Integrated production pipe column of gas drive producing well and method of integrated production pipe column

Abstract

The invention relates to the field of oil production engineering equipment, in particular to an integrated production pipe column for a gas drive oil production well, which comprises a sleeve, an oil pipe is coaxially arranged in the sleeve, the bottom end of the oil pipe is in threaded connection with a horn mouth, and the oil pipe is fixedly connected with a pump support joint above the horn mouth. A gas lift working barrel is arranged at the top end of the pump supporting connector, and a delivery tool part is further arranged in the oil pipe. The tubular column and the method have the advantages that the tubular column and the method can be applied for a long time under different production conditions, the requirements of different yields and different gas-liquid ratios are met, the production tubular column can be repeatedly used, and the operation cost is saved.

Description

Technical Field

[0001] This application relates to the field of oil production engineering equipment, and in particular to an integrated production tubing string and method for gas-driven oil wells. Background Technology

[0002] During oilfield development, when the formation's energy is insufficient for self-flowing production, artificial energy supplementation is required. Different oilfields use different displacement energies, resulting in varying degrees of well exploitation. Waterflooding is a widely used method, employing water injection to replenish the formation's energy deficit and achieve water-driven oil production. However, a drawback is that increased water pressure and volume can easily lead to premature water breakthrough or flooding of high-permeability oil layers.

[0003] Gas-driven oil recovery technologies, such as those using carbon dioxide and natural gas, can achieve certain oil recovery results. Field experiments and applications have shown promising oil enhancement effects. Gas-driven oil recovery technology is maturing, especially in low-permeability reservoirs where it significantly improves effective utilization and single-well production. However, several challenges remain, one of which is the issue of production tubing in gas-driven wells.

[0004] The technologies related to gas-driven oil well lift tubing include three main types. The first is pump-driven production. However, once the gas drive becomes effective, the gas-liquid ratio increases, pump efficiency decreases, and in severe cases, gas lock occurs, leading to well shutdown and production stoppage. This requires venting the casing gas before resuming production, making continuous operation of the mechanically pumped well impossible and significantly reducing production uptime. The second type involves using pump-driven production tubing with gas-proofing tools and venting devices in the surface production process. This alleviates the problems of increased gas-liquid ratio, decreased pump efficiency, and gas lock to some extent, but gas lock and well shutdown issues still exist as gas production gradually increases. The third type is gas-lift production tubing, which avoids the impact of high gas-liquid ratios on the pump-driven lifting system. However, this type of tubing is not suitable for low-production oil wells and has low cost-effectiveness.

[0005] Chinese Patent: An Oil Production Tubing String and Application Method, Publication No.: CN106499347B. This application provides an oil production tubing string for high gas-liquid ratio oil wells. By adding a foaming device to the tubing, a foaming agent generates a large amount of foam that carries the crude oil from the bottom of the well. Under the lifting effect of the formation gas within the wellbore, the foam is lifted upwards along the wellbore to the surface. This tubing string fully utilizes the natural energy of the formation gas to achieve the lifting of the crude oil from the bottom of the well, avoiding the problems of low pump efficiency and no fluid output caused by the influence of formation gas during conventional rod pump oil production.

[0006] However, the production tubing in the above application has a single function and can only be used under high gas-liquid ratio conditions. Summary of the Invention

[0007] In order to meet the needs of production process tubing and methods for long-term application under different production conditions, and to meet the needs of different outputs and different gas-liquid ratios, and to enable the reuse of production tubing and save operating costs, this application provides an integrated production tubing and method for gas-driven oil wells.

[0008] This application provides an integrated production tubing string for gas-driven oil wells, employing the following technical solution:

[0009] An integrated production tubing string for gas-driven oil wells includes a casing, an oil pipe coaxially arranged inside the casing, a bell mouth threaded to the bottom end of the oil pipe, a pump support joint fixedly connected above the bell mouth of the oil pipe, an air lift working cylinder arranged at the top end of the pump support joint, and a delivery tool unit arranged inside the oil pipe.

[0010] Optionally, the air lift working cylinder includes a working cylinder, which is threadedly connected to the oil pipe. An air lift valve is fixedly connected inside the working cylinder, and the air lift valve controls the opening and closing of the working cylinder.

[0011] Optionally, when the pressure at the location of the air lift valve is greater than its set value, the air lift valve opens, and the annulus of the oil sleeve is connected to the oil pipe.

[0012] Optionally, the delivery tool includes a sucker rod located inside the oil pipe, and a sucker pump is fixedly connected to the sucker rod, with the sucker pump abutting and fixed to the pump support joint.

[0013] Optionally, the delivery tool includes a plunger that is slidably connected to the tubing. The plunger is located between the gas lift working cylinder and the pump support joint, and a downhole limiter is provided between the plunger and the pump support joint.

[0014] Optionally, the downhole limiter includes a locking device, and a buffer is provided at the top of the locking device, the outer diameter of which is smaller than the inner diameter of the tubing.

[0015] Optionally, the top and bottom ends of the plunger are respectively fixedly connected with elastic elements.

[0016] Optionally, the inner diameter of the air-lift working cylinder is the same as the inner diameter of the oil pipe.

[0017] This application also provides a gas-driven effective oil well production method, applied to the above-mentioned integrated production tubing for gas-driven oil wells, the method comprising: producing oil wells by lifting with a rod pump when the gas-driven production wells are ineffective.

[0018] S10: Connect the production tubing string, and sequentially connect the bell mouth, the pump support joint, the air lift working cylinder and the oil pipe from bottom to top along the height direction;

[0019] S11: Lowering the production tubing: Lower the production tubing into the casing to the predetermined position, and lower the sucker rod and pump to the pump support joint;

[0020] S12: Production commences.

[0021] Optionally, when the gas-driven production well is effective and the production volume and gas-liquid ratio are low, production can be carried out by plunger gas lift.

[0022] S20: Lift the rod column to remove the oil pump and sucker rod from the production tubing;

[0023] S21: Lower the downhole limiter, connect the fishing tool with the wire tool string and drop it to the designated position, then shake the tool string downwards to seal the downhole limiter;

[0024] S22: Engage the plunger;

[0025] S23: Production commenced;

[0026] In gas-driven production wells, the production of fluid and gas, as well as the gas-liquid ratio, gradually increase, with continuous gas lift production.

[0027] S30: Retrieve the downhole plunger and downhole limiter in sequence;

[0028] S31: Production commencement. In summary, this application includes at least one of the following beneficial technical effects:

[0029] 1. It is applicable to the lifting production tubing of oil wells in the gas drive block of the oilfield. It can adjust the lifting production mode according to different gas-liquid ratios in the well, avoid repeated tubing string tripping operations, extend production time, improve lifting efficiency, and save operating costs. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of an integrated production tubing for gas-driven oil wells under high production volume and low gas-oil ratio production conditions, as described in an embodiment of this application.

[0031] Figure 2 This is a schematic diagram of the structure of an integrated production tubing for gas-driven oil wells under production conditions of reduced fluid production and increased gas-oil ratio, as described in an embodiment of this application.

[0032] Figure 3 This is a schematic diagram of the structure of an integrated production tubing for gas-driven oil wells under high gas-oil ratio production conditions, as described in an embodiment of this application.

[0033] Explanation of reference numerals in the attached drawings: 1. Casing; 2. Tubing; 21. Bell mouth; 3. Pump support joint; 4. Gas lift working barrel; 5. Sucker rod; 51. Pumping pump; 6. Plunger; 61. Elastic element; 7. Downhole limiter. Detailed Implementation

[0034] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0035] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0036] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.

[0037] This application discloses an integrated production tubing string for gas-driven oil wells. (Refer to...) Figure 1-3 An integrated production tubing string for gas-driven oil wells includes a vertically arranged casing 1, an oil pipe 2 coaxially arranged inside the casing 1, and a bell mouth 21 threadedly connected to the bottom end of the oil pipe 2. The interior of the bell mouth 21 is in communication with the interior of the oil pipe 2. The bell mouth 21 is flared, and its diameter gradually decreases along the height direction from low to high, with the diameter of the top of the bell mouth 21 being the same as the diameter of the oil pipe 2.

[0038] A pump support joint 3 is fixedly connected to the tubing 2. The pump support joint 3 is used to support the pump body that extends into the tubing 2 later. The inner diameter of the pump support joint 3 is smaller than the outer diameter of the later oil pump 51, so that the oil pump 51, which extends into the well along with the sucker rod 5, is sealed and fixed through the pump support head.

[0039] An air-lift working cylinder 4 is also provided above the pump support joint 3. The top end of the air-lift working cylinder 4 is threadedly connected to the oil pipe 2 located at the upper part of the air-lift working cylinder 4, and the bottom end of the air-lift working cylinder 4 is threadedly connected to the oil pipe 2 located at the lower part of the air-lift working cylinder 4.

[0040] The gas lift working cylinder 4 includes an outer working cylinder and an air lift valve inside the working cylinder. The air lift valve is fixedly connected to the working cylinder and controls the opening and closing of the gas lift working cylinder 4. When the pressure value at the location of the air lift valve exceeds its set value, the air lift valve automatically opens, allowing gas in the annulus to enter the tubing 2 through the air lift valve, mix with the fluid in the tubing 2, reduce the fluid density, and lift the fluid in the tubing 2. The inner diameter of the gas lift working cylinder 4 is the same as the inner diameter of the tubing 2, and it is used for fluid injection into the tubing string and for subsequent insertion of testing instruments to test relevant formation parameters.

[0041] Reference Figure 1 , Figure 2Inside tubing 2, there is also a delivery tool unit. Depending on the production method, different delivery tools can be selected to enter the interior of tubing 2. The lifting production method is adjusted according to the different gas-liquid ratios in the well, and the downhole production string is formed according to the design requirements.

[0042] Reference Figure 1 In some embodiments, the delivery tool includes a vertically arranged sucker rod 5, which is coaxially arranged with the oil pipe 2, and a sucker pump 51 is installed on the sucker rod 5. The sucker pump 51 can be selected as a rod pump. The sucker rod 5 extends into the interior of the oil pipe 2, and the sucker rod 5 moves the sucker pump 51 to the position of the pump support joint 3. The pump support joint 3 fixes and seals the sucker pump 51.

[0043] Reference Figure 2 In some embodiments, the delivery tool includes a plunger 6, which is located inside the oil pipe 2 and between the lifting working cylinder and the pump support joint 3. The plunger 6 and the oil pipe 2 are slidably connected, and the plunger 6 can move vertically inside the oil pipe 2. The plunger 6 has a cylindrical structure, and elastic elements 61 are respectively provided at the top and bottom ends of the plunger 6. The elastic elements 61 can be spring sheets.

[0044] A downhole limiter 7 is installed between the plunger 6 and the pump support joint 3. The downhole limiter 7 is fixedly connected to the tubing 2 and is used to limit the downward movement of the plunger 6. The downhole limiter 7 includes a locking device at the bottom end, which is fixedly connected to the inner wall of the tubing 2. The locking device serves as the downward limit point for the plunger 6. A buffer is fixedly connected to the top end of the locking device. The outer diameter of the buffer is smaller than the inner diameter of the tubing 2 to prevent the plunger 6 from falling and impacting the locking device inside the tubing 2.

[0045] This application also discloses a gas-driven effective oil well production method, applied to the aforementioned integrated production tubing for gas-driven oil wells, the method comprising:

[0046] Reference Figure 1 When the gas-driven production well is ineffective, production is carried out by lifting with a rod pump. The tubing also includes a rod pump 51 and a sucker rod 5. The sucker rod 5 is connected to the rod pump from top to bottom, and the rod pump is placed in the pump support joint 3.

[0047] S10: Connect the production tubing string, and sequentially connect the bell mouth 21, the pump support joint 3, the air lift working cylinder 4 and the oil pipe 2 from bottom to top along the height direction;

[0048] S11: Lowering the production tubing: Lower the production tubing into the casing 1 to the predetermined position, and lower the sucker rod 5 and the oil pump 51 to the pump support joint 3;

[0049] S12: Production commences.

[0050] Reference Figure 2 When the gas-driven production well is effective and the production volume and gas-liquid ratio are small, production is carried out by the plunger 6 gas lift method. The tubing does not include the rod pump 51 and the sucker rod 5.

[0051] S20: Lift the rod column to remove the oil pump 51 and the sucker rod 5 from the production tubing;

[0052] S21: Lower downhole limiter 7, connect the fishing tool with a wire tool string and drop it to the designated position, and shake the tool string downwards to seal downhole limiter 7;

[0053] S22: Insert plunger 6;

[0054] S23: Production commenced.

[0055] Reference Figure 3 When the gas-driven production well is effective and the production of fluid and gas gradually increases, production is carried out using a continuous gas lift method:

[0056] S30: Sequentially retrieve the downhole plunger 6 and the downhole limiter 7;

[0057] S31: Production commenced.

[0058] In this invention, the term "multiple" refers to at least two or more, unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection 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.

[0059] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. An integrated production tubing string for gas-driven oil wells, characterized in that: It includes a casing (1), and an oil pipe (2) is coaxially arranged inside the casing (1). The bottom end of the oil pipe (2) is threaded with a bell mouth (21). A pump support joint (3) is fixedly connected above the bell mouth (21) of the oil pipe (2). An air lift working cylinder (4) is arranged at the top end of the pump support joint (3). A delivery tool part is also arranged inside the oil pipe (2).

2. The integrated production tubing for gas-driven oil wells according to claim 1, characterized in that: The air lift working cylinder (4) includes a working cylinder, which is threadedly connected to the oil pipe (2). An air lift valve is fixedly connected inside the working cylinder, and the air lift valve controls the opening and closing of the working cylinder.

3. The integrated production tubing for gas-driven oil wells according to claim 2, characterized in that: When the pressure at the location of the air lift valve is greater than its set value, the air lift valve opens, and the oil sleeve annulus is connected to the oil pipe (2).

4. The integrated production tubing for gas-driven oil wells according to claim 1, characterized in that: The delivery tool includes a sucker rod (5) located inside the oil pipe (2), and a sucker pump (51) is fixedly connected to the sucker rod (5). The sucker pump (51) is abutted and fixed to the pump support joint (3).

5. The integrated production tubing for gas-driven oil wells according to claim 1, characterized in that: The delivery tool includes a plunger (6), which is slidably connected to the tubing (2). The plunger (6) is located between the gas lift working cylinder (4) and the pump support joint (3). A downhole limiter (7) is provided between the plunger (6) and the pump support joint (3).

6. The integrated production tubing for gas-driven oil wells according to claim 5, characterized in that: The downhole limiter (7) includes a locking device, and a buffer is provided at the top of the locking device. The outer diameter of the buffer is smaller than the inner diameter of the tubing (2).

7. The integrated production tubing for gas-driven oil wells according to claim 5, characterized in that: The top and bottom ends of the plunger (6) are respectively fixedly connected to elastic elements (61).

8. The integrated production tubing for gas-driven oil wells according to claim 1, characterized in that: The inner diameter of the air-lift working cylinder (4) is the same as the inner diameter of the oil pipe (2).

9. A method for producing effective oil wells via gas drive, characterized in that, The method is applied to the integrated production tubing for gas-driven oil wells according to any one of claims 1-8, and includes: producing oil by lifting with a rod pump when the gas-driven production well is ineffective. S10: Connect the production tubing string and connect the bell mouth (21), the pump support joint (3), the air lift working cylinder (4) and the oil pipe (2) sequentially from bottom to top along the height direction; S11: Lower the production tubing: Lower the production tubing into the casing (1) to the predetermined position, and lower the sucker rod (5) and the oil pump (51) to the pump support joint (3); S12: Production commences.

10. The gas-driven effective oil well production method according to claim 9, characterized in that: When the gas-driven production well is effective and the production volume and gas-liquid ratio are small, production is carried out by plunger (6) gas lift method; S20: Lift the rod column to remove the oil pump (51) and sucker rod (5) from the production tubing; S21: Lower the downhole limiter (7), connect the fishing tool with the wire tool string and drop it to the designated position, shake the tool string downwards, and seal the downhole limiter (7); S22: Insert plunger (6); S23: Production commenced; In gas-driven production wells, the production of fluid and gas, as well as the gas-liquid ratio, gradually increase, with continuous gas lift production. S30: Sequentially retrieve the downhole plunger (6) and downhole limiter (7); S31: Production commenced.

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