , 2 As shown in Figure 3, it also includes a retrieval neck 21, which is provided at the upper end of the lower connector 12. During use, this design facilitates the retrieval of the lower connector 12, the testing instrument 18, and the landing connector 19 after they have been dropped.

[0025] The above technical features constitute the preferred embodiment of this utility model, which has strong adaptability and the best implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

[0026] The specific implementation process of the preferred embodiment of this utility model can be as follows: (1) Select a well gauge of appropriate diameter according to the downhole working conditions and the tubing diameter reduction size, connect the coiled tubing to perform well cleaning, and after well cleaning is completed, connect the horizontal well testing tool to the coiled tubing using a drop-out connector. (2) During the process of the tool entering the well, always pay attention to the weight indicator. If there is an obstruction, lift the tool string, pressurize the tubing, and flush the inner wall of the tubing string to remove impurities or scale from the inner wall of the tubing string and ensure the tool is lowered. (3) When the tubing is lowered to the predetermined position, the lower part of the settling joint 19 presses against the tubing to reduce the diameter. The settling joint 19, the testing instrument 18 and the lower joint 12 of the drop tool cannot move. The continuous tubing drives the upper joint 1 and the valve core to move down. The lower conical surface of the conical part of the valve core presses against the upper inner end face of the blind hole 16 of the lower flow channel of the lower joint 12. (4) The fluid in the coiled tubing flows out sequentially from the upper flow channel through hole 5, the upper flow channel blind hole 6 and the upper connecting hole 8, and cannot enter the lower flow channel blind hole 16, so that a closed cavity is formed inside the outer cylinder 9, and the fluid pressure in the coiled tubing increases. (5) When the pressure is pressurized from the ground into the coiled tubing, when the pressure reaches a certain value, the release ring 13 cuts the release pin and the release ring 13 moves down. At this time, the sealed cavity cannot be sealed, the pressure in the coiled tubing drops, and the tool is released. During the tool release process, the pressure in the coiled tubing rises and falls, which is clearly displayed on the ground to ensure that the release operation is completed. (6) After the hand is dropped, the hand drop ring 13, the lower connector 12, the testing instrument 18 and the landing connector 19 are left in the well. The hand drop ring 13 is fitted on the lower connector 12. Since the length of the upper retrieval neck 21 of the lower connector 12 is much greater than the length of the hand drop ring 13, it does not affect the retrieval of the lower connector 12. The upper retrieval neck 21 of the lower connector 12 is a standard retrieval neck 21, which can be retrieved using GS retrieval tools.

Claims

1. A drop-off connector for a horizontal well testing tool, characterized in that... The system includes an upper connector, a valve core, an outer cylinder, and a lower connector. The valve core is fixedly installed on the inner side of the lower end of the upper connector. The valve core includes a valve stem section and a valve head section arranged sequentially from top to bottom. The valve stem section has a through-hole in the middle, and the valve head section has an upper blind hole in the middle, with its upper end communicating with the through-hole. Several through-holes are arranged circumferentially on the outer side of the valve head section, each groove containing an upper connecting hole that communicates with the upper blind hole. The valve head section includes a cylindrical section and a conical section arranged sequentially from top to bottom, with the outer diameter of the cylindrical section being larger than that of the valve stem section. An outer cylinder is located on the outer side of the lower part of the valve core. A limiting ring platform, whose lower side sits on the upper side of the cylindrical section, is located on the inner side of the upper end of the outer cylinder, corresponding to the upper connector and the limiting ring platform. A spring is provided on the outer side of the valve stem section between the ring platforms; a lower connector is provided on the inner side of the lower part of the outer cylinder, and an installation ring groove is provided on the inner side of the lower end of the outer cylinder. A release ring is provided in the installation ring groove. The inner diameter of the release ring is smaller than the inner diameter of the outer cylinder. A sealing ring platform is provided on the outer side of the upper part of the lower connector corresponding to the release ring position, and the outer side of the lower connector is provided with a sealing ring platform that contacts the inner side of the release ring. Several shear pins are provided at intervals along the circumference on the outer side of the lower part of the outer cylinder, which can fix the outer cylinder, the release ring and the lower connector together. A lower flow channel blind hole is provided on the upper side of the lower connector. Several lower connecting holes that can communicate with the flow channel blind hole are provided at intervals along the circumference on the outer side of the lower connector corresponding to the position below the outer cylinder. The outer diameter of the middle outer side of the conical section is larger than the inner diameter of the lower flow blind hole.

2. The drop-out connector for horizontal well testing tools according to claim 1, characterized in that... It also includes testing instruments and a mounting connector. The testing instruments are fixedly installed on the inner side of the lower end of the lower connector, and the mounting connector is fixedly installed on the lower end of the testing instruments.

3. The drop-out connector for horizontal well testing tools according to claim 1 or 2, characterized in that... It also includes O-rings, with at least one O-ring spaced between the upper connector and the valve core, at least one O-ring spaced between the valve stem section and the limiting ring platform, at least one O-ring spaced between the release ring and the sealing ring platform, and at least one O-ring spaced between the release ring and the outer cylinder.

4. The drop-out connector for horizontal well testing tools according to claim 1 or 2, characterized in that... Four vertically connected flow channels are evenly distributed along the circumference on the outer side of the valve head section.

5. The drop-out connector for horizontal well testing tools according to claim 3, characterized in that... Four vertically connected flow channels are evenly distributed along the circumference on the outer side of the valve head section.

6. The drop-out connector for horizontal well testing tools according to claim 1, 2, or 5, characterized in that... Four lower connecting holes are evenly distributed along the circumference on the outer side of the lower connector.

7. The drop-out connector for horizontal well testing tools according to claim 3, characterized in that... Four lower connecting holes are evenly distributed along the circumference on the outer side of the lower connector.

8. The drop-out connector for horizontal well testing tools according to claim 4, characterized in that... Four lower connecting holes are evenly distributed along the circumference on the outer side of the lower connector.

9. The drop-out connector for horizontal well testing tools according to claim 1, 2, 5, 7, or 8, characterized in that... It also includes a retrieval neck, with a retrieval neck provided at the upper end of the lower connector.

10. The drop-out connector for horizontal well testing tools according to claim 6, characterized in that... It also includes a retrieval neck, with a retrieval neck provided at the upper end of the lower connector.

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