A method and a regulation system for deep geothermal energy and shallow heavy oil reservoir collaborative three-dimensional development

Abstract

The application discloses a method and a regulation system for deep geothermal energy and shallow heavy oil reservoir collaborative three-dimensional development, which aims at efficiently solving the problem of high viscosity of crude oil in the development process of the shallow heavy oil reservoir. Specifically, the application ingeniously utilizes the rich geothermal energy resources in the deep stratum, extracts the heat energy of the deep geothermal water through advanced mining technology, and directly applies the heat energy to the mining process of the shallow heavy oil reservoir, so that the viscosity of the heavy oil can be effectively reduced, the flowability of the crude oil is improved, a low-cost hot water displacement technology is realized, and the energy consumption and cost in the traditional heavy oil mining are greatly reduced. The application not only provides a new idea and technical means for efficient development of the shallow heavy oil reservoir, but also opens up a new application field for reasonable utilization of the deep geothermal energy, realizes the complementary advantages and three-dimensional development of the geothermal energy and the petroleum resources, and has important significance for promoting the optimization and upgrading of the energy structure in China and even the whole world.

Description

Technical Field

[0001] This invention belongs to the fields of heavy oil reservoir development technology and geothermal energy evaluation and development technology. It is a method and control system for the coordinated three-dimensional development of deep geothermal energy and shallow heavy oil reservoirs. Background Technology

[0002] Heavy oil reservoirs are characterized by high crude oil viscosity and poor fluidity, which significantly increases the difficulty of extraction. Heating to reduce viscosity is currently the most mature and effective method for developing heavy oil reservoirs. Traditional heating methods encompass various technologies, such as hot water flooding, steam huff and puff, steam-assisted gravity drainage (SAGD), and steam drive. In shallow heavy oil reservoirs, the crude oil viscosity is generally in the range of 200–300 mPa·s, mainly due to the low formation temperature leading to poor crude oil fluidity. Hot water flooding can significantly improve the fluidity of the crude oil, achieving better viscosity reduction and development results.

[0003] However, traditional methods of hot water production mostly rely on coal-fired or gas-fired boilers. These methods not only consume enormous amounts of energy but also generate high carbon emissions, resulting in high heating costs and significant environmental pressure. Given this situation, geothermal energy, as a clean and renewable energy source, has advantages such as large reserves, wide distribution, green and low-carbon characteristics, and low cost. Therefore, extracting deep geothermal water from shallow heavy oil blocks and injecting it into heavy oil reservoirs to increase reservoir temperature and crude oil fluidity can effectively reduce the cost of heating and reducing the viscosity of heavy oil. This approach not only effectively reduces the cost of heating and reducing the viscosity of heavy oil but also enables low-cost hot water drive development in shallow heavy oil reservoirs, ultimately achieving synergistic and integrated development of deep geothermal energy and shallow heavy oil reservoirs, realizing the dual goals of efficient resource utilization and environmental protection.

[0004] CN 111608624 discloses a method for exploiting heavy oil reservoirs using geothermal energy, comprising the following steps: Step 1, determining whether there are any usable geothermal layers above or below the target oil reservoir based on the geological conditions of the area; Step 2, after discovering usable geothermal resources, deploying at least two injection wells and at least one production well in the target oil reservoir area, wherein the injection wells are used for injecting injection fluid; Step 3, using the geothermal resources of the geothermal layer to heat the injection fluid, and the heated injection fluid displaces the crude oil in the heavy oil reservoir, thereby realizing the exploitation of the heavy oil reservoir. However, this patent is limited to elucidating the basic theoretical framework for developing heavy oil reservoirs using geothermal resources, and has not yet explored in depth the specific geothermal exploitation techniques, the separation and treatment process of produced water, and the key technical details necessary for field implementation, such as the actual application strategies in heavy oil injection operations. Therefore, its research scope is still limited to the theoretical discussion level and has not yet entered the exploration stage of practical application. Summary of the Invention

[0005] To address the issues of high energy consumption, high cost, and high carbon emissions during the hydrothermal flooding development of shallow heavy oil reservoirs, this invention proposes a method and control system for the coordinated three-dimensional development of deep geothermal energy and shallow heavy oil reservoirs, taking advantage of the wide distribution and low cost of geothermal energy.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for the coordinated and integrated development of deep geothermal energy and shallow heavy oil reservoirs includes the following steps:

[0008] S1. Geothermal water extraction: Hot water from the geothermal reservoir enters the geothermal water extraction well, and after being pressurized by the water extraction pump, it is transported upward along the oil pipe of the water extraction well to the water extraction wellhead.

[0009] S2. Heavy oil water injection: After the geothermal water flows out of the wellhead, it reaches the injection wellhead through the automatic water distribution system, and is injected into the shallow heavy oil layer through the injection well tubing and the heavy oil water injection well.

[0010] S3. Heavy oil production: Geothermal water heats the oil layer and displaces crude oil to the heavy oil production well. The oil-water mixture is then pumped to the production well tubing and continues to be transported to the wellhead.

[0011] S4. Oil-water separation: After the oil-water mixture flows out of the wellhead, it is separated by an oil-water separation device.

[0012] S5. Geothermal reinjection: The separated water is injected into the geothermal reinjection well through the reinjection wellhead and the reinjection well tubing, returning to the geothermal reservoir.

[0013] S6. Each geothermal water production well can simultaneously provide hot water to multiple heavy oil injection wells, and the water volume can be automatically divided and regulated through an automatic water distribution system. By injecting hot water into the injection wells, the viscosity of the heavy oil in the reservoir pores is reduced, and the reduced crude oil is displaced and moved towards the production wells.

[0014] Furthermore, the automatic water distribution system of the present invention consists of a flow stabilizer and a flow meter connected together.

[0015] This invention also seeks protection for a three-dimensional development and control system for deep geothermal energy and shallow heavy oil reservoirs, which includes setting up geothermal water production wells and geothermal reinjection wells in the geothermal reservoir; the geothermal water production wells are equipped with water production pumps and water production well tubing; and the geothermal reinjection wells are equipped with reinjection well tubing.

[0016] Heavy oil injection wells and heavy oil production wells are installed in shallow heavy oil layers; water injection wells are equipped with water injection tubing; and production wells are equipped with production pumps and production tubing.

[0017] Furthermore, an automatic water separation system is installed on the oil pipe connecting the geothermal water production well and the heavy oil injection well. An oil-water separation device is installed on the oil pipe connecting the geothermal reinjection well and the heavy oil production well.

[0018] Furthermore, the geothermal water extraction well is connected to several heavy oil injection wells.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention innovatively proposes a method and control system for the synergistic three-dimensional development of deep geothermal energy and shallow heavy oil reservoirs. This method aims to efficiently and economically solve the problem of high crude oil viscosity faced during the development of shallow heavy oil reservoirs. Specifically, this invention cleverly utilizes the abundant geothermal energy resources deep within the formation. Through advanced extraction technology, the thermal energy of deep geothermal water is extracted and directly applied to the extraction process of shallow heavy oil reservoirs. In this process, the injection of deep geothermal water not only effectively reduces the viscosity of heavy oil, thereby improving its fluidity, but also achieves low-cost hot water displacement technology, significantly reducing energy consumption and costs in traditional heavy oil extraction.

[0021] On the other hand, this invention designs a highly intelligent automatic water distribution system that can monitor and precisely control the amount of geothermal water injected into the injection wells in real time. This control mechanism ensures that the amount of geothermal water injected into shallow heavy oil reservoirs meets the viscosity reduction requirements while avoiding problems such as abnormal reservoir pressure or water waste caused by excessive injection. Through this refined control method, this invention not only achieves efficient synergistic development of deep geothermal energy and shallow heavy oil resources, but also ensures environmental friendliness and sustainability during the development process.

[0022] In summary, this invention not only provides a novel approach and technical means for the efficient development of shallow heavy oil reservoirs, but also opens up new application areas for the rational utilization of deep geothermal energy, realizing the complementary advantages and three-dimensional development of geothermal energy and petroleum resources. This is of great significance for promoting the optimization and upgrading of my country's and even the world's energy structure. Attached Figure Description

[0023] Figure 1 A flowchart illustrating a method for the coordinated and three-dimensional development of deep geothermal energy and shallow heavy oil reservoirs;

[0024] Figure 2 This is a schematic diagram of an automatic water distribution system.

[0025] In the diagram, 1. Geothermal reservoir; 2. Geothermal water production well; 3. Water production pump; 4. Water production well tubing; 5. Water production wellhead; 6. Automatic water distribution system; 7. Water injection wellhead; 8. Water injection well tubing; 9. Heavy oil water injection well; 10. Shallow heavy oil layer; 11. Heavy oil production well; 12. Oil production pump; 13. Oil production well tubing; 14. Oil production wellhead; 15. Oil-water separation device; 16. Reinjection wellhead; 17. Reinjection well tubing; 18. Geothermal reinjection well. Detailed Implementation

[0026] To more clearly illustrate the purpose, technical solutions, and advantages of this disclosure, the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the following description of the embodiments is intended to explain and illustrate the overall concept of this disclosure and should not be construed as limiting the disclosure. In the specification and drawings, the same or similar reference numerals refer to the same or similar parts or components. For clarity, the drawings are not necessarily drawn to scale, and some well-known parts and structures may be omitted from the drawings.

[0027] In the description of this disclosure, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] Furthermore, the technical features involved in the different embodiments of this disclosure described below can be combined with each other as long as they do not conflict with each other.

[0030] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The word “a” or “an” does not exclude multiple components. Terms such as “including” or “comprising” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” “right,” “top,” or “bottom,” etc., are used only to indicate relative positional relationships, which may change accordingly when the absolute position of the described object changes. When an element such as a layer, film, region, or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element, or there may be intermediate elements present.

[0031] The method for the coordinated three-dimensional development of deep geothermal energy and shallow heavy oil reservoirs in this embodiment includes the following steps:

[0032] Geothermal water extraction: Hot water from the geothermal reservoir enters the geothermal water extraction well and is transported to the wellhead;

[0033] Heavy oil water injection: After the geothermal water flows out of the wellhead, it is injected into the shallow heavy oil layer through the automatic water distribution system.

[0034] Heavy oil production: Geothermal water is used to heat the oil layer and displace crude oil to the heavy oil production well, and the oil-water mixture is extracted and transported to the wellhead;

[0035] Oil-water separation: The oil-water mixture is separated by an oil-water separation device;

[0036] Geothermal reinjection: The separated water is returned to the geothermal reservoir.

[0037] Example 1

[0038] Geothermal water production well 2 and geothermal reinjection well 18 are installed in geothermal reservoir 1; water production pump 3 and water production well tubing 4 are installed in geothermal water production well 2; reinjection well tubing 17 is installed in geothermal reinjection well 18.

[0039] A heavy oil water injection well 9 and a heavy oil production well 11 are provided in the shallow heavy oil layer 10; a water injection well tubing 8 is provided in the heavy oil water injection well 9; an oil production pump 12 and an oil production well tubing 13 are provided in the heavy oil production well 11.

[0040] The geothermal water extraction well 2 and the heavy oil injection well 9 are connected by an oil pipe, and an automatic water distribution system 6 is installed on the oil pipe;

[0041] The geothermal reinjection well 18 is connected to the heavy oil production well 11 by an oil pipe, and an oil-water separator 15 is installed on the oil pipe.

[0042] Example 2

[0043] Combined with appendix Figure 2 The automatic water distribution system consists of a steady-flow water distributor and a flow meter controller. The steady-flow water distributor can be set individually for the injection volume q of each heavy oil injection well. It automatically adjusts the opening of the nozzle on the steady-flow water distributor according to the injection volume to complete the injection task. The flow meter controller can monitor the flow rate of the water injection pipeline of each well in real time. When it detects that the injection volume deviates from the injection value, it sends a command to the steady-flow water distributor to adjust the nozzle opening to the preset injection volume in a timely manner, so as to accurately complete the injection volume of each injection well.

[0044] The rated injection capacity of this well is 240 cubic meters per day, which translates to a flow rate of 10 cubic meters per hour. However, the current flow rate displayed by the flow meter is 20 cubic meters per hour, exceeding the injection capacity. Therefore, the flow meter triggers a command to the nozzle adjustment mechanism of the flow stabilizer, reducing its opening to precisely regulate the flow rate to the preset 10 cubic meters per hour, thus achieving stable flow control.

[0045] Example 3

[0046] A method for the coordinated and integrated development of deep geothermal energy and shallow heavy oil reservoirs includes the following steps:

[0047] S1. Geothermal water extraction: Hot water in the geothermal reservoir 1 enters the geothermal water extraction well 2, and after being pressurized by the water extraction pump 3, it is transported upward along the water extraction well oil pipe 4 to the water extraction wellhead 5.

[0048] S2. Heavy oil water injection: After the geothermal water flows out of the wellhead, it reaches the injection wellhead 7 through the automatic water distribution system 6, and is injected into the shallow heavy oil layer 10 through the injection well tubing 8 and the heavy oil water injection well 9.

[0049] S3. Heavy oil production: Geothermal water heats the oil layer and displaces crude oil to the heavy oil production well 11. The oil-water mixture is pumped to the production well tubing 13 by the production pump 12 and then transported to the production wellhead 14.

[0050] S4. Oil-water separation: After the oil-water mixture flows out of the wellhead 14, it is separated by the oil-water separation device 15.

[0051] S5. Geothermal reinjection: The separated water is injected into the geothermal reinjection well 18 through the reinjection wellhead 16 and the reinjection well tubing 17, and then returns to the geothermal reservoir 1.

[0052] S6. Geothermal water well 2 can provide hot water to multiple heavy oil injection wells and automatically control the water volume through an automatic water distribution system.

[0053] Example 4

[0054] Synergistic three-dimensional development of deep geothermal energy and heavy oil reservoirs is being carried out in a shallow heavy oil block in my country.

[0055] (1) Geothermal water production: Geothermal hot water from geothermal reservoir 1 flows into geothermal water production well 2, and is pumped to the well tubing 4 by water pump 3, and then transported upwards to the wellhead 5. The daily production of this well is 1100 m³. 3 / d, outlet water temperature 72℃.

[0056] (2) Heavy oil water injection: After the geothermal water flows out of the production wellhead 5, it reaches the injection wellhead 7 through the automatic water distribution system 6. After passing through the injection wellhead, it is injected into the heavy oil water injection well 9 through the injection well tubing 8, and then injected into the shallow heavy oil layer 10. There are 4 heavy oil water injection wells in this block, with a daily injection volume of 200 m³ / h. 3 / d、250m 3 / d、300m 3 / d、350m 3 / d.

[0057] (3) Heavy oil production: Through the heating and displacement effect of geothermal water, the flowing heavy oil is transported into the wellbore of the heavy oil production well 11. The oil-water mixture is pumped into the oil tubing 13 of the production well by the oil production pump 12 and continues to be transported to the wellhead 14.

[0058] (4) Oil-water separation: After the heavy oil flows out of the wellhead 14, the extracted oil-water mixture is separated by the oil-water separation device 15.

[0059] (5) Geothermal reinjection well reinjection: The separated water is injected into the geothermal reinjection well 18 through the reinjection wellhead 16 and the reinjection well tubing 17, and returns to the geothermal reservoir 1.

[0060] (6) This block utilizes one geothermal water production well 2 to provide hot water to four heavy oil injection wells (e.g., Figure 2 The daily injection volume of the injection wells is 200m³. 3 / d、250m 3 / d、300m 3 / d、350m 3 / d, the automatic water distribution system 6 is used to automatically divide the daily water injection volume. The water injection volume of 4 injection wells is set by the flow stabilizer, and the water nozzle opening is automatically adjusted to complete the water injection task. When the daily water injection volume deviates from the preset value, it is adjusted in real time by the flow meter.

[0061] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for the coordinated three-dimensional development of deep geothermal energy and shallow heavy oil reservoirs, characterized in that, Includes the following steps: Geothermal water extraction: Hot water in the geothermal reservoir (1) enters the geothermal water extraction well (2) and is transported to the wellhead (5); Heavy oil water injection: After the geothermal water flows out of the wellhead (5), it reaches the wellhead (7) of the injection well through the automatic water distribution system (6) and is injected into the shallow heavy oil layer (10); Heavy oil production: Geothermal water is used to heat the oil layer and displace crude oil to the heavy oil production well (11), and the oil-water mixture is extracted and transported to the wellhead (14); Oil-water separation: The oil-water mixture is separated by an oil-water separation device (15); Geothermal reinjection: The separated water is returned to the geothermal reservoir (1).

2. The method according to claim 1, characterized in that, Specifically, the steps include the following: S1. Geothermal water extraction: Hot water in the geothermal reservoir (1) enters the geothermal water extraction well (2), and after being pressurized by the water extraction pump (3), it is transported upward along the water extraction well oil pipe (4) to the water extraction wellhead (5); S2. Heavy oil water injection: After the geothermal water flows out of the wellhead (5), it reaches the wellhead (7) of the injection well through the automatic water distribution system (6), and is injected into the shallow heavy oil layer (10) through the oil pipe (8) of the injection well and the heavy oil water injection well (9). S3. Heavy oil production: Geothermal water heats the oil layer and displaces crude oil to the heavy oil production well (11). The oil-water mixture is pumped to the production well tubing (13) by the production pump (12) and continues to be transported to the production wellhead (14). S4. Oil-water separation: After the oil-water mixture flows out of the wellhead (14), it is separated into oil and water by an oil-water separation device (15); S5. Geothermal reinjection: The separated water is injected into the geothermal reinjection well (18) through the reinjection wellhead (16) and the reinjection well tubing (17), and returns to the geothermal reservoir (1); S6. Each geothermal water well (2) can simultaneously provide hot water to multiple heavy oil injection wells and achieve automatic water volume splitting and regulation through an automatic water distribution system.

3. The method according to claim 1, characterized in that, The automatic water distribution system (6) consists of a steady flow water distributor and a flow meter and controller connected together.

4. The method according to claim 3, characterized in that, The steady-flow water distributor can be set individually for the injection volume q of each heavy oil injection well. It automatically adjusts the opening of the water nozzle on the steady-flow water distributor according to the injection volume to complete the injection task.

5. The method according to claim 3, characterized in that, The flow meter monitors the flow rate of the water injection pipeline in each well in real time.

6. The method according to claim 3, characterized in that, If the flow meter detects that the water injection volume deviates from the injection value, it will issue an instruction to adjust the nozzle opening in a timely manner to accurately complete the injection volume of each injection well.

7. A three-dimensional development and control system for the coordinated development of deep geothermal energy and shallow heavy oil reservoirs, characterized in that, Geothermal water extraction well (2) and geothermal reinjection well (18) are installed in the geothermal reservoir (1); a water extraction pump (3) and a water extraction well tubing (4) are installed in the geothermal water extraction well (2); and a reinjection well tubing (17) is installed in the geothermal reinjection well (18). A heavy oil water injection well (9) and a heavy oil production well (11) are set in the shallow heavy oil layer (10); a water injection well tubing (8) is set in the heavy oil water injection well (9); and an oil production pump (12) and an oil production well tubing (13) are set in the heavy oil production well (11).

8. The system according to claim 7, characterized in that, An automatic water distribution system (6) is installed on the oil pipe connecting the geothermal water extraction well (2) and the heavy oil injection well (9).

9. The system according to claim 7, characterized in that, An oil-water separator (15) is installed on the oil pipe connecting the geothermal reinjection well (18) and the heavy oil production well (11).

10. The system according to claim 7, characterized in that, The geothermal water extraction well (2) is connected to several heavy oil injection wells (9).

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