Underground gas flow testing device

Abstract

The invention provides an underground gas flow testing device, which relates to the technical field of oilfield development and production, and comprises a testing main body capable of extending into an oil pipe, a circuit board accommodating structure connected to the testing main body and used for accommodating a circuit board, and a testing cable electrically connected with the circuit board, the testing main body comprises a first main body structure and a second main body structure which are the same in structure and are sequentially connected, a plurality of flow channel structures with different areas are formed between the outer walls of the first main body structure and the second main body structure and the oil pipe, and each flow channel structure is provided with a pressure tapping hole; a first differential pressure sensor is arranged between the first pressure tapping hole and the last pressure tapping hole of the first main body structure, a second differential pressure sensor is arranged between the first pressure tapping hole and the last pressure tapping hole of the second main body structure, and the first differential pressure sensor and the second differential pressure sensor are both electrically connected with the circuit board. According to the invention, the gas injection flow can be accurately tested.

Description

Technical Field

[0001] This invention relates to the field of oilfield development and production technology, and in particular to a downhole gas flow testing device. Background Technology

[0002] Gas drive technology is currently widely used in the development of low-permeability oilfields. Traditional flow measurement tools mostly contain moving parts, which are easily damaged under high pressure, high temperature and corrosive environments, shortening the tool's service life and increasing maintenance costs.

[0003] CN116608912A proposes a fine gas flow test string for stratified gas injection, which uses a Venturi flow meter for flow testing downhole. However, it requires a flow collection test, resulting in low testing efficiency and high complexity of testing tools, making it inconvenient for process implementation.

[0004] Therefore, there is an urgent need for a downhole gas flow testing device to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a downhole gas flow rate testing device to solve the technical problems of low testing efficiency, complex tools, and inconvenience for process implementation in existing gas flow rate testing devices. The various technical effects of the preferred technical solutions provided by this invention are detailed below.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a downhole gas flow testing device, comprising a test body capable of extending into the tubing, a circuit board housing structure connected to the test body for housing a circuit board, and a test cable electrically connected to the circuit board, wherein:

[0008] The test body includes a first main structure and a second main structure that are identical in structure and connected in sequence. The outer walls of the first main structure and the second main structure form multiple flow channel structures with different areas between them and the oil pipe. Each flow channel structure is provided with a pressure tapping hole. A first differential pressure sensor is arranged between the first and last pressure tapping holes of the first main structure, and a second differential pressure sensor is arranged between the first and last pressure tapping holes of the second main structure. Both the first differential pressure sensor and the second differential pressure sensor are electrically connected to the circuit board.

[0009] Preferably, a first flow channel, a second flow channel, and a third flow channel are formed sequentially from top to bottom between the outer wall of the first main structure and the oil pipe. The flow channel area of ​​the first flow channel gradually decreases from top to bottom, the flow channel area of ​​the second flow channel is the same as the flow channel area at the bottom of the first flow channel, and the flow channel area of ​​the third flow channel gradually increases.

[0010] Preferably, a fourth flow channel, a fifth flow channel, and a sixth flow channel are formed sequentially from top to bottom between the outer wall of the second main structure and the oil pipe. The flow channel area of ​​the fourth flow channel gradually decreases from top to bottom, the flow channel area of ​​the fifth flow channel is the same as the flow channel area at the bottom of the sixth flow channel, and the flow channel area of ​​the sixth flow channel gradually increases.

[0011] Preferably, both the first main structure and the second main structure include an upstream portion, a midstream portion, and a downstream portion arranged sequentially from top to bottom, wherein:

[0012] Both the upstream and downstream portions adopt a conical structure, and the upstream and downstream portions are symmetrically arranged along the middle of the midstream portion. The upstream portion is narrower at the top and wider at the bottom, while the downstream portion is wider at the top and narrower at the bottom.

[0013] The midstream section adopts a columnar structure.

[0014] Preferably, the length of the upstream portion is the same as the length of the downstream portion, and the length of the midstream portion is less than the lengths of the upstream portion and the downstream portion.

[0015] Preferably, the diameter of the columnar structure is 40 mm.

[0016] Preferably, the pressure taps include a first pressure tap, a second pressure tap, a third pressure tap, a fourth pressure tap, and a fifth pressure tap arranged sequentially from top to bottom, wherein:

[0017] The upstream portion and the midstream portion of the first main structure are respectively provided with the first pressure tapping hole and the second pressure tapping hole;

[0018] The third pressure tap is provided at the midpoint between the downstream portion of the first main structure and the upstream portion of the second main structure;

[0019] The fourth pressure tap and the fifth pressure tap are respectively provided in the midstream portion and the downstream portion of the second main structure;

[0020] The first differential pressure sensor is located between the first pressure tap and the third pressure tap;

[0021] The second differential pressure sensor is located between the third pressure tap and the fifth pressure tap.

[0022] Preferably, the downhole gas flow testing device further includes a first pressure sensor and a second pressure sensor, wherein:

[0023] The first pressure sensor is disposed in the middle section of the first main structure;

[0024] The second pressure sensor is disposed in the middle section of the second main structure;

[0025] Both the first pressure sensor and the second pressure sensor are electrically connected to the circuit board.

[0026] Preferably, the downhole gas flow testing device further includes a temperature sensor, which is disposed on the testing body and electrically connected to the circuit board.

[0027] Preferably, the downhole gas flow testing device further includes a centralizer, wherein:

[0028] The stabilizer is connected to the outer wall of the test body and is located between the first main body structure and the second main body structure.

[0029] The downhole gas flow testing device provided by this invention includes a test body that can extend into the tubing, a circuit board housing structure connected to the test body for housing a circuit board, and a test cable electrically connected to the circuit board. The overall structure has no moving parts, significantly improving the durability of the equipment and demonstrating a marked improvement in tool reliability compared to turbine flow meters and similar devices. By setting the test body to include a first main structure and a second main structure with identical structures connected sequentially, multiple flow channel structures of different areas are formed between the outer walls of the first and second main structures and the tubing. Each flow channel structure is equipped with pressure taps, and a first differential pressure sensor is arranged between the first and last pressure taps of the first main structure, and a second differential pressure sensor is arranged between the first and last pressure taps of the second main structure. During use, there is no need for flow collection operations such as tubing plugging, resulting in a simple process, high testing efficiency, and strong reliability. By setting up a dual differential pressure test, the gas injection flow rate can be accurately measured. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1This is a schematic diagram of an embodiment of the downhole gas flow testing device of the present invention;

[0032] Figure 2 yes Figure 1 A schematic diagram of the structure placed inside the oil pipe;

[0033] Figure 3 This is a schematic diagram of the structure of the downhole gas flow testing device of the present invention during testing and use.

[0034] In the diagram: 1. Test body; 11. First main structure; 111. Upstream section; 112. Midstream section; 113. Downstream section; 1101. First flow channel; 1102. Second flow channel; 1103. Third flow channel; 12. Second main structure; 1201. Fourth flow channel; 1202. Fifth flow channel; 1203. Sixth flow channel;

[0035] 2. Circuit board; 20. Circuit board housing structure; 3. Test cable; 4. Headgear;

[0036] 51. First differential pressure sensor; 52. Second differential pressure sensor;

[0037] 61. First pressure tap; 62. Second pressure tap; 63. Third pressure tap; 64. Fourth pressure tap; 65. Fifth pressure tap;

[0038] 71. First pressure sensor; 72. Second pressure sensor;

[0039] 8. Temperature sensor; 9. Centralizer;

[0040] 100. Tubing; 200. Sand control tubing string; 300. First gas injection working cylinder; 400. Second gas injection working cylinder; 500. Third gas injection working cylinder; 600. Sealing structure; 700. Positioning seal; 800. Plug; 900. Artificial bottom hole; 1000. Downhole gas flow testing device. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0042] In the description of this invention, it should be understood that the terms "center," "side," "length," "width," "height," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and "side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] Figure 1 This is a structural schematic diagram of this embodiment. Figure 2 yes Figure 1 A schematic diagram of the structure placed inside the oil pipe, as shown below. Figure 1 and Figure 2 As shown, this embodiment provides a downhole gas flow testing device, including a test body 1 that can extend into the tubing 100, a circuit board housing structure 20 connected to the test body 1 for housing a circuit board 2, and a test cable 3 electrically connected to the circuit board 2. In this embodiment, the circuit board housing structure 20 is fixedly connected to the test body 1, and a nozzle 4 is provided on the top of the circuit board housing structure 20. The test cable 3 is connected to the circuit board 2 inside the circuit board housing structure 20 through the nozzle.

[0045] In this embodiment, the test body 1 is the core structure for flow testing, and it will rub against the oil pipe 100 during use. In order to ensure its maximum durability while maintaining measurement accuracy, it is preferably made of high-strength, corrosion-resistant hard alloy material.

[0046] Specifically, the test body 1 includes a first main structure 11 and a second main structure 12 that are identical in structure and connected in sequence. Multiple flow channel structures of different areas are formed between the outer walls of the first main structure 11 and the second main structure 12 and the tubing 100. Each flow channel structure is equipped with pressure tapping holes. This downhole gas flow testing device eliminates the need for a flow collection device, reducing the complexity of installation and operation.

[0047] A first differential pressure sensor 51 is arranged between the first and last pressure taps of the first main structure 11, and a second differential pressure sensor 52 is arranged between the first and last pressure taps of the second main structure 12. The first differential pressure sensor 51 and the second differential pressure sensor 52 are used to test the pressure through the pressure taps, and to measure the flow rate by combining the correlation of the pressure fluctuation signals when the fluid flows through the first main structure 11 and the second main structure 12.

[0048] Both the first differential pressure sensor 51 and the second differential pressure sensor 52 are electrically connected to the circuit board 2. Specifically, in this embodiment, the circuit board 2 is equipped with a data processing unit, which can receive and process data from the first differential pressure sensor 51 and the second differential pressure sensor 52, and send the data to the ground measurement and adjustment instrument.

[0049] As an optional implementation, a first flow channel 1101, a second flow channel 1102, and a third flow channel 1103 are formed sequentially from top to bottom between the outer wall of the first main structure 11 and the oil pipe 100. The flow channel area of ​​the first flow channel 1101 gradually decreases from top to bottom, the flow channel area of ​​the second flow channel 1102 is the same as the flow channel area at the bottom of the first flow channel 1101, and the flow channel area of ​​the third flow channel 1103 gradually increases.

[0050] The outer wall of the second main structure 12 and the oil pipe 100 form a fourth flow channel 1201, a fifth flow channel 1202 and a sixth flow channel 1203 from top to bottom. The flow area of ​​the fourth flow channel 1201 gradually decreases from top to bottom, the flow area of ​​the fifth flow channel 1202 is the same as the flow area at the bottom of the sixth flow channel 1203, and the flow area of ​​the sixth flow channel 1203 gradually increases.

[0051] As an optional implementation, both the first main structure 11 and the second main structure 12 include an upstream portion 111, a midstream portion 112 and a downstream portion 113 arranged sequentially from top to bottom.

[0052] The upstream portion 111 and the downstream portion 113 both adopt a conical structure, and the upstream portion 111 and the downstream portion 113 are symmetrically arranged along the middle of the midstream portion 112. The upstream portion 111 is narrower at the top and wider at the bottom, the downstream portion 113 is wider at the top and narrower at the bottom, and the midstream portion 112 adopts a columnar structure, so that the test body 1 forms a series of symmetrically arranged double conical structures.

[0053] By setting the upstream section 111 to be narrower at the top and wider at the bottom, the flow area of ​​the first flow channel 1101 and the fourth flow channel 1201 gradually decreases. By setting the midstream section 112 to adopt a columnar structure and the downstream section 113 to be wider at the top and narrower at the bottom, the flow area of ​​the third flow channel 1103 and the sixth flow channel 1203 gradually recovers.

[0054] Optionally, in this embodiment, the length of the upstream portion 111 is the same as the length of the downstream portion 113, both being 30mm. The length of the midstream portion 112 is shorter than the lengths of the upstream and downstream portions 113, being 20mm. Furthermore, in this embodiment, the diameter of the columnar structure of the midstream portion 112 is set to 40mm to ensure that the differential pressure formed when the fluid flows through can be accurately captured by the differential pressure sensing unit.

[0055] As an optional implementation, the pressure taps in this embodiment include a first pressure tap 61, a second pressure tap 62, a third pressure tap 63, a fourth pressure tap 64, and a fifth pressure tap 65 arranged sequentially from top to bottom.

[0056] In order to measure differential pressure and calculate flow rate, this embodiment is equipped with pressure taps in the upstream portion 111, midstream portion 112, and downstream portion 113 of the first main structure 11 and the second main structure 12. One pressure tap is provided in the downstream portion 113 of the first main structure 11 and one in the upstream portion 111 of the second main structure 12, resulting in a total of five pressure taps.

[0057] Specifically, the upstream portion 111 and the midstream portion 112 of the first main structure 11 are respectively provided with a first pressure tapping hole 61 and a second pressure tapping hole 62; a third pressure tapping hole 63 is provided at the midpoint between the downstream portion 113 of the first main structure 11 and the upstream portion 111 of the second main structure 12; and a fourth pressure tapping hole 64 and a fifth pressure tapping hole 65 are respectively provided in the midstream portion 112 and the downstream portion 113 of the second main structure 12.

[0058] The first differential pressure sensor 51 is located between the first pressure tap 61 and the third pressure tap 63; the second differential pressure sensor 52 is located between the third pressure tap 63 and the fifth pressure tap 65. By testing the differential pressure value generated by the downhole gas fluid at the test body 1, the flow rate of the downhole gas can be calculated and thus the flow rate can be calculated. The dual differential pressure test is more accurate than the single differential pressure test.

[0059] As an optional implementation, the downhole gas flow testing device further includes a first pressure sensor 71 and a second pressure sensor 72, used to test the pressure of the downhole injected medium via the first pressure sensor 71 and the second pressure sensor 72. Both the first pressure sensor 71 and the second pressure sensor 72 are electrically connected to the circuit board 2. The first pressure sensor 71 is located in the middle section 112 of the first main structure 11; the second pressure sensor 72 is located in the middle section 112 of the second main structure 12. When gas flows through, the injection flow rate can be accurately measured by the correlation of the pressure fluctuation signals from the first pressure sensor 71 and the second pressure sensor 72.

[0060] Furthermore, the downhole gas flow testing device also includes a temperature sensor 8, which is mounted on the testing body 1 and electrically connected to the circuit board. The temperature sensor 8 measures the temperature of the injected medium downhole. A pressure sensor can be used to test the downhole gas conditions and thus perform precise calculations of gas density, etc.

[0061] As an optional implementation, the downhole gas flow testing device also includes a centralizer 9, which is connected to the outer wall of the test body 1 and located between the first main structure 11 and the second main structure 12. By setting the centralizer 9, the test body 1 is ensured to be centered in the tubing 100.

[0062] The working principle of this embodiment is as follows:

[0063] Normal inflation process: such as Figure 3 As shown, during normal gas injection, the injected gas from the wellhead reaches the sand control section through tubing 100. A first gas injection working cylinder 300, a second gas injection working cylinder 400, and a third gas injection working cylinder 500 are installed in each gas injection layer, with a sealing structure 600 between the layers. In use, the gas injection volume for each layer is adjusted by regulating the size of the nozzle on the gas injection working cylinder.

[0064] Gas injection flow rate test process: When a single-layer injection volume test is required, the test body 1 is brought down into the well via test cable 3.

[0065] First, a lower-level flow rate test is conducted. The test cable 3, carrying the test body 1, reaches above the lowest-level gas injection working cylinder, namely the third gas injection working cylinder 500. Due to the centralizer 9, this downhole gas flow rate testing device is centered within the tubing 100. At this point, the injected gas flows through the flow channel structure between the test body 1 and the tubing 100. Because the test body 1 comprises a double-conical structure consisting of a first main structure 11 and a second main structure 12, a pressure difference is generated before and after the cone of the test body 1. The pressure difference generated between the first and second main structures 11 and 12 is measured by the first differential pressure sensor 51 and the second differential pressure sensor 52. The temperature of the downhole injected medium is measured by the temperature sensor 8. Simultaneously, the pressure of the injected medium is measured by the first pressure sensor 71 and the second pressure sensor 72. The flow rate of the injected medium can be calculated under conditions of temperature, pressure, and pressure difference. Furthermore, the injection rate is calculated by the correlation of the pressure fluctuation signals from the first pressure sensor 71 and the second pressure sensor 72 and the time difference of the pressure waves, thereby calculating the flow rate.

[0066] Then, the middle layer flow rate test is performed. After the lower layer flow rate is tested, the gas flow rate test device is raised to the upper part of the second gas injection working cylinder 400. The gas injection volume is calculated in the same way. At this time, the sum of the middle layer and lower layer gas injection flow rates is obtained. Subtracting the flow rate obtained from the lower layer flow rate test, the single-layer injection volume of the middle layer is obtained.

[0067] Finally, the upper layer flow rate is calculated. After testing the intermediate layer flow rate, the gas flow rate testing device is raised to the top of the first injection working cylinder 300, and the upper layer gas injection volume is tested using the same method. After the overall test is completed, the testing tool is raised to the wellhead to complete the downhole stratified injection volume test.

[0068] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A downhole gas flow testing device, characterized in that: The device comprises a test body capable of extending into the interior of an oil pipe, a circuit board accommodating structure connected to the test body for accommodating a circuit board, and a test cable electrically connected to the circuit board, wherein: The test body includes a first main body structure and a second main body structure having the same structure and connected in sequence, a plurality of flow channel structures with different areas are formed between the outer walls of the first main body structure and the second main body structure and the oil pipe, each of the flow channel structures is respectively arranged with a pressure taking hole, a first differential pressure sensor is arranged between the first and last pressure taking holes of the first main body structure, and a second differential pressure sensor is arranged between the first and last pressure taking holes of the second main body structure, and the first differential pressure sensor and the second differential pressure sensor are both electrically connected to the circuit board.

2. The downhole gas flow testing device according to claim 1, characterized in that: A first flow channel, a second flow channel and a third flow channel are formed in sequence from top to bottom between the outer wall of the first main structure and the oil pipe, and the flow channel area of ​​the first flow channel gradually decreases from top to bottom, the flow channel area of ​​the second flow channel is the same as the flow channel area at the bottom of the first flow channel, and the flow channel area of ​​the third flow channel gradually increases.

3. The downhole gas flow testing device according to claim 1, characterized in that: A fourth flow channel, a fifth flow channel and a sixth flow channel are formed in sequence from top to bottom between the outer wall of the second main structure and the oil pipe, and the flow channel area of ​​the fourth flow channel gradually decreases from top to bottom, the flow channel area of ​​the fifth flow channel is the same as the flow channel area at the bottom of the sixth flow channel, and the flow channel area of ​​the sixth flow channel gradually increases.

4. The downhole gas flow testing device according to any one of claims 1 to 3, characterized in that: The first main structure and the second main structure each include an upstream portion, a midstream portion and a downstream portion arranged in sequence from top to bottom, wherein: The upstream part and the downstream part both adopt a conical structure, and the upstream part and the downstream part are symmetrically arranged along the middle of the midstream part, the upstream part is narrow at the top and wide at the bottom, and the downstream part is wide at the top and narrow at the bottom; The midstream part adopts a columnar structure.

5. The downhole gas flow testing device according to claim 4, characterized in that: The length of the upstream portion is the same as that of the downstream portion, and the length of the midstream portion is shorter than the lengths of the upstream portion and the downstream portion.

6. The downhole gas flow testing device according to claim 4, characterized in that: The diameter of the columnar structure is 40 mm.

7. The downhole gas flow testing device according to claim 4, characterized in that: The pressure taking holes include a first pressure taking hole, a second pressure taking hole, a third pressure taking hole, a fourth pressure taking hole and a fifth pressure taking hole arranged in sequence from top to bottom, wherein: The upstream part of the first main body structure and the midstream part of the first main body structure are respectively provided with the first pressure taking hole and the second pressure taking hole; The third pressure-taking hole is provided at the middle of the downstream part of the first main body structure and the upstream part of the second main body structure; The fourth pressure-taking hole and the fifth pressure-taking hole are respectively arranged at the midstream part of the second main body structure and the downstream part of the second main body structure; The first differential pressure sensor is located between the first pressure taking hole and the third pressure taking hole; The second differential pressure sensor is located between the third pressure taking hole and the fifth pressure taking hole.

8. The downhole gas flow testing device according to claim 7, characterized in that: The downhole gas flow testing device further comprises a first pressure sensor and a second pressure sensor, wherein: The first pressure sensor is disposed at the midstream portion of the first main structure; The second pressure sensor is disposed at the midstream portion of the second main body structure; The first pressure sensor and the second pressure sensor are both electrically connected to the circuit board.

9. The downhole gas flow testing device according to any one of claims 1 to 3, characterized in that: The downhole gas flow testing device further includes a temperature sensor, which is disposed on the testing body and is electrically connected to the circuit board.

10. The downhole gas flow testing device according to any one of claims 1 to 3, characterized in that: The downhole gas flow testing device also includes a centralizer, wherein: The centralizer is connected to the outer wall of the test body and is located between the first body structure and the second body structure.

Images