Concentric double-channel gas well production pipe column for water-producing gas well and design method thereof

Abstract

The invention relates to the technical field of oil field drainage gas production, in particular to a concentric double-channel gas well production pipe column for a water-producing gas well and a design method of the concentric double-channel gas well production pipe column for the water-producing gas well, the concentric double-channel gas well production pipe column comprises a gas production tree, a casing pipe string, a large oil pipe string and a small oil pipe, and the gas production tree comprises a small oil pressure four-way joint, a large oil pressure four-way joint and a casing pressure four-way joint which are sequentially arranged from top to bottom; a main valve is connected in series on a connecting pipe communicated between the small oil pressure four-way joint and the large oil pressure four-way joint; the method comprises the following steps: (1) determining the size of a sleeve string; the gas production tree is reasonable and compact in structure and ingenious in conception, and is provided with the casing pipe string, the large oil pipe and the small oil pipe, so that the gas production tree is provided with three production channels during production operation; by arranging an O-shaped sealing ring, the independence of a central channel of the small oil pipe and an annular channel between the large oil pipe and the small oil pipe is guaranteed; by arranging the power device, the power device can be started to drain water when water produced by the high-water-yield gas well is higher than accumulated liquid of a shaft, and the device has the advantages of being reliable, stable and efficient.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield drainage and gas production, and is a concentric double-channel gas well production pipe column for water-producing gas wells and a design method thereof. Background Art

[0002] In the field of gas field production, the reasonable production string of gas wells is to replace it with the change of gas well production capacity and water-gas ratio. However, in the development process of low-permeability water-producing gas reservoirs, the configuration of gas well production strings failed to fully meet the needs of gas well production. This is because in the middle and late stages of gas well production, it is usually necessary to use well pressure to replace the production string of gas wells. Because low-permeability water-producing gas wells are sensitive to formation pressure and water-sensitive effects, well pressure will cause irreversible damage to the gas well. After well pressure and string replacement, nitrogen gas lift and drainage are generally used to assist gas well recovery. However, the recovery rate of gas wells is extremely low, so the replacement rate of production strings in the production process of low-permeability gas wells is also very low. Usually, a production string of one size is used to go through most stages of the gas well life cycle. This gas well production mode will lead to liquid accumulation in the gas well production process, and even liquid accumulation and stop of spraying. Summary of the invention

[0003] The present invention provides a concentric dual-channel gas well production string for water-producing gas wells and a design method thereof, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problem of difficulty in replacing the string in existing low-permeability gas wells.

[0004] One of the technical solutions of the present invention is achieved through the following measures: a concentric dual-channel gas well production string for water-producing gas wells, including a gas production tree, a casing pipe string, a large oil pipe string and a small oil pipe, the gas production tree includes a small oil pressure four-way, a large oil pressure four-way and a casing pressure four-way arranged in sequence from top to bottom, a main valve is connected in series to the connecting pipe between the small oil pressure four-way and the large oil pressure four-way, a first production valve is connected in series to the right connecting pipe of the small oil pressure four-way, a second production valve is connected in series to the right connecting pipe of the large oil pressure four-way, and a third production valve is connected in series to the right connecting pipe of the casing pressure four-way; a casing pipe string is suspended and installed in the lower connecting pipe of the casing pressure four-way, and a casing pipe string is provided in the casing pressure four-way. A large oil pipe string with an upper end located above it and suspended in the lower side pipe of the large oil pressure four-way, the large oil pipe string is provided with a small oil pipe with an upper end located above it and suspended in the lower side pipe of the lower oil pressure four-way; the large oil pipe string includes a conversion short-circuit and several large oil pipes, a conversion short-circuit is fixedly installed between the large oil pipe located at the top and the large oil pipe below it, a socket blind hole is provided in the center of the upper side of the conversion short-circuit, the lower end of the small oil pipe is inserted in the socket blind hole, a diversion inclined hole is provided on the outer side of the lower part of the conversion short-circuit, the upper side of the conversion short-circuit corresponding to the outer side of the socket blind hole is provided with a plurality of diversion straight holes that pass through from top to bottom at intervals along the circumference.

[0005] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: The above may also include a first production pipeline, a second production pipeline, a third production pipeline and a needle valve, the first production pipeline is fixedly connected between the first production valve and the needle valve, the second production pipeline is fixedly connected between the second production valve and the first production pipeline, and the third production pipeline is fixedly connected between the third production valve and the second production pipeline.

[0006] The above may also include a first backup valve, a second backup valve and a third backup valve, the main valve includes a first main valve and a second main valve connected in series, the first backup valve is connected in series to the upper side pipe of the small oil pressure four-way, the second backup valve is connected in series to the left side pipe of the large oil pressure four-way, the third backup valve is connected in series to the left side pipe of the sleeve pressure four-way, the first main valve, the second main valve, the first production valve, the second production valve, the third production valve, the first backup valve, the second backup valve and the third backup valve are all gate valves.

[0007] The above may also include a pressure gauge, and the first spare valve, the second spare valve and the third spare valve are all provided with a pressure gauge.

[0008] The above-mentioned device may also include an O-shaped sealing ring, and at least one O-shaped sealing ring is provided between the small oil pipe and the conversion short circuit at an interval above and below.

[0009] The above-mentioned large oil pipe string may also include a power device, which is fixedly installed between the large oil pipe at the position below the corresponding conversion short circuit and the large oil pipe below it, and the power device is a screw pump or an electric submersible pump.

[0010] The second technical solution of the present invention is achieved by the following measures: a design method of a concentric dual-channel gas well production string for a water-producing gas well using the above-mentioned concentric dual-channel gas well production string comprises the following steps: (1) The dimensions of the casing string include φ1 and φ2, where φ1=177.8mm and φ2=139.7mm; (2) If the casing string size is φ1, it includes: M1: The size of the large oil pipe is φ3, and the size of the small oil pipe is φ4, where φ3=73mm, φ4=48mm. At this time, the annular channel between the casing string and the large oil pipe is A1, and the area of ​​A1 is S1. The annular channel between the large oil pipe and the small oil pipe is B1, and the area of ​​B1 is S2. The central channel of the small oil pipe is C1, and the area of ​​C1 is S3, where S1=14920.50mm 2 , S2=1208.90mm 2 , S3=1313.2mm 2 At this time, A1 is suitable for daily production greater than 50000m 3 Low-yield water gas well production, B1 is suitable for daily production between 4127m 3 Up to 50000m3 Low-yield water gas well production, in this case C1 is suitable for daily production greater than 4482m 3 Production from low-yield water gas wells; M2: The size of the large oil pipe is φ5, and the size of the small oil pipe is φ6, where φ5=89mm, φ6=48mm. At this time, the annular channel between the casing string and the large oil pipe is A2, and the area of ​​A2 is S4. The annular channel between the large oil pipe and the small oil pipe is B2, and the area of ​​B2 is S5. The central channel of the small oil pipe is C2, and the area of ​​C2 is S6, where S4=12885.78mm 2 , S5=2725.52mm 2 , S6=1313.2mm 2 At this time, A2 is suitable for daily production greater than 30,000m 3 Low-yield water gas well production, B2 is suitable for daily production between 9302m 3 Up to 30000m 3 Low-yield water gas well production, C2 is suitable for daily production greater than 4482m 3 Production from low-yield water gas wells; M3: The size of the large oil pipe is φ7, and the size of the small oil pipe is φ8, where φ7=101.3mm, φ8=60.3mm. At this time, the annular channel between the casing string and the large oil pipe is A3, and the area of ​​A3 is S7. The annular channel between the large oil pipe and the small oil pipe is B3, and the area of ​​B3 is S8. The central channel of the small oil pipe is C3, and the area of ​​C3 is S9, where S7=3437.76mm 2 , S8=3307.89mm 2 , S9=2015.40mm 2 At this time, A3 is suitable for daily production greater than 20,000m 3 Low-yield water gas well production, B3 is suitable for daily production between 11518m 3 Up to 20000m 3 Low-yield water gas well production, C3 is suitable for daily production of more than 7016m 3 Production from low-yield water gas wells; (3) If the casing string size is φ2, it includes: N1: The size of the large oil pipe is φ9, and the size of the small oil pipe is φ 10 , where φ9=73mm, φ 10 =48mm, at this time the annular channel between the casing string and the large oil pipe is A4, and the area of ​​A4 is S 10 , the annular channel between the large oil pipe and the small oil pipe is B4, and the area of ​​B4 is S 11 , the central channel of the small oil pipe is C4, and the area of ​​C4 is S 12 , where S 10 =7309.92mm2 , S 11 =1083.97mm 2 , S 12 =1313.20mm 2 At this time, A4 is suitable for daily production greater than 25000m 3 Low-yield water gas well production, B4 is suitable for daily production between 3700m 3 Up to 25000m 3 Low-yield water gas well production, C4 is suitable for daily production greater than 4482m 3 Production from low-yield water gas wells; N2: The size of the large oil pipe is φ 11 , the size of the small oil pipe is φ 12 , where φ 11 =73mm,φ 12 =42.16mm, at this time the annular channel between the casing string and the large oil pipe is A5, and the area of ​​A5 is S 13 , the annular channel between the large oil pipe and the small oil pipe is B5, and the area of ​​B5 is S 14 , the central channel of the small oil pipe is C5, and the area of ​​C5 is S 15 , where S 13 =7309.92mm 2 , S 14 =1622.23mm 2 , S 15 =964mm 2 At this time, A5 is suitable for daily production greater than 25000m 3 Low-yield water gas well production, B5 is suitable for daily production between 5537m 3 Up to 25000m 3 Low-yield water gas well production, C5 is suitable for daily production greater than 3301m 3 Production from low-yield water gas wells.

[0011] The third technical solution of the present invention is achieved by the following measures: a design method of a concentric dual-channel gas well production string for a water-producing gas well using the above-mentioned concentric dual-channel gas well production string comprises the following steps: 1) The dimensions of the casing string include D1 and D2, where D1=177.8mm and D2=139.7mm; 2) If the casing string size is D1, it includes: P1: The size of the large oil pipe is D3, and the size of the small oil pipe is D4, where D3=73mm, D4=48mm. At this time, the annular channel between the casing string and the large oil pipe is X1, and the area of ​​X1 is G1. The annular channel between the large oil pipe and the small oil pipe is Y1, and the area of ​​Y1 is G2. The central channel of the small oil pipe is Z1, and the area of ​​Z1 is G3, where G1=14920.50mm2 , G2=1208.90mm 2 , G3=1313.2mm 2 When the daily production of high-yield water-gas wells exceeds 4482m 3 When the gas well produces water higher than the wellbore liquid, the power unit is started and Y1 is used to drain water; P2: The size of the large oil pipe is D5, and the size of the small oil pipe is D6, where D5=89mm, D6=48mm. At this time, the annular channel between the casing string and the large oil pipe is X2, and the area of ​​X2 is G4. The annular channel between the large oil pipe and the small oil pipe is Y2, and the area of ​​Y2 is G5. The central channel of the small oil pipe is Z2, and the area of ​​Z2 is G6, where G4=12885.78mm 2 , G5=2725.52mm 2 , G6=1313.2mm 2 When the daily production of high-yield water-gas wells exceeds 4482m 3 When the gas well produces water higher than the wellbore liquid, the power unit is started and Y2 is used to drain water; P3: The size of the large oil pipe is D7, and the size of the small oil pipe is D8, where D7=101.3mm, D8=60.3mm. At this time, the annular channel between the casing string and the large oil pipe is X3, and the area of ​​X3 is G7. The annular channel between the large oil pipe and the small oil pipe is Y3, and the area of ​​Y3 is G8. The central channel of the small oil pipe is Z3, and the area of ​​Z3 is G9, where G7=3437.76mm 2 , G8=3307.89mm 2 , G9=2015.40mm 2 When the daily production of high-yield water-gas wells exceeds 7016m 3 When the gas well produces water higher than the wellbore liquid, the power unit is started and Y3 is used to drain water; 3) If the casing string size is D2, it includes: Q1: The size of the large oil pipe is D9, and the size of the small oil pipe is D 10 , where D9=73mm, D 10 =48mm, at this time the annular channel between the casing string and the large oil pipe is X4, and the area of ​​X4 is G 10 The annular channel between the large oil pipe and the small oil pipe is Y4, and the area of ​​Y4 is G 11 , the central channel of the small oil pipe is Z4, and the area of ​​Z4 is G 12 , where G 10 =7309.92mm 2 , G 11 =1083.97mm 2 , G 12=1313.20mm 2 When the daily production of high-yield water-gas wells exceeds 4482m 3 When the gas well produces water higher than the wellbore liquid, the power unit is started and Y4 is used to drain water; Q2: The size of the large oil pipe is D 11 , the size of the small oil pipe is D 12 , where D 11 =73mm, D 12 =42.16mm, at this time the annular channel between the casing string and the large oil pipe is X5, and the area of ​​X5 is G 13 The annular channel between the large oil pipe and the small oil pipe is Y5, and the area of ​​Y5 is G 14 , the central channel of the small oil pipe is Z5, and the area of ​​Z5 is G 15 , where G 13 =7309.92mm 2 , G 14 =1622.23mm 2 , G 15 =964mm 2 When the daily production of high-yield water-gas wells is greater than 3301m 3 When the gas well produces water higher than the liquid in the wellbore, the power unit is started and Y5 is used to drain water.

[0012] The present invention has a reasonable and compact structure and an ingenious design. By arranging a casing string, a large oil pipe and a small oil pipe, the gas tree has three production channels when performing production operations. By arranging an O-ring, the independence of the central channel of the small oil pipe and the annular channel between the large oil pipe and the small oil pipe is guaranteed. By arranging a power device, when the water production of a high-yield water gas well exceeds the liquid accumulation in the wellbore, the power device can be started to drain water, and the invention has the characteristics of reliability, stability and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Attached Figure 1 It is a schematic diagram of the main structure of embodiments 1 to 5 and 7.

[0014] Attached Figure 2 It is a schematic diagram of the main structure of Examples 6 and 8.

[0015] Attached Figure 3 For attachment Figure 1 Schematic diagram of the main cross-sectional structure of the intermediate conversion short circuit.

[0016] The codes in the attached drawings are: 1 for small oil pressure four-way valve, 2 for large oil pressure four-way valve, 3 for casing pressure four-way valve, 4 for the first main valve, 5 for the second main valve, 6 for the first production valve, 7 for the second production valve, 8 for the third production valve, 9 for the first spare valve, 10 for the second spare valve, 11 for the third spare valve, 12 for the needle valve, 13 for the first production pipeline, 14 for the second production pipeline, 15 for the third production pipeline, 16 for the casing pipe string, 17 for the large oil pipe, 18 for the small oil pipe, 19 for the conversion short circuit, 20 for the socket blind hole, 21 for the diversion inclined hole, 22 for the diversion straight hole, 23 for the O-ring, 24 for the power unit, and 25 for the pressure gauge. DETAILED DESCRIPTION

[0017] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0018] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached Figure 1 The layout is described in detail, such as the positional relationship of front, back, top, bottom, left, right, etc., which is based on the attached manual. Figure 1 It is determined by the layout direction.

[0019] The present invention will be further described below in conjunction with embodiments and drawings: Embodiment 1: As attached Figure 1 , 3As shown, the concentric dual-channel gas well production string for water-producing gas wells includes a gas production tree, a casing pipe string 16, a large oil pipe string and a small oil pipe 18. The gas production tree includes a small oil pressure four-way 1, a large oil pressure four-way 2 and a casing pressure four-way 3 arranged in sequence from top to bottom. A main valve is connected in series to the connecting pipe between the small oil pressure four-way 1 and the large oil pressure four-way 2. A first production valve 6 is connected in series to the right connecting pipe of the small oil pressure four-way 1, a second production valve 7 is connected in series to the right connecting pipe of the large oil pressure four-way 2, and a third production valve 8 is connected in series to the right connecting pipe of the casing pressure four-way 3; a casing pipe string 16 is suspended in the lower connecting pipe of the casing pressure four-way 3, and a casing pipe string 16 is provided with an upper end located above it and the upper end is suspended on the large oil pressure four A large oil pipe string in the lower side connecting pipe of the through 2 is provided in the large oil pipe string with a small oil pipe 18 whose upper end is located above it and whose upper end is suspended in the lower side connecting pipe of the lower oil pressure four-way; the large oil pipe string includes a conversion short circuit 19 and a plurality of large oil pipes 17, a conversion short circuit 19 is fixedly installed between the large oil pipe 17 located at the top and the large oil pipe 17 located below it, a socket blind hole 20 is provided in the center of the upper side of the conversion short circuit 19, the lower end of the small oil pipe 18 is inserted into the socket blind hole 20, and a diversion inclined hole 21 whose upper end can be connected with the socket blind hole 20 is provided on the outer side of the lower part of the conversion short circuit 19, and a plurality of diversion straight holes 22 that pass through from top to bottom are provided along the circumference at intervals on the upper side of the conversion short circuit 19 provided on the outer side of the socket blind hole 20. During use, by setting the casing string 16, the large oil pipe 17 and the small oil pipe 18, the gas tree has three production channels when performing production operations, which can be selected according to different gas production conditions, effectively solving the problem of difficulty in replacing the pipe string in the existing low-permeability gas wells. It can not only discharge the accumulated liquid in the wellbore of the liquid-accumulated gas well, but also replace the production channel in time according to the changes in the production dynamics of the gas well, thereby effectively avoiding the damage to the gas well caused by well pressure and realizing the effective use of the gas well production capacity. The above three channels are: (1) the first channel: the central channel of the small oil pipe 18, which can achieve production through the first production valve 6; (2) the second channel: the annular channel between the large oil pipe 17 and the small oil pipe 18, which can achieve production through the second production valve 7; (3) the third channel: the annular channel between the casing string 16 and the large oil pipe string, which can achieve production through the third production valve 8.

[0020] According to actual needs, the above-mentioned concentric dual-channel gas well production string for water-producing gas wells can be further optimized and / or improved: Embodiment 2: As attached Figure 1 , 3As shown, it also includes a first production pipeline 13, a second production pipeline 14, a third production pipeline 15 and a needle valve 12. The first production pipeline 13 is fixedly connected between the first production valve 6 and the needle valve 12, the second production pipeline 14 is fixedly connected between the second production valve 7 and the first production pipeline 13, and the third production pipeline 15 is fixedly connected between the third production valve 8 and the second production pipeline 14. During use, by setting up multiple production pipelines, different channels can be used to complete production under different working conditions.

[0021] Embodiment 3: As attached Figure 1 , 3 As shown, it also includes a first spare valve 9, a second spare valve 10 and a third spare valve 11. The main valve includes a first main valve 4 and a second main valve 5 connected in series. The first spare valve 9 is connected in series to the upper side pipe of the small oil pressure four-way 1, the second spare valve 10 is connected in series to the left pipe of the large oil pressure four-way 2, and the third spare valve 11 is connected in series to the left pipe of the sleeve pressure four-way 3. The first main valve 4, the second main valve 5, the first production valve 6, the second production valve 7, the third production valve 8, the first spare valve 9, the second spare valve 10 and the third spare valve 11 are all gate valves. In the process of use, through such a setting, each production valve can be used in one spare.

[0022] Embodiment 4: As attached Figure 1 , 3 As shown, a pressure gauge 25 is also included. The first backup valve 9, the second backup valve 10 and the third backup valve 11 are all provided with a pressure gauge 25. During use, the stability and safety of the gas tree are improved by providing the pressure gauge 25.

[0023] Embodiment 5: As attached Figure 1 , 3 As shown, an O-ring 23 may also be included, and at least one O-ring 23 is provided between the small oil pipe 18 and the conversion short circuit 19. During use, the O-ring 23 is provided to ensure the independence of the central channel of the small oil pipe 18 and the annular channel between the large oil pipe 17 and the small oil pipe 18.

[0024] Embodiment 6: As attached Figure 2 , 3 As shown, the large oil pipe string also includes a power device 24, and the power device 24 is fixedly installed between the large oil pipe 17 at the position below the corresponding conversion short circuit 19 and the large oil pipe 17 below it. The power device 24 is a screw pump or an electric submersible pump. During use, by setting the power device 24, when the water production of the high-yield water and gas well is higher than the wellbore liquid accumulation, the power device 24 can be started to drain water.

[0025] Embodiment 7: As attached Figure 1 , 3As shown, a design method for a concentric dual-channel gas well production string for a water-producing gas well includes the following steps: (1) The dimensions of the casing string 16 include φ1 and φ2, where φ1=177.8 mm and φ2=139.7 mm; (2) If the size of the casing string 16 is φ1, it includes: M1: The size of the large oil pipe 17 is φ3, and the size of the small oil pipe 18 is φ4, where φ3=73mm, φ4=48mm. At this time, the annular channel between the casing string 16 and the large oil pipe 17 is A1, and the area of ​​A1 is S1. The annular channel between the large oil pipe 17 and the small oil pipe 18 is B1, and the area of ​​B1 is S2. The central channel of the small oil pipe 18 is C1, and the area of ​​C1 is S3, where S1=14920.50mm 2 , S2=1208.90mm 2 , S3=1313.2mm 2 At this time, A1 is suitable for daily production greater than 50,000m 3 Low-yield water gas well production, B1 is suitable for daily production between 4127m 3 Up to 50000m 3 Low-yield water gas well production, in this case C1 is suitable for daily production greater than 4482m 3 Production from low-yield water gas wells; M2: The size of the large oil pipe 17 is φ5, and the size of the small oil pipe 18 is φ6, where φ5=89mm, φ6=48mm. At this time, the annular channel between the casing string 16 and the large oil pipe 17 is A2, and the area of ​​A2 is S4. The annular channel between the large oil pipe 17 and the small oil pipe 18 is B2, and the area of ​​B2 is S5. The central channel of the small oil pipe 18 is C2, and the area of ​​C2 is S6, where S4=12885.78mm 2 , S5=2725.52mm 2 , S6=1313.2mm 2 At this time, A2 is suitable for daily production greater than 30,000m 3 Low-yield water gas well production, B2 is suitable for daily production between 9302m 3 Up to 30000m 3 Low-yield water gas well production, C2 is suitable for daily production greater than 4482m 3 Production from low-yield water gas wells; M3: The size of the large oil pipe 17 is φ7, and the size of the small oil pipe 18 is φ8, where φ7=101.3mm, φ8=60.3mm. At this time, the annular channel between the casing string 16 and the large oil pipe 17 is A3, and the area of ​​A3 is S7. The annular channel between the large oil pipe 17 and the small oil pipe 18 is B3, and the area of ​​B3 is S8. The central channel of the small oil pipe 18 is C3, and the area of ​​C3 is S9, where S7=3437.76mm 2 , S8=3307.89mm 2 , S9=2015.40mm 2 At this time, A3 is suitable for daily production greater than 20,000m 3 Low-yield water gas well production, B3 is suitable for daily production between 11518m 3 Up to 20000m 3 Low-yield water gas well production, C3 is suitable for daily production of more than 7016m 3 Production from low-yield water gas wells; (3) If the size of the casing string 16 is φ2, it includes: N1: The size of the large oil pipe 17 is φ9, and the size of the small oil pipe 18 is φ 10 , where φ9=73mm, φ 10 =48mm, at this time the annular channel between the casing string 16 and the large oil pipe 17 is A4, and the area of ​​A4 is S 10 The annular channel between the large oil pipe 17 and the small oil pipe 18 is B4, and the area of ​​B4 is S 11 , the central channel of the small oil pipe 18 is C4, and the area of ​​C4 is S 12 , where S 10 =7309.92mm 2 , S 11 =1083.97mm 2 , S 12 =1313.20mm 2 At this time, A4 is suitable for daily production greater than 25000m 3 Low-yield water gas well production, B4 is suitable for daily production between 3700m 3 Up to 25000m 3 Low-yield water gas well production, C4 is suitable for daily production greater than 4482m 3 Production from low-yield water gas wells; N2: The size of the large oil pipe 17 is φ 11 , the size of the small oil pipe 18 is φ 12 , where φ 11 =73mm,φ 12 =42.16mm, at this time the annular channel between the casing string 16 and the large oil pipe 17 is A5, and the area of ​​A5 is S 13The annular channel between the large oil pipe 17 and the small oil pipe 18 is B5, and the area of ​​B5 is S 14 The central channel of the small oil pipe 18 is C5, and the area of ​​C5 is S 15 , where S 13 =7309.92mm 2 , S 14 =1622.23mm 2 , S 15 =964mm 2 At this time, A5 is suitable for daily production greater than 25000m 3 Low-yield water gas well production, B5 is suitable for daily production between 5537m 3 Up to 25000m 3 Low-yield water gas well production, C5 is suitable for daily production greater than 3301m 3 Production from low-yield water gas wells.

[0026] During implementation, when low-water-yield gas wells are produced, different production channels can be selected according to the sizes of the casing string 16, the large oil pipe 17 and the small oil pipe 18 and the daily production.

[0027] Embodiment 8: As attached Figure 2 , 3 As shown, a design method for a concentric dual-channel gas well production string for a water-producing gas well includes the following steps: 1) The dimensions of the casing string 16 include D1 and D2, where D1=177.8mm and D2=139.7mm; 2) If the size of the casing string 16 is D1, it includes: P1: The size of the large oil pipe 17 is D3, and the size of the small oil pipe 18 is D4, where D3=73mm, D4=48mm. At this time, the annular channel between the casing string 16 and the large oil pipe 17 is X1, and the area of ​​X1 is G1. The annular channel between the large oil pipe 17 and the small oil pipe 18 is Y1, and the area of ​​Y1 is G2. The central channel of the small oil pipe 18 is Z1, and the area of ​​Z1 is G3, where G1=14920.50mm 2 , G2=1208.90mm 2 , G3=1313.2mm 2 When the daily production of high-yield water-gas wells exceeds 4482m 3 When the water produced by the gas well is higher than the liquid in the wellbore, the power device 24 is started and the water is discharged by Y1; P2: The size of the large oil pipe 17 is D5, and the size of the small oil pipe 18 is D6, where D5=89mm, D6=48mm. At this time, the annular channel between the casing string 16 and the large oil pipe 17 is X2, and the area of ​​X2 is G4. The annular channel between the large oil pipe 17 and the small oil pipe 18 is Y2, and the area of ​​Y2 is G5. The central channel of the small oil pipe 18 is Z2, and the area of ​​Z2 is G6, where G4=12885.78mm 2 , G5=2725.52mm 2 , G6=1313.2mm 2 When the daily production of high-yield water-gas wells exceeds 4482m 3 When the gas well produces water higher than the wellbore liquid accumulation, the power device 24 is started and the water is discharged by Y2; P3: The size of the large oil pipe 17 is D7, and the size of the small oil pipe 18 is D8, where D7=101.3mm, D8=60.3mm. At this time, the annular channel between the casing string 16 and the large oil pipe 17 is X3, and the area of ​​X3 is G7. The annular channel between the large oil pipe 17 and the small oil pipe 18 is Y3, and the area of ​​Y3 is G8. The central channel of the small oil pipe 18 is Z3, and the area of ​​Z3 is G9, where G7=3437.76mm 2 , G8=3307.89mm 2 , G9=2015.40mm 2 When the daily production of high-yield water-gas wells exceeds 7016m 3 When the gas well produces water higher than the wellbore liquid accumulation, the power device 24 is started and the water is discharged by Y3; 3) If the size of the casing string 16 is D2, it includes: Q1: The size of the large oil pipe 17 is D9, and the size of the small oil pipe 18 is D 10 , where D9=73mm, D 10 =48mm, at this time the annular channel between the casing string 16 and the large oil pipe 17 is X4, and the area of ​​X4 is G 10 The annular channel between the large oil pipe 17 and the small oil pipe 18 is Y4, and the area of ​​Y4 is G 11 The central channel of the small oil pipe 18 is Z4, and the area of ​​Z4 is G 12 , where G 10 =7309.92mm 2 , G 11 =1083.97mm 2 , G 12 =1313.20mm 2 When the daily production of high-yield water-gas wells exceeds 4482m 3 When the gas well produces water higher than the wellbore liquid accumulation, the power device 24 is started and the water is discharged by Y4; Q2: The size of the large oil pipe 17 is D 11 , the size of the small oil pipe 18 is D 12 , where D 11 =73mm, D 12 =42.16mm, at this time the annular channel between the casing string 16 and the large oil pipe 17 is X5, and the area of ​​X5 is G 13 The annular channel between the large oil pipe 17 and the small oil pipe 18 is Y5, and the area of ​​Y5 is G 14 , the central channel of the small oil pipe 18 is Z5, and the area of ​​Z5 is G 15 , where G 13 =7309.92mm 2 , G 14 =1622.23mm 2 , G 15 =964mm 2 When the daily production of high-yield water-gas wells is greater than 3301m 3 When the water produced by the gas well is higher than the liquid accumulation in the wellbore, the power unit 24 is started and the water is discharged by Y5.

[0028] During implementation, it can be used for production of high-yield water and gas wells, and different production channels and opening and closing of the power device 24 can be selected according to the sizes of the casing string 16, the large oil pipe 17 and the small oil pipe 18 and the daily output.

[0029] The above technical features constitute the best embodiment of the present invention, which has strong adaptability and best implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A concentric dual-channel gas well production string for water-producing gas wells, characterized in that The gas tree comprises a gas production tree, a casing pipe string, a large oil pipe string and a small oil pipe. The gas production tree comprises a small oil pressure four-way, a large oil pressure four-way and a casing pressure four-way arranged in sequence from top to bottom. A main valve is connected in series to the connecting pipe between the small oil pressure four-way and the large oil pressure four-way. A first production valve is connected in series to the right connecting pipe of the small oil pressure four-way. A second production valve is connected in series to the right connecting pipe of the large oil pressure four-way. A third production valve is connected in series to the right connecting pipe of the casing pressure four-way. A casing pipe string is suspended in the lower connecting pipe of the casing pressure four-way. A casing pipe string is provided in the casing pipe string with an upper end located above it and the upper end is suspended on the lower connecting pipe of the large oil pressure four-way. A large oil pipe string is provided in the large oil pipe string, and a small oil pipe is arranged in the large oil pipe string, the upper end of which is located above the small oil pipe and the upper end is suspended in the lower side connecting pipe of the lower oil pressure four-way. The large oil pipe string includes a conversion short-circuit and several large oil pipes. A conversion short-circuit is fixedly installed between the large oil pipe located at the top and the large oil pipe below it. A socket blind hole is provided in the center of the upper side of the conversion short-circuit, and the lower end of the small oil pipe is inserted into the socket blind hole. A diversion inclined hole whose upper end can be connected with the socket blind hole is provided on the outer side of the lower part of the conversion short-circuit, and a plurality of diversion straight holes that pass through from top to bottom are provided at intervals along the circumference on the upper side of the conversion short-circuit provided on the outer side of the socket blind hole.

2. The concentric dual-channel gas well production string for water-producing gas wells according to claim 1, characterized in that It also includes a first production pipeline, a second production pipeline, a third production pipeline and a needle valve. The first production pipeline is fixedly connected between the first production valve and the needle valve, the second production pipeline is fixedly connected between the second production valve and the first production pipeline, and the third production pipeline is fixedly connected between the third production valve and the second production pipeline.

3. The concentric dual-channel gas well production string for water-producing gas wells according to claim 1 or 2, characterized in that It also includes a first backup valve, a second backup valve and a third backup valve. The main valve includes a first main valve and a second main valve connected in series. The first backup valve is connected in series to the upper side pipe of the small oil pressure four-way, the second backup valve is connected in series to the left side pipe of the large oil pressure four-way, and the third backup valve is connected in series to the left side pipe of the sleeve pressure four-way. The first main valve, the second main valve, the first production valve, the second production valve, the third production valve, the first backup valve, the second backup valve and the third backup valve are all gate valves.

4. The concentric dual-channel gas well production string for water-producing gas wells according to claim 3, characterized in that It also includes a pressure gauge, and the first spare valve, the second spare valve and the third spare valve are all provided with a pressure gauge.

5. The concentric dual-channel gas well production string for water-producing gas wells according to claim 1, 2 or 4, characterized in that It also includes an O-shaped sealing ring. At least one O-shaped sealing ring is arranged at an interval between the small oil pipe and the conversion short circuit.

6. The concentric dual-channel gas well production string for water-producing gas wells according to claim 3, characterized in that It also includes an O-shaped sealing ring. At least one O-shaped sealing ring is arranged at an interval between the small oil pipe and the conversion short circuit.

7. The concentric dual-channel gas well production string for water-producing gas wells according to claim 1, 2, 4 or 6, characterized in that The large oil pipe string also includes a power device, which is fixedly installed between the large oil pipe at the position below the corresponding conversion short circuit and the large oil pipe below it. The power device is a screw pump or an electric submersible pump.

8. The concentric dual-channel gas well production string for water-producing gas wells according to claim 5, characterized in that The large oil pipe string also includes a power device, which is fixedly installed between the large oil pipe at the position below the corresponding conversion short circuit and the large oil pipe below it. The power device is a screw pump or an electric submersible pump.

9. A method for designing a concentric dual-channel gas well production string for a water-producing gas well according to any one of claims 1 to 6, characterized in that The steps include: (1) The dimensions of the casing string include φ1 and φ2, where φ1=177.8mm and φ2=139.7mm; (2) If the casing string size is φ1, it includes: M1: The size of the large oil pipe is φ3, and the size of the small oil pipe is φ4, where φ3=73mm, φ4=48mm. At this time, the annular channel between the casing string and the large oil pipe is A1, and the area of ​​A1 is S1. The annular channel between the large oil pipe and the small oil pipe is B1, and the area of ​​B1 is S2. The central channel of the small oil pipe is C1, and the area of ​​C1 is S3, where S1=14920.50mm 2 , S2=1208.90mm 2 , S3=1313.2mm 2 At this time, A1 is suitable for daily production greater than 50,000m 3 Low-yield water gas well production, B1 is suitable for daily production between 4127m 3 Up to 50000m 3 Low-yield water gas well production, in this case C1 is suitable for daily production greater than 4482m 3 Production from low-yield water gas wells; M2: The size of the large oil pipe is φ5, and the size of the small oil pipe is φ6, where φ5=89mm, φ6=48mm. At this time, the annular channel between the casing string and the large oil pipe is A2, and the area of ​​A2 is S4. The annular channel between the large oil pipe and the small oil pipe is B2, and the area of ​​B2 is S5. The central channel of the small oil pipe is C2, and the area of ​​C2 is S6, where S4=12885.78mm 2 , S5=2725.52mm 2 , S6=1313.2mm 2 At this time, A2 is suitable for daily production greater than 30,000m 3 Low-yield water gas well production, B2 is suitable for daily production between 9302m 3 Up to 30000m 3 Low-yield water gas well production, C2 is suitable for daily production greater than 4482m 3 Production from low-yield water gas wells; M3: The size of the large oil pipe is φ7, and the size of the small oil pipe is φ8, where φ7=101.3mm, φ8=60.3mm. At this time, the annular channel between the casing string and the large oil pipe is A3, and the area of ​​A3 is S7. The annular channel between the large oil pipe and the small oil pipe is B3, and the area of ​​B3 is S8. The central channel of the small oil pipe is C3, and the area of ​​C3 is S9, where S7=3437.76mm 2 , S8=3307.89mm 2 , S9=2015.40mm 2 At this time, A3 is suitable for daily production greater than 20,000m 3 Low-yield water gas well production, B3 is suitable for daily production between 11518m 3 Up to 20000m 3 Low-yield water gas well production, C3 is suitable for daily production of more than 7016m 3 Production from low-yield water gas wells; (3) If the casing string size is φ2, it includes: N1: The size of the large oil pipe is φ9, and the size of the small oil pipe is φ 10 , where φ9=73mm, φ 10 =48mm, at this time the annular channel between the casing string and the large oil pipe is A4, and the area of ​​A4 is S 10 , the annular channel between the large oil pipe and the small oil pipe is B4, and the area of ​​B4 is S 11 , the central channel of the small oil pipe is C4, and the area of ​​C4 is S 12 , where S 10 =7309.92mm 2 , S 11 =1083.97mm 2 , S 12 =1313.20mm 2 At this time, A4 is suitable for daily production greater than 25000m 3 Low-yield water gas well production, B4 is suitable for daily production between 3700m 3 Up to 25000m 3 Low-yield water gas well production, C4 is suitable for daily production greater than 4482m 3 Production from low-yield water gas wells; N2: The size of the large oil pipe is φ 11 , the size of the small oil pipe is φ 12 , where φ 11 =73mm,φ 12 =42.16mm, at this time the annular channel between the casing string and the large oil pipe is A5, and the area of ​​A5 is S 13 , the annular channel between the large oil pipe and the small oil pipe is B5, and the area of ​​B5 is S 14 , the central channel of the small oil pipe is C5, and the area of ​​C5 is S 15 , where S 13 =7309.92mm 2 , S 14 =1622.23mm 2 , S 15 =964mm 2 At this time, A5 is suitable for daily production greater than 25000m 3 Low-yield water gas well production, B5 is suitable for daily production between 5537m 3 Up to 25000m 3 Low-yield water gas well production, C5 is suitable for daily production greater than 3301m 3 Production from low-yield water gas wells.

10. A method for designing a concentric dual-channel gas well production string for a water-producing gas well according to any one of claims 7 to 8, characterized in that The steps include: 1) The dimensions of the casing string include D1 and D2, where D1=177.8mm and D2=139.7mm; 2) If the casing string size is D1, include: P1: The size of the large oil pipe is D3, and the size of the small oil pipe is D4, where D3=73mm, D4=48mm. At this time, the annular channel between the casing string and the large oil pipe is X1, and the area of ​​X1 is G1. The annular channel between the large oil pipe and the small oil pipe is Y1, and the area of ​​Y1 is G2. The central channel of the small oil pipe is Z1, and the area of ​​Z1 is G3, where G1=14920.50mm 2 , G2=1208.90mm 2 , G3=1313.2mm 2 When the daily production of high-yield water-gas wells exceeds 4482m 3 When the gas well produces water higher than the wellbore liquid, the power unit is started and Y1 is used to drain water; P2: The size of the large oil pipe is D5, and the size of the small oil pipe is D6, where D5=89mm, D6=48mm. At this time, the annular channel between the casing string and the large oil pipe is X2, and the area of ​​X2 is G4. The annular channel between the large oil pipe and the small oil pipe is Y2, and the area of ​​Y2 is G5. The central channel of the small oil pipe is Z2, and the area of ​​Z2 is G6, where G4=12885.78mm 2 , G5=2725.52mm 2 , G6=1313.2mm 2 When the daily production of high-yield water-gas wells exceeds 4482m 3 When the gas well produces water higher than the wellbore liquid, the power unit is started and Y2 is used to drain water; P3: The size of the large oil pipe is D7, and the size of the small oil pipe is D8, where D7=101.3mm, D8=60.3mm. At this time, the annular channel between the casing string and the large oil pipe is X3, and the area of ​​X3 is G7. The annular channel between the large oil pipe and the small oil pipe is Y3, and the area of ​​Y3 is G8. The central channel of the small oil pipe is Z3, and the area of ​​Z3 is G9, where G7=3437.76mm 2 , G8=3307.89mm 2 , G9=2015.40mm 2 When the daily production of high-yield water-gas wells exceeds 7016m 3 When the gas well produces water higher than the wellbore liquid, the power unit is started and Y3 is used for drainage; 3) If the casing string size is D2, it includes: Q1: The size of the large oil pipe is D9, and the size of the small oil pipe is D 10 , where D9=73mm, D 10 =48mm, at this time the annular channel between the casing string and the large oil pipe is X4, and the area of ​​X4 is G 10 The annular channel between the large oil pipe and the small oil pipe is Y4, and the area of ​​Y4 is G 11 , the central channel of the small oil pipe is Z4, and the area of ​​Z4 is G 12 , where G 10 =7309.92mm 2 , G 11 =1083.97mm 2 , G 12 =1313.20mm 2 When the daily production of high-yield water-gas wells exceeds 4482m 3 When the gas well produces water higher than the wellbore liquid, the power unit is started and Y4 is used to drain water; Q2: The size of the large oil pipe is D 11 , the size of the small oil pipe is D 12 , where D 11 =73mm, D 12 =42.16mm, at this time the annular channel between the casing string and the large oil pipe is X5, and the area of ​​X5 is G 13 The annular channel between the large oil pipe and the small oil pipe is Y5, and the area of ​​Y5 is G 14 , the central channel of the small oil pipe is Z5, and the area of ​​Z5 is G 15 , where G 13 =7309.92mm 2 , G 14 =1622.23mm 2 , G 15 =964mm 2 When the daily production of high-yield water-gas wells is greater than 3301m 3 When the gas well produces water higher than the liquid in the wellbore, the power unit is started and Y5 is used for drainage.

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