Uniform steam injection oil extraction pipe column

Abstract

The invention discloses a uniform steam injection oil extraction pipe column which comprises an oil pipe, packers are arranged at the top and the bottom of each oil layer, the packers are located between the oil layers and a sleeve, the packers are fixedly connected with the oil pipe, one end of an adjusting screen pipe is connected with the packers, the other end of the adjusting screen pipe is connected with the oil pipe, an oil extraction valve is fixedly connected with the oil pipe, and a first screwed plug is installed at one end of the oil pipe. Oil layers are sleeved outside the oil pipe, and packers are arranged at the two ends of each oil layer; a first screwed plug is installed at one end of the oil pipe. According to the invention, the integration of injection and production is realized, the utilization time rate of an oil well is improved, the operation cost is reduced, and the adverse effect on the ground environment in the operation process is further reduced. Mutual interference between the high-pressure oil layer and the low-pressure oil layer in the oil extraction process is avoided, the reasonable steam injection amount of an oil reservoir is achieved, the oil reservoir development effect is greatly improved, and certain reference significance is achieved for development of complex oil reservoirs.

Description

Technical Field

[0001] The invention relates to the technical field of oil production engineering, and in particular to a uniform steam injection oil production pipe string. Background Art

[0002] At present, the production of heavy oil is mainly developed by steam injection. However, due to the development of oil reservoirs, the steam absorption capacity of oil reservoirs is uneven, which has an adverse effect on crude oil production. In order to change this situation, the main production method is currently stratified selection injection. However, its disadvantage is that it requires manual ball throwing, which has certain safety risks. In order to solve this problem, there is a patent number "201320099078.4" designed according to the steam absorption capacity of the oil reservoir, and the name is "seepage steam flow control device and thermal recovery steam injection string". Its principle is to use a double-layer slotted pipe according to the steam absorption capacity of each steam injection unit. The pipe wall of the slotted pipe is provided with multiple air-permeable slits. The slotted pipe sleeve is arranged outside the perforated central pipe to form an annular space. The annular space constitutes a filling cavity for filling particles. The screen pipes with different hole sizes are used for steam injection. This device can be used in two or more stages, according to the actual situation, but it cannot achieve stratified oil production, and another oil production string needs to be lowered. It does not use on-site production. Summary of the invention

[0003] The present invention solves the problem that the above-mentioned pipe string cannot be used in layers and needs another set of oil production pipe string, and provides a uniform steam injection oil production pipe string to achieve the purpose of implementing layered steam injection and layered oil production in one trip of the pipe string.

[0004] In order to solve the above technical problems, the technical solution of the present invention is: a uniform steam injection oil production pipe string, including an oil pipe, each oil layer is provided with a packer at the top and bottom, the packer is located between the oil layer and the casing, the packer is fixedly connected to the oil pipe, one end of the adjusting screen is connected to the packer, and the other end is connected to the oil pipe, the oil production valve is fixedly connected to the oil pipe, and a wire plug is installed at one end of the oil pipe.

[0005] Furthermore, the adjustable screen tube comprises an outer screen tube and an inner screen tube, a memory alloy screen tube and an elastic filler are arranged between the outer screen tube and the inner screen tube, and the two ends of the outer screen tube and the inner screen tube are respectively connected with an upper joint and a lower joint.

[0006] Furthermore, the oil production valve includes a body, one end of the body is provided with an internal thread, the other end is provided with an external thread, the body is connected with an oil inlet channel 1 and an oil inlet channel 2, one end of the oil inlet channel 1 is provided with a valve ball, and the other end is provided with a screw plug 2.

[0007] Furthermore, the lower part of the upper joint is machined with internal and external threads, and the upper part of the lower joint is machined with internal and external threads, and the outer diameter of the external thread is large, and the outer diameter of the internal thread is small.

[0008] Furthermore, the outer screen tube and the inner screen tube form a rigid mesh container.

[0009] Furthermore, the elastic filler is a mesh-shaped air-permeable material.

[0010] Furthermore, the memory alloy screen tube is a rolled structure, which is in a clamped state under a low temperature state and in an unfolded state under a steam injection state.

[0011] Furthermore, the outer wall of the memory alloy screen tube is fitted with the outer screen tube.

[0012] The present invention realizes the integration of injection and production, improves the utilization rate of oil wells, reduces operating costs, and further reduces the adverse impact on the ground environment during the operation process. It avoids the mutual interference between high-pressure and low-pressure oil layers during the oil production process, so that the oil reservoir has a reasonable amount of steam injection and the development effect of the oil reservoir has been greatly improved, which has certain reference significance for the development of complex oil reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the present invention or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 It is a schematic diagram of the present invention;

[0015] Figure 2 It is a schematic diagram of adjusting the screen tube;

[0016] Figure 3 It is the initial state diagram of the adjustment screen tube;

[0017] Figure 4 It is the state diagram of adjusting the steam injection of the screen tube;

[0018] Figure 5 Schematic diagram of oil production valve.

[0019] Among them: 1. Packer 1; 2. Packer 2; 3. Packer 3; 4. Packer 4; 5. Adjustment screen 1; 6. Adjustment screen 2; 7. Adjustment screen 3; 8. Production valve 1; 9. Production valve 2; 10. Production valve 3; 11. Plug 1; 12. Oil layer 1; 13. Oil layer 2; 14. Oil layer 3; 15. Oil pipe; 5-1. Upper joint; 5-2. Outer screen; 5-3. Inner screen; 5-4. Memory alloy screen; 5-5. Elastic filler; 5-6. Lower joint; 8-1. Main body; 8-2. Plug 2; 8-3. Valve ball; 8-4. Oil inlet channel 2; 8-5. Oil inlet channel 1. DETAILED DESCRIPTION

[0020] The following will be combined with the attached Figure 1-5 The technical solution of the present invention is described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The present invention is described in detail below by specific examples, but the protection scope of the present invention is not limited. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels.

[0022] In the description of the present invention, it should be noted that the terms "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are only used for distinction, and cannot be understood as indicating or implying relative importance.

[0023] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] A uniform steam injection oil production pipe string includes an oil pipe 15. Packers are provided at the top and bottom of each oil layer. The packers are located between the oil layer and the casing. The packers are fixedly connected to the oil pipe 15. One end of the adjusting screen is connected to the packer, and the other end is connected to the oil pipe 15. The oil production valve is fixedly connected to the oil pipe 15. A threaded plug 11 is installed at one end of the oil pipe 15.

[0026] The packers include a packer 1, a packer 2, a packer 3, and a packer 4, all of which have the same structure. The oil layer includes an oil layer 12, an oil layer 2, and an oil layer 3, all of which have the same structure.

[0027] The regulating screen tube comprises an outer screen tube 5-2 and an inner screen tube 5-3, between which a memory alloy screen tube 5-4 and an elastic filler 5-5 are arranged, and both ends of the outer screen tube 5-2 and the inner screen tube 5-3 are connected with an upper joint 5-1 and a lower joint 5-6 respectively.

[0028] The oil production valve includes a body 8-1, one end of the body 8-1 is provided with an internal thread, the other end is provided with an external thread, the body 8-1 is connected with an oil inlet channel 1 8-5 and an oil inlet channel 2 8-4, one end of the oil inlet channel 1 8-5 is provided with a valve ball 8-3, and the other end is provided with a thread plug 2 8-2.

[0029] The regulating screen includes regulating screen one 5, regulating screen two 6, and regulating screen three 7 of the same structure. The hole size of the elastic filler 5-5 is set according to the development of the reservoir so that it has a corresponding permeability. According to the proportion of the amount of steam to be injected in each steam injection unit, the steam permeability of the elastic filler 5-5 in each regulating screen is designed, so as to provide different seepage resistances according to different needs, so as to meet the flow requirements of each steam injection unit. Corresponding to each steam injection unit, a regulating screen is connected to the steam injection column, so that the process requirements of simultaneous steam injection and control of the steam injection amount as needed can be met. The lower part of the upper joint 5-1 is turned with internal and external threads and the upper part of the lower joint 5-6 is turned with internal and external threads, and the outer diameter of the outer thread is large and the outer diameter of the inner thread is small. The outer screen 5-2 and the inner screen 5-3 form a rigid mesh container. The elastic filler 5-5 is composed of a mesh permeable material. When the volume increases, the permeability increases. It has no permeability in the initial state. The memory alloy screen tube 5-4 is a rolled structure. It is in a tight state at low temperature, that is, the memory alloy screen tube 5-4 presses the elastic filler 5-5 on the outer circumference of the inner screen tube 5-3. At this time, the adjustment screen tube is in a closed state. In the steam injection state, it is in an expanded state, that is, the outer diameter is larger, and its outer wall fits the outer screen tube 5-2. The tight and expanded states of the memory alloy screen tube 5-4 are used to adjust the steam permeability of the elastic filler 5-5.

[0030] The oil production valve includes an oil production valve 1 8, an oil production valve 2 9, and an oil production valve 3 10 of the same structure. The upper part of the body 8-1 is threaded with internal threads, and the lower part is threaded with external threads to facilitate connection with other components. There are a number of oil inlet channels 1 8-5 on its side along the axial direction, and the oil inlet channel 1 8-5 is connected to the inside of the body 8-1 through the oil inlet channel 2 8-4. The valve ball 8-3 is seated inside the oil inlet channel 1 8-5 to achieve unidirectional flow of fluid. The thread plug 2 8-2 is connected to the upper part of the oil inlet channel 1 8-5 through a fixed connection.

[0031] During steam injection, the packer, regulating screen, oil production valve, plug 11, oil layer, and oil pipe 15 are lowered into the wellbore in sequence. The various components are connected together by fixed connections such as threads. The function of plug 11 is to place the steam injection pipe string under a pressure system. After being lowered into the wellbore, the packer is sealed (mechanical, hydraulic or thermal sealing methods are adopted as needed), and steam is injected from above. Due to the one-way effect of the oil production valve, during steam injection, steam will not enter the oil reservoir through the oil production valve, so that the regulating screen can work alone, and the oil production valve and the regulating screen do not interfere with each other. Due to the function of the regulating screen, each oil reservoir can obtain a more ideal amount of steam according to the design needs, so that the oil reservoir is effectively developed and the single well production capacity is greatly improved.

[0032] After the steam injection volume reaches the designed volume, stop injecting steam into the wellbore, and wait until the wellhead pressure reaches the blowout pressure, and then blow out. After the blowout stops, the temperature in the wellbore returns to the initial state, and the memory alloy screen 5-4 is in a tight state. At this time, the fluid in the wellbore can only enter the pipe string through the oil production valve. The pumping device is lowered. At this time, due to the closing of the adjustment screen, the entire pipe string is in a pressure system, and the crude oil in the oil layer with high pressure in the oil layer begins to flow into the pipe string, avoiding the occurrence of the high-pressure fluid layer in the oil layer backflowing to the low-pressure fluid layer, and preventing the occurrence of mutual contamination between oil layers, which is beneficial to the development of crude oil. The crude oil passes through the oil inlet channel 1 8-5 to push open the valve ball 8-3, passes through the oil inlet channel 2 8-4, and enters the body 8-1. The crude oil is further pumped to the ground through the pumping device.

[0033] During design, the lengths of the inner sieve 5-3 and the outer sieve 5-2 are designed according to the thickness of the reservoir, and the steam permeability of the elastic filler 5-5 corresponding to each reservoir is designed according to the pore fineness, oil saturation, reservoir permeability, steam injection volume and other characteristics of the reservoir.

[0034] Through the invention, the amount of steam required for the steam injection process can be adjusted by using an adjustable screen tube, thereby achieving controllability of steam operation; it is also possible to diffuse steam radially while diffusing steam longitudinally along the annular space, thereby achieving simultaneous radial and longitudinal diffusion of steam along the device.

[0035] It should be noted that the figure shows three steam injection units, three regulating screens and four packers, but the content of the figure is only an example listed for the detailed description of the invention, and is not intended to limit the content of the invention. The number of steam injection units, regulating screens and packers can be increased or decreased according to the actual operation requirements.

[0036] Through the invention, the requirements of simultaneous steam injection, simultaneous well shut-down and simultaneous blowdown of two or more steam injection units can be met during heavy oil thermal recovery, thereby saving operation time and improving operation efficiency. The above-described specific embodiments further explain the purpose, technical scheme and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. Specific embodiments

[0038] Du 813-40-41 is a steam injection well. The oil well is located in the Tainan area of ​​Xinglong, Du 813. The upper cycle is divided into three layers of ball injection and steam injection for oil production. The total steam injection volume is 2090 tons. In the upper cycle, 2619 tons of liquid were produced, 436 tons of oil were produced, and the production lasted for 137.7 days. This cycle uses this uniform steam injection production string, which is divided into three layers of steam injection production, with a total steam injection volume of 2085 tons. In this cycle, 3539 tons of liquid were produced, 620 tons of oil were produced, and the production lasted for 137.7 days. The production capacity of the oil well using this string has been significantly improved.

[0039] The reason is that the steam injection distribution is more scientific and reasonable, which reduces the operation time and further reduces the heat loss in the wellbore; the use of oil production valves reduces the mutual interference between oil production units, making the steam in the high-pressure oil reservoir be reasonably utilized.

[0040] The above-described embodiments are only preferred embodiments of the present invention, and are not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be deemed to be included in the scope of protection of the claims of the present invention. Although the present invention has been described above with reference to the embodiments, various improvements may be made thereto and components thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, as long as there is no technical conflict, the various features in the embodiments disclosed in the present invention may be used in combination with each other in any manner, and the fact that these combinations are not exhaustively described in this specification is only for the sake of omitting space and saving resources. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A uniform steam injection oil production string, characterized in that: The invention comprises an oil pipe (15), a packer is provided at the top and the bottom of each oil layer, the packer is located between the oil layer and the casing, the packer is fixedly connected to the oil pipe (15), one end of the adjusting screen pipe is connected to the packer, and the other end is connected to the oil pipe (15), the oil production valve is fixedly connected to the oil pipe (15), and a threaded plug (11) is installed at one end of the oil pipe (15).

2. The uniform steam injection oil production string according to claim 1, characterized in that: The regulating screen tube comprises an outer screen tube (5-2) and an inner screen tube (5-3); a memory alloy screen tube (5-4) and an elastic filler (5-5) are arranged between the outer screen tube (5-2) and the inner screen tube (5-3); and an upper joint (5-1) and a lower joint (5-6) are respectively connected at both ends of the outer screen tube (5-2) and the inner screen tube (5-3).

3. The uniform steam injection oil production string according to claim 1, characterized in that: The oil production valve comprises a body (8-1), one end of the body (8-1) is provided with an internal thread, and the other end is provided with an external thread, the body (8-1) is connected with an oil inlet channel 1 (8-5) and an oil inlet channel 2 (8-4), one end of the oil inlet channel 1 (8-5) is provided with a valve ball (8-3), and the other end is provided with a thread plug 2 (8-2).

4. The uniform steam injection oil production string according to claim 2, characterized in that: The lower part of the upper joint (5-1) is machined with internal and external threads, and the upper part of the lower joint (5-6) is machined with internal and external threads, wherein the external thread has a larger outer diameter and the internal thread has a smaller outer diameter.

5. The uniform steam injection oil production string according to claim 2, characterized in that: The outer sieve tube (5-2) and the inner sieve tube (5-3) form a rigid mesh container.

6. The uniform steam injection oil production string according to claim 2, characterized in that: The elastic filler (5-5) is a mesh-shaped air-permeable material.

7. The uniform steam injection oil production string according to claim 2, characterized in that: The memory alloy screen tube (5-4) is a rolled structure, which is in a tightly-packed state under low temperature conditions and in an unfolded state under steam injection conditions.

8. The uniform steam injection oil production string according to claim 2, characterized in that: The outer wall of the memory alloy screen tube (5-4) is fitted to the outer screen tube (5-2).

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