Balanced steam injection device for multi-medium composite thermal recovery horizontal well

Abstract

The invention discloses a balanced steam injection device for a multi-medium composite thermal recovery horizontal well. The balanced steam injection device comprises a heat insulation oil pipe, a vertical sleeve, a thermosensitive packer, a steam injection pipe column unit, an injection allocation device, a horizontal oil pipe and a horizontal screen pipe. The heat insulation oil pipe is arranged in the vertical sleeve and is connected with the horizontal oil pipe; the thermosensitive packer is arranged at the joint of the heat insulation oil pipe and the horizontal oil pipe; the vertical sleeve is connected with the horizontal screen pipe; the horizontal oil pipe is arranged in the horizontal screen pipe; the steam injection pipe column unit is arranged in the heat insulation oil pipe and the horizontal oil pipe; the multiple injection allocation devices are arranged on the steam injection tubular column unit. Multi-pipe steam injection is adopted, and the proportion of all components of the composite media of different well sections of the horizontal well can be adjusted; according to the horizontal section packer, the injection allocation device is divided to correspond to all well sections of the horizontal well, the size of the injection allocation valve is adjusted according to the oil layer physical properties of the different well sections of the horizontal well, the composite thermal medium is balanced, the heat injection efficiency is improved, and the thermal recovery effect is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil production equipment, and in particular relates to a multi-media composite thermal production horizontal well balanced steam injection device. Background Art

[0002] The existing multi-media composite thermal recovery technology mainly injects fuel, air, and water into the high-pressure combustion chamber of the generator to generate a mixture composed of CO2, N2, water vapor, etc., and then injects the composite medium into the wellbore of the thermal recovery well. The steam and non-condensable gas components in the composite medium carry heat and diffuse in the oil layer, forming a gas cavity and heating volume under the synergistic effect of gas and heat. The main production increase mechanisms of conventional steam flooding for heavy oil production include crude oil heating viscosity reduction, thermal expansion, steam distillation, and improvement of oil phase permeability. In addition to the above-mentioned oil increase mechanisms, multi-media composite thermal recovery technology also includes the following three aspects: (1) Composite viscosity reduction. High-temperature and high-pressure steam carries a large amount of latent heat, which can increase the temperature of the oil layer and change the physical properties of the formation crude oil. At the same time, carbon dioxide dissolves in the crude oil, which can effectively reduce the viscosity of the crude oil and increase the fluidity of the crude oil, thereby improving the flow properties of the crude oil and playing a role of composite viscosity reduction; (2) dissolution and expansion effect. When carbon dioxide dissolves in heavy oil, it expands the volume of the heavy oil, which not only increases the internal kinetic energy of the crude oil, but also significantly reduces the capillary resistance and flow resistance during the flow of the crude oil, thereby improving the flow capacity of the crude oil. (3) Pressure maintenance and energy enhancement effect. The mixed injection of hot steam and nitrogen fully utilizes the large elastic energy of nitrogen during oil displacement, which can compensate for the pressure reduced by steam condensation, thereby maintaining the formation pressure.

[0003] Existing techniques typically inject the composite medium produced by the generator directly into the thermal recovery wellbore, making it impossible to control the proportions of the composite medium components in different sections of the horizontal well. During steam injection, the composite medium injected downhole flows back into the insulation zone within the vertical casing. If the formation is heterogeneous and thick, some areas have strong steam absorption capacity while others have weaker capacity, resulting in uneven steam injection and seriously affecting thermal recovery effectiveness.

[0004] Existing technologies are unable to adjust the ratio of injected multi-media composites based on the physical properties of different reservoirs in different sections of horizontal wells. Consequently, existing technologies cannot effectively address the problem of poor recovery results in heavy oil thermal recovery wells due to uneven utilization of horizontal sections. Summary of the Invention

[0005] In order to solve the above problems, the present invention discloses a multi-media composite thermal recovery horizontal well balanced steam injection device, comprising: an insulated oil pipe, a vertical casing, a thermal packer, a steam injection string unit, an injector, a horizontal oil pipe and a horizontal screen pipe;

[0006] The heat-insulating oil pipe is arranged in the vertical casing and connected to the horizontal oil pipe;

[0007] The thermal packer is arranged at the connection between the thermal insulation oil pipe and the horizontal oil pipe;

[0008] The vertical casing is connected to the horizontal screen pipe;

[0009] The horizontal oil pipe is arranged in the horizontal screen pipe;

[0010] The steam injection string unit is arranged in the heat-insulating oil pipe and the horizontal oil pipe;

[0011] A plurality of injectors are arranged on the steam injection column unit.

[0012] Furthermore, it also includes: a reducing pipe;

[0013] The heat-insulating oil pipe is connected to the horizontal oil pipe via a reducing pipe.

[0014] Furthermore, the steam injection string unit includes a first steam injection string, a second steam injection string and a third steam injection string;

[0015] The first steam injection string, the second steam injection string and the third steam injection string are arranged in the heat-insulating oil pipe and the horizontal oil pipe;

[0016] A plurality of injectors are arranged at intervals on the first steam injection pipe string, the second steam injection pipe string and the third steam injection pipe string.

[0017] Furthermore, it also includes: a centralizer;

[0018] A plurality of centralizers are arranged between the horizontal oil pipe and the horizontal screen pipe.

[0019] Further, it also includes: a packer;

[0020] The packer is arranged between the injectors;

[0021] The packer is provided with a sealing ring, and the steam injection string unit passes through the sealing ring.

[0022] Furthermore, it also includes: an injection valve;

[0023] A plurality of dispensing valves are evenly distributed on the outer circumference of the dispensing device;

[0024] The sizes of the injection valves on each of the injectors are the same.

[0025] Furthermore, it also includes: a guide cone;

[0026] The guide cone is conical and is arranged at the end of the horizontal oil pipe.

[0027] Furthermore, the horizontal screen tube is provided with air holes;

[0028] The size of the air hole is not less than the size of the injection valve.

[0029] Furthermore, the valve opening adjustment of the injection valve is set according to the corresponding oil layer physical properties.

[0030] Furthermore, there are no less than three dispensers.

[0031] Compared with the prior art, the embodiments of the present invention have at least the following advantages:

[0032] 1. The present invention adopts multi-tube steam injection to adjust the proportion of each component of the composite medium in different sections of the horizontal well;

[0033] 2. The thermal packer of the present invention can effectively block the backflow of the multi-media composite into the casing annulus of the vertical well section, effectively improving the service life of the insulated oil pipe;

[0034] 3. The horizontal section packer in the present invention divides the injection valve into sections corresponding to the horizontal well sections. The injection valve size is adjusted according to the reservoir physical properties of different sections of the horizontal well, so that the composite heat medium acts in a balanced manner, the heat injection efficiency is improved, and the thermal recovery effect is further enhanced.

[0035] 4. The present invention is provided with a centralizer, which can stably fix the steam injection pipe string in the horizontal screen pipe, ensuring construction safety, effectively preventing the steam injection pipe string from being stuck, and maximizing the utilization of hot steam.

[0036] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. 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 any creative work.

[0038] Figure 1 A structural schematic diagram of a multi-media composite thermal recovery horizontal well balanced steam injection device according to an embodiment of the present invention is shown.

[0039] Figure numerals: 1. Insulated oil pipe; 2. Vertical casing; 3. Thermal-sensitive packer; 4. Reducer; 5. First steam injection string; 6. Second steam injection string; 7. Third steam injection string; 8. Injection device; 9. Centralizer; 10. Packer; 11. Horizontal oil pipe; 12. Injection valve; 13. Horizontal screen pipe; 14. Guide cone. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0041] Figure 1 The following is a schematic diagram showing the structure of a multi-media composite thermal recovery horizontal well balanced steam injection device according to an embodiment of the present invention. Figure 1 As shown, the present invention proposes a multi-media composite thermal recovery horizontal well balanced steam injection device, comprising: a vertically arranged insulated oil pipe 1, a vertical casing 2, a thermal packer 3, a steam injection string unit, an injector 8, a horizontal oil pipe 11 horizontally extending into the oil layer, and a horizontal screen 13;

[0042] The heat-insulated oil pipe 1 is arranged in the vertical casing 2, the upper part of the heat-insulated oil pipe 1 is connected to the steam injection wellhead, and the lower part is connected to the horizontal oil pipe 11;

[0043] The thermal packer 3 is arranged at the connection between the thermal insulation oil pipe 1 and the horizontal oil pipe 11;

[0044] The vertical casing 2 is connected to the horizontal screen pipe 13;

[0045] The horizontal oil pipe 11 is arranged in the horizontal screen pipe 13;

[0046] The steam injection string unit is arranged in the heat-insulating oil pipe 1 and the horizontal oil pipe 11;

[0047] A plurality of the injectors 8 are arranged on the steam injection column unit.

[0048] In some embodiments, the connection between the vertical casing 2 and the horizontal screen pipe 13 is an arc-shaped elbow.

[0049] The insulated oil pipe 1 is used to reduce the heat loss of the injected medium and increase the injection depth; reduce the thermal stress of the vertical casing 2 and the cement sheath, and prevent the vertical casing 2 from being damaged by high temperature;

[0050] The vertical casing 2 is used to strengthen the well wall and prevent the occurrence of well wall collapse and wellhead collapse accidents. It can also ensure the safety and smooth progress of underground operations and protect the pipeline inside the vertical casing 2;

[0051] Thermal packer 3, used to block the backflow of multi-media composite into the casing annulus of the vertical well section, which can effectively reduce the heat loss of steam along the wellbore and improve the thermal recovery effect;

[0052] Steam injection column unit, used to inject high-temperature and high-pressure N2, CO2 and water vapor;

[0053] The injection device 8 is used to adjust the size of the injection valve 12 according to the physical properties of the oil layers in different sections of the horizontal well, so as to achieve a balanced effect of the composite heat medium on the target oil layer;

[0054] The horizontal oil pipe 11 is used to protect the internal pipeline and reduce the heat loss of the injected medium. It is also provided with a vent hole.

[0055] The horizontal screen pipe 13 is used to pass the composite heat medium so that it acts on the target oil layer; it can also be used for sand control.

[0056] The heat-sensitive packer 3 in the present invention can effectively block the multi-media composite from flowing back into the casing annulus of the vertical well section, thereby effectively increasing the service life of the insulated oil pipe 1.

[0057] In some embodiments, the multi-media composite thermal recovery horizontal well balanced steam injection device further includes: a reducing pipe 4;

[0058] The heat-insulating oil pipe 1 and the horizontal oil pipe 11 are fastened together via a reducing pipe 4 .

[0059] In some embodiments, the steam injection string unit includes a first steam injection string 5, a second steam injection string 6 and a third steam injection string 7;

[0060] The first steam injection string 5, the second steam injection string 6 and the third steam injection string 7 are installed in the insulated oil pipe 1 and the horizontal oil pipe 11;

[0061] A plurality of dispensers 8 are spaced apart and arranged on the first steam injection pipe string 5 , the second steam injection pipe string 6 and the third steam injection pipe string 7 which are located in a horizontal position.

[0062] The first steam injection column 5 is used to inject high-temperature and high-pressure CO2;

[0063] The second steam injection string 6 is used to inject high-temperature and high-pressure steam;

[0064] The third steam injection column 7 is used for high-temperature and high-pressure N2.

[0065] The present invention adopts multi-tube steam injection to adjust the proportions of various components of the composite medium in different sections of the horizontal well.

[0066] In some embodiments, the multi-media composite thermal recovery horizontal well balanced steam injection device further includes: a centralizer 9;

[0067] A plurality of centralizers 9 are provided between the horizontal oil pipe 11 and the horizontal screen pipe 13 .

[0068] The radial arrangement of the centralizer 9 can ensure that the horizontal oil pipe 11 is stably centered in the horizontal screen pipe 13, effectively preventing the steam injection pipe string from being stuck, maximizing the utilization of hot steam, and achieving high thermal energy utilization rate.

[0069] In some embodiments, the multi-media composite thermal recovery horizontal well balanced steam injection device further includes: a packer 10;

[0070] The packer 10 is arranged between the injectors 8;

[0071] The packer 10 is provided with a sealing ring, through which the steam injection string unit passes. The packer 10 is provided to seal around the first steam injection string 5, the second steam injection string 6 and the third steam injection string 7.

[0072] The packer 10 is used to separate the injectors 8 on the steam injection string and corresponds to each section of the horizontal well.

[0073] In some embodiments, the multi-media composite thermal recovery horizontal well balanced steam injection device further includes: an injection valve 12;

[0074] A plurality of dispensing valves 12 are evenly distributed on the outer circumference of the dispensing device 8;

[0075] The sizes of the injection valves 12 on each of the injectors 8 are the same.

[0076] Exemplarily, no less than three dispensing valves 12 are evenly distributed on the outer circumference of the dispenser 8 .

[0077] The injection valve 12 is used to adjust and control the flow rate and pressure of the injected medium.

[0078] The size of the injection valve 12 is adjusted according to the physical properties of the oil layers in different sections of the horizontal well to achieve a balanced effect of the composite heat medium, thereby improving the heat injection efficiency and further enhancing the thermal recovery effect.

[0079] In some embodiments, the multi-media composite thermal recovery horizontal well balanced steam injection device further includes: a guide cone 14;

[0080] The guide cone 14 is conical and is arranged at the end of the horizontal oil pipe 11 .

[0081] The guide cone 14 is used to guide the injection and production process string of the heavy oil thermal recovery horizontal well.

[0082] In some embodiments, in a multi-media composite thermal recovery horizontal well balanced steam injection device, the horizontal screen pipe 13 is provided with air holes;

[0083] The size of the air hole is not less than the size of the injection valve 12.

[0084] In some embodiments, in a multi-media composite thermal recovery horizontal well balanced steam injection device, the valve opening size of the injection valve 12 is adjusted according to the corresponding oil layer physical properties.

[0085] In some embodiments, the multi-media composite thermal recovery horizontal well balanced steam injection device has no less than three injectors 8.

[0086] The valve opening size of the injection valve 12 provided on the injector 8 is adjusted according to the corresponding oil layer physical properties. The injection valves 12 are evenly distributed on the periphery of the injector 8, and the valve sizes of the injection valves 12 on each injector 8 are the same.

[0087] A certain amount of CO2, N2, and water vapor are injected through the first steam injection string 5, the second steam injection string 6, and the third steam injection string 7, respectively. The size of the injection valve 12 is adjusted according to the physical properties of the oil layer in different sections of the horizontal well, and the injection amount of CO2, N2, and water vapor in different sections of the horizontal well is controlled, thereby adjusting the proportion of each component of the composite medium in different sections of the horizontal well, making the composite heat medium act in a balanced manner, improving the heat injection efficiency, and further enhancing the thermal recovery effect. The thermal-sensitive packer 3 in the vertical casing 2 can effectively block the composite medium in the horizontal well section from flowing back into the casing annulus of the vertical well section. The packer 10 divides the injector 8 evenly in different sections of the horizontal well, and sets the injection valve 12 of corresponding size according to the physical properties of different oil layers to achieve balanced steam injection.

[0088] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying 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 element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0089] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0090] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0091] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0092] In the description of the present invention, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In the present invention, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine different embodiments or examples described in the present invention and features of different embodiments or examples without contradiction.

[0093] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-media composite thermal recovery horizontal well balanced steam injection device, characterized in that: include: Insulated oil pipe (1), vertical casing (2), thermal packer (3), steam injection string unit, injection device (8), horizontal oil pipe (11) and horizontal screen pipe (13); The heat-insulating oil pipe (1) is arranged in the vertical casing (2) and connected to the horizontal oil pipe (11); The heat-sensitive packer (3) is arranged at the connection between the heat-insulated oil pipe (1) and the horizontal oil pipe (11); The vertical casing (2) is connected to the horizontal screen pipe (13); The horizontal oil pipe (11) is arranged in a horizontal screen pipe (13); The steam injection column unit is arranged in the heat-insulating oil pipe (1) and the horizontal oil pipe (11); A plurality of the injectors (8) are arranged on the steam injection column unit.

2. The multi-media composite thermal recovery horizontal well balanced steam injection device according to claim 1, characterized in that: Also includes: Reducer (4); The heat-insulating oil pipe (1) is connected to the horizontal oil pipe (11) via a reducing pipe (4).

3. The multi-media composite thermal recovery horizontal well balanced steam injection device according to claim 1, characterized in that: The steam injection pipe column unit comprises a first steam injection pipe column (5), a second steam injection pipe column (6) and a third steam injection pipe column (7); The first steam injection pipe string (5), the second steam injection pipe string (6) and the third steam injection pipe string (7) are arranged in the heat-insulating oil pipe (1) and the horizontal oil pipe (11); A plurality of injectors (8) are arranged at intervals on the first steam injection pipe column (5), the second steam injection pipe column (6) and the third steam injection pipe column (7).

4. The multi-media composite thermal recovery horizontal well balanced steam injection device according to claim 1, characterized in that: Also includes: Centralizer (9); A plurality of centralizers (9) are provided between the horizontal oil pipe (11) and the horizontal screen pipe (13).

5. The multi-media composite thermal recovery horizontal well balanced steam injection device according to claim 1, characterized in that: Also includes: Packer (10); The packer (10) is arranged between the dispensers (8); The packer (10) is provided with a sealing ring, and the steam injection string unit passes through the sealing ring.

6. The multi-media composite thermal recovery horizontal well balanced steam injection device according to claim 1, characterized in that: Also includes: Injection valve (12); A plurality of dispensing valves (12) are evenly distributed on the outer circumference of the dispensing device (8); The sizes of the injection valves (12) on each of the injectors (8) are the same.

7. The multi-media composite thermal recovery horizontal well balanced steam injection device according to claim 1, characterized in that: Also includes: Guide cone (14); The guide cone (14) is tapered and is arranged at the end of the horizontal oil pipe (11).

8. The multi-media composite thermal recovery horizontal well balanced steam injection device according to claim 6, characterized in that: The horizontal screen tube (13) is provided with air holes; The size of the air hole is not less than the size of the injection valve (12).

9. The multi-media composite thermal recovery horizontal well balanced steam injection device according to claim 6 or 8, characterized in that: The valve opening adjustment of the injection valve (12) is set according to the corresponding oil layer physical properties.

10. The multi-media composite thermal recovery horizontal well balanced steam injection device according to claim 1, characterized in that: There are no less than three dispensers (8).

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