Water injection and steam injection huff-puff collaborative oil extraction concentric pipe column and process method

Abstract

A water injection tubular column is installed in a sleeve, a water injection packer is arranged between the inner wall of the sleeve and the outer wall of the water injection tubular column, a steam injection tubular column is installed in the water injection tubular column, and the lower portion of the steam injection tubular column extends out of the bottom end of the water injection tubular column. A steam injection packer is arranged between the outer wall of the steam injection tubular column and the inner wall of the sleeve, the bottom of the steam injection tubular column is connected with a rod pump seat, and a pen point is installed at the bottom of the rod pump seat. A sucker rod is installed in the steam injection tubular column, the bottom of the sucker rod is connected with a rod pump, and the rod pump is installed on a rod pump base. By designing the water injection and steam injection huff and puff collaborative oil extraction concentric pipe column, water injection is carried out on a thin oil layer, steam huff and puff is carried out on a thick oil layer, and then pumping conversion production is carried out, so that two sets of different development layer series are used at the same time in one oil well, the well spacing number is reduced, and the block oil extraction speed is increased. Meanwhile, the tubular column further has a negative pressure oil extraction function, and the liquid production capacity of an oil well is improved.

Description

Technical Field

[0001] The present invention relates to a concentric pipe string and a process method for coordinated oil production by water injection and steam injection, in particular to a concentric pipe string and a process method for coordinated oil production by water injection and steam injection for multiple oil reservoirs with large oil layer spans and large differences in crude oil viscosity, which require multiple different development methods. Background Art

[0002] For multiple oil reservoirs with large spans and large differences in crude oil viscosity that require multiple different development methods, the current main method is to develop the layers separately. Among them, the thin oil reservoir is mainly developed by water injection, and the heavy oil reservoir is mainly developed by steam stimulation. The two layers are exploited separately at different stages and cannot be used at the same time. Therefore, a concentric pipe column and process method for coordinated oil production with water injection and steam stimulation are designed, and water injection is implemented in the thin oil layer and steam stimulation is performed on the heavy oil layer before switching to production, so that two different development layers can be used simultaneously in one oil well, reducing the number of wells and increasing the oil production rate of the block.

[0003] After reviewing the article "Application of Integrated Injection and Production Tubing in Ultra-Heavy Oil Wells" published in "Oil and Gas·Petroleum and Natural Gas Science" in 2021, a steam injection and oil production integrated tubing process emerged. This tubing only shortens the operation time from steam injection to pumping of ultra-heavy oil, and reduces the cold damage to the oil layer caused by well washing operations, but still cannot solve problems such as the simultaneous development and utilization of thin oil and heavy oil formations.

[0004] After checking the CN201910044009.5 patent "A horizontal well water injection and oil production integrated tubing and process method", an integrated water injection and oil production tubing appeared, but the tubing only achieved general water injection and combined oil production, and is only suitable for light oil water injection development. It still cannot solve the problem of steam injection and throughput in heavy oil layers and the simultaneous development of light oil and heavy oil according to different development methods.

[0005] After checking the CN201520211846.X patent "A pipe string for an integrated oil production and water injection process", an integrated oil production and water injection process pipe string appeared, but the pipe string only combines the oil production pipe string and the water injection pipe string into one, and the pipe string is only suitable for thin oil water injection development, and still cannot solve the problem of steam injection and huff and puff of heavy oil layers and the simultaneous exploitation of thin oil and heavy oil according to different development methods. Summary of the invention

[0006] In order to solve the problem that multiple layers cannot be simultaneously utilized according to different development methods, the present invention designs a concentric pipe string and process method for coordinated oil production by water injection and steam injection, respectively injecting water into the thin oil layer and performing steam injection and then switching to production in the heavy oil layer, so that two different development layers can be simultaneously utilized in one oil well, reducing the number of wells and increasing the oil production rate of the block.

[0007] In order to solve the above technical problems, the technical solution of the present invention is: a concentric pipe string for coordinated oil production with water injection and steam injection, including a casing, a water injection pipe string is installed in the casing, a water injection packer is provided between the inner wall of the casing and the outer wall of the water injection pipe string, a steam injection pipe string is installed in the water injection pipe string, the lower part of the steam injection pipe string extends out of the bottom end of the water injection pipe string, a steam injection packer is provided between the outer wall of the steam injection pipe string and the inner wall of the casing, the bottom of the steam injection pipe string is connected to a rod pump seat, and a pen tip is installed at the bottom of the rod pump seat; a sucker rod is installed in the steam injection pipe string, the bottom of the sucker rod is connected to a rod pump, and the rod pump is installed on the rod pump seat.

[0008] Further, the water injection packer is located above the water injection layer.

[0009] Furthermore, the steam injection packer is located between the water injection layer and the oil production layer.

[0010] Furthermore, the water injection string uses an insulated oil pipe.

[0011] A process for coordinated oil production by water injection and steam injection, having a concentric pipe column, comprises the following steps:

[0012] A. First, lower the steam injection string with the steam injection packer and the rod pump seat to the predetermined position and seal the steam injection packer;

[0013] B. Run the water injection string with the water injection packer to the predetermined position, seal the water injection packer and protect the casing;

[0014] C. Inject water into the thin oil injection layer through the water injection column;

[0015] D. Carry out steam injection and huff-and-puff in the heavy oil layer through the steam injection pipe column;

[0016] E. After the steam injection is completed, the sucker rod assembly with the rod pump is lowered into the steam injection string, and the well is opened for production.

[0017] Furthermore, water is injected into the thin oil injection layer according to the water injection requirements through the water injection string to replenish the formation energy and drive the thin oil to be produced from the corresponding oil well; the heat dissipated by the steam injection string can heat the injected water in the water injection string; at the same time, the steam entering the heavy oil layer can heat the upper water injection layer due to the overlying rise, further reduce the viscosity of the thin oil and improve the mobility ratio.

[0018] Furthermore, the steam injection column is used to steam the heavy oil layer according to the steam injection intensity, so as to heat the heavy oil layer and facilitate the flow of the heavy oil.

[0019] Furthermore, a sucker rod assembly with a rod pump is lowered into the steam injection string, and the well is opened for production; due to the presence of the steam injection packer, when the sucker rod assembly with a rod pump pumps up and down, negative pressure is formed near the rod pump seat, thereby improving the fluid supply capacity of the oil-producing layer.

[0020] The present invention designs a concentric pipe string for coordinated oil production with water injection and steam injection, so as to realize water injection for thin oil layers and steam injection for thick oil layers and then transfer to production, thereby realizing the simultaneous use of two different development layers in one oil well, reducing the number of wells and increasing the oil production rate of the block. At the same time, the pipe string also has a negative pressure oil production function to increase the liquid production of the oil well. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of a water injection-steam injection column;

[0022] Figure 2 It is a schematic diagram of the water injection-oil production string.

[0023] Among them: 1. Casing; 2. Steam injection string; 3. Water injection string; 4. Water injection packer; 5. Steam injection packer; 6. Rod pump seat; 7. Pen tip; 8. Sucker rod. DETAILED DESCRIPTION

[0024] The following is combined with Figure 1 , 2 The specific implementation modes of the present invention are further described.

[0025] A concentric pipe string for coordinated oil production with water injection and steam injection, comprising a casing 1, a water injection pipe string 3 is installed in the casing 1, a water injection packer 4 is arranged between the inner wall of the casing 1 and the outer wall of the water injection pipe string 3, a steam injection pipe string 2 is installed in the water injection pipe string 3, the lower part of the steam injection pipe string 2 extends out of the bottom end of the water injection pipe string 3, a steam injection packer 5 is arranged between the outer wall of the steam injection pipe string 2 and the inner wall of the casing 1, a rod pump seat 6 is connected to the bottom of the steam injection pipe string 2, and a pen tip 7 is installed at the bottom of the rod pump seat 6; a sucker rod 8 is installed in the steam injection pipe string 2, a rod pump is connected to the bottom of the sucker rod 8, and the rod pump is installed on the rod pump seat 6. The water injection packer 4 is located above the water injection layer, and the steam injection packer 5 is located between the water injection layer and the oil production layer.

[0026] A process for coordinated oil production by water injection and steam injection, having a concentric pipe column, comprises the following steps:

[0027] A. First, the steam injection string 2 with the steam injection packer 5 and the rod pump seat 6 is lowered to the predetermined position and the steam injection packer 5 is seated;

[0028] B. lowering the water injection string 3 with the water injection packer 4 to the predetermined position, sealing the water injection packer 4, and protecting the casing 1;

[0029] C. injecting water into the thin oil injection layer through the water injection column 3;

[0030] D. inject steam into the heavy oil layer through the steam injection column 2;

[0031] E. After the steam injection is completed, the sucker rod 8 with the rod pump is lowered into the steam injection string 2, and the well is opened for production.

[0032] The water injection string 3 is used to inject water into the thin oil injection layer according to the water injection requirements, replenishing the formation energy and driving the thin oil to be produced from the corresponding oil production well. The heat lost by the steam injection string 2 can heat the injected water in the water injection string 3; at the same time, the steam entering the heavy oil layer can heat the upper water injection layer due to the overlying rise, further reducing the viscosity of the thin oil and improving the mobility ratio.

[0033] The steam injection column 2 is used to inject steam into the heavy oil layer according to the steam injection intensity, so as to heat the heavy oil layer and facilitate the flow of the heavy oil.

[0034] The sucker rod 8 with a rod pump is lowered into the steam injection string 2 to start the well and pump out production. Due to the presence of the steam injection packer 5, when the sucker rod 8 with a rod pump is pumped up and down, negative pressure is formed near the rod pump seat 6, thereby improving the liquid supply capacity of the oil-producing layer.

[0035] The present invention adopts a concentric double-tube structure to respectively inject water and steam into the thin oil and heavy oil layers. The water injection string 3 adopts an insulated oil pipe, and the steam injection string 2 adopts a conventional oil pipe. The steam injection string 2 is preliminarily lowered into a rod pump seat 6. The thin oil and heavy oil layers are isolated by a lower packer, and a packer is lowered into the top of the thin oil layer to protect the casing 1. After the steam injection of the heavy oil layer is completed, the production stage is turned to the production stage, and the rod pump and the sucker rod 8 are directly lowered to carry out negative pressure oil production, thereby realizing the simultaneous development of water injection in the thin oil layer and steam injection in the heavy oil layer.

[0036] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A concentric pipe string for coordinated oil production by water injection and steam injection, characterized in that: The invention comprises a casing (1), a water injection pipe column (3) is installed in the casing (1), a water injection packer (4) is arranged between the inner wall of the casing (1) and the outer wall of the water injection pipe column (3), a steam injection pipe column (2) is installed in the water injection pipe column (3), the lower part of the steam injection pipe column (2) extends out of the bottom end of the water injection pipe column (3), a steam injection packer (5) is arranged between the outer wall of the steam injection pipe column (2) and the inner wall of the casing (1), the bottom of the steam injection pipe column (2) is connected to a rod pump seat (6), and a pen tip (7) is installed at the bottom of the rod pump seat (6); a sucker rod (8) is installed in the steam injection pipe column (2), the bottom of the sucker rod (8) is connected to a rod pump, and the rod pump is installed on the rod pump seat (6).

2. The water injection and steam injection huff and puff coordinated oil production concentric string according to claim 1, characterized in that: The water injection packer (4) is located above the water injection layer.

3. The water injection and steam injection huff and puff coordinated oil production concentric string according to claim 1, characterized in that: The steam injection packer (5) is located between the water injection layer and the oil production layer.

4. The water injection and steam injection huff and puff coordinated oil production concentric string according to claim 1, characterized in that: The water injection pipe column (3) adopts a heat-insulated oil pipe.

5. A process for coordinated oil production by water injection and steam injection, characterized in that: A concentric pipe column according to any one of claims 1 to 4, comprising the following steps: A. Firstly, the steam injection pipe column (2) with the steam injection packer (5) and the rod pump seat (6) is lowered to a predetermined position and the steam injection packer (5) is seated; B. lowering the water injection string (3) with the water injection packer (4) to a predetermined position, sealing the water injection packer (4) and protecting the casing (1); C. injecting water into the thin oil injection layer through the water injection column (3); D. injecting steam into the heavy oil layer through the steam injection column (2); E. After the steam injection is completed, the sucker rod (8) with the rod pump is lowered into the steam injection pipe column (2) to start the well pumping and production.

6. The process for coordinated oil production by water injection and steam injection huff and puff according to claim 5, characterized in that: In the step C, water is injected into the thin oil water injection layer through the water injection string (3) according to the water injection requirements, so as to replenish the formation energy and drive the thin oil to be produced from the corresponding oil production well; the heat dissipated by the steam injection string (2) can heat the injected water in the water injection string (3); at the same time, the steam entering the heavy oil layer can heat the upper water injection layer due to the overlying rise, thereby further reducing the viscosity of the thin oil and improving the mobility ratio.

7. The process for coordinated oil production by water injection and steam injection huff and puff according to claim 5, characterized in that: In the step D, steam is injected into and out of the heavy oil layer according to the steam injection intensity through the steam injection column (2), so as to heat the heavy oil layer and facilitate the flow of the heavy oil.

8. The process for coordinated oil production by water injection and steam injection huff and puff according to claim 5, characterized in that: In the step E, the sucker rod (8) with the rod pump is lowered into the steam injection column (2) to start the well and pump out the oil. Due to the presence of the steam injection packer (5), when the sucker rod (8) with the rod pump pumps up and down, negative pressure is formed near the rod pump seat (6), thereby improving the liquid supply capacity of the oil-producing layer.

Images