Low-temperature water-bearing layer perforation water release mixed water increasing device

Abstract

The application relates to a low-temperature aquifer water-releasing and water-mixing device, and relates to the technical field of geothermal development, which comprises a middle-deep geothermal well, a cement well cementing is arranged around the middle-deep geothermal well, the bottom of the cement well cementing is connected with a first heat reservoir, the middle part of the cement well cementing penetrates a second heat reservoir, a perforation hole is arranged on the cement well cementing, the perforation hole corresponds to the second heat reservoir, the perforation hole on the cement well cementing extends from the well pipe wall to the second heat reservoir, water-mixing and yield increase are realized through innovative perforation technology, and the upper aquifer has high water yield and low water temperature, the two can be mixed through the perforation process, the water yield is increased, the middle-low temperature mixed water meets the requirements, the problem that the geothermal well has high water temperature but insufficient water yield is effectively solved, and the device exhibits obvious advantages in aspects of improving resource utilization efficiency, reducing development cost, enhancing environmental adaptability and the like.

Description

Technical Field

[0001] This invention relates to the field of geothermal development technology, and more particularly to a low-temperature aquifer perforation water release and mixing device. Background Technology

[0002] Geothermal energy is a green and clean resource, and accelerating its development is an important way to achieve dual-carbon goals. The development of medium-deep geothermal energy mainly focuses on hydrothermal geothermal resources, which have the advantages of high temperature and large water volume; a single well can provide heating for over 100,000 square meters of building area. The acquisition of hydrothermal geothermal energy is primarily achieved through geothermal wells connecting to underground thermal energy sources. In traditional geothermal resource development, the filter pipe process is a commonly used well completion method, but this process has limitations when facing complex geothermal structures. When geothermal wells reach the target layer, they often encounter situations where the water temperature meets the standard but the water volume is insufficient, failing to meet actual development needs and seriously affecting the effective utilization and development benefits of geothermal resources. Because geothermal reservoirs are hidden underground, accurate well location detection through geophysical and geochemical exploration is difficult. Furthermore, damage from deep fault structures can lead to situations where the actual exposed aquifer has a high water temperature but low water volume, failing to meet the requirements for geothermal resource development and utilization.

[0003] In summary, there is an urgent need for a low-temperature aquifer perforation and water release mixing and enhancement device to solve the above problems. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a scientifically optimized low-temperature aquifer perforation water release and mixing device to solve the problem that the water temperature meets the standard but the water volume is insufficient in the existing geothermal water development process, which makes it difficult to meet the actual development needs and seriously affects the effective utilization and development benefits of geothermal resources.

[0005] According to a first aspect of the present invention, the present invention provides a low-temperature aquifer perforation water release and mixing water enhancement device, comprising a medium-deep geothermal well, wherein cement cementing is provided around the medium-deep geothermal well; the bottom of the cement cementing is connected to a first thermal reservoir, the middle part of the cement cementing penetrates a second thermal reservoir, and perforations are provided on the cement cementing, the perforations corresponding to the second thermal reservoir.

[0006] A sedimentation pipe is connected to the bottom of the cement cement well. A pipe plug is fixedly installed at the center of the bottom of the sedimentation pipe, and a pre-reserved pocket is provided below the pipe plug. A bottom water stop is provided at the top of the sedimentation pipe. The bottom of the cemented well is provided with a water filter pipe, which includes a centralizer and gravel. The gravel is filled inside the water filter pipe, and the centralizer is fixedly installed inside the gravel. The cemented well has a well casing wall on its inner wall, and the perforation holes on the cemented well extend from the well casing wall to the second thermal reservoir; a pump chamber is installed at the top of the cemented well.

[0007] In a preferred embodiment of the present invention, the medium-deep geothermal well adopts a two-stage drilling structure, with the casing serving as both the first stage and the second stage for the installation of sedimentation pipes, well walls, and filter pipes.

[0008] Compared with the prior art, the technical solution of this application has the following beneficial effects: This application presents an improved well completion process that utilizes innovative perforation technology to achieve water mixing and increased production, thereby meeting the desired objectives. This improved well completion process addresses the common problem of high water temperature but high water volume in upper aquifers. By mixing the two through perforation, the water production is increased, achieving medium-to-low temperature mixed water to meet requirements. This effectively solves the problem of high water temperature but insufficient water production in geothermal wells, demonstrating significant advantages in improving resource utilization efficiency, reducing development costs, and enhancing environmental adaptability. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of a low-temperature aquifer perforation water release and mixing device in one embodiment of this application.

[0010] Figure descriptions: 1. Medium-deep geothermal well; 2. Cement cementing; 3. Filter pipe; 4. Centralizer; 5. Gravel; 6. First geothermal reservoir; 7. Sedimentation pipe; 8. Pipe plug; 9. Bottom stop; 10. Reserved pocket; 11. Second geothermal reservoir; 12. Perforation hole; 13. Pump chamber; 14. Well wall. Detailed Implementation

[0011] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments. Example 1

[0012] A low-temperature aquifer perforation water release mixing and water enhancement device, such as Figure 1 As shown, the system includes a medium-deep geothermal well 1, around which cemented wells 2 are arranged; the exterior of the cemented wells 2 is a soil environment; the bottom of the cemented wells 2 is connected to a first thermal reservoir 6, and the middle of the cemented wells 2 penetrates a second thermal reservoir 11; the cemented wells 2 are provided with perforations 12, which correspond to the second thermal reservoir 11.

[0013] The bottom of the cement cementing well 2 is connected to a sedimentation pipe 7, a pipe plug 8 is fixedly installed at the bottom center of the sedimentation pipe 7, and a reserved pocket 10 is provided below the pipe plug 8; a bottom water stop 9 is provided at the top of the sedimentation pipe 7. The bottom of the cement cementing well 2 is provided with a water filter pipe 3. The water filter pipe 3 includes a centralizer 4 and gravel 5. The gravel 5 is filled inside the water filter pipe 3, and the centralizer 4 is fixedly installed inside the gravel 5. The cemented well 2 has a well casing wall 14 on its inner wall, and the perforation holes 12 on the cemented well 2 extend from the well casing wall 14 to the second thermal reservoir 11; a pump chamber 13 is installed on the top of the cemented well 2.

[0014] In a preferred embodiment of the present invention, the medium-deep geothermal well 1 adopts a two-stage drilling structure, with the casing serving as the pump chamber 13 in one stage and the sedimentation pipe 7, well wall 14, and filter pipe 3 being lowered in the other stage.

[0015] The technical principle employed in this invention is as follows: The completion process for the medium-deep hydrothermal geothermal well 1 adopts the filter pipe 3 well completion process. After the design is completed, the target layer for drilling and mining is the first geothermal reservoir 6. A two-stage drilling structure is adopted. The first stage casing also serves as the pump chamber 13, and the second stage runs in the sedimentation pipe 7, well wall 14, and filter pipe 3. First, the bottom sedimentation pipe 7, pipe plug 8, and other components are connected and run into the well to settle impurities and seal the bottom of the well 9. Then, the filter pipe 3 is connected. The filter pipe 3 needs to be filled with gravel 5 to enhance the filtration effect. The filling process of gravel 5 needs to be strictly controlled to ensure uniform and dense filling and to prevent voids from affecting the filtration performance. When running the filter pipe 3, the centralizer 4 plays an important role. The centralizer 4 ensures that the filter pipe 3 is centered in the well, avoids friction damage between the pipe and the well wall, and ensures that a uniform cement ring can be formed during subsequent cementing, thereby improving the cementing quality. After the pipe is installed, cement cementing 2 is carried out. Cement slurry is injected into the annular space between the well wall and the pipe. After the cement slurry solidifies, a solid cement ring is formed, which firmly fixes the pipe in the well and also acts as a seal to prevent the crossflow of fluids from different formations.

[0016] After completing the above well completion process, during the depressurization test of the first geothermal reservoir 6, a situation arose where the water temperature was high but the water volume was insufficient. Therefore, a perforation process was added. Using specialized perforation equipment, perforations were performed at the location corresponding to the upper aquifer, the second geothermal reservoir 11, forming perforation holes 12. This connected the upper aquifer with the well, enabling the mixing of cold water with the target hot water layer, thereby increasing production. Throughout the process, the tubing installation process ensured the accurate and secure installation of the filter pipe 3, pump pipe, and other tubing materials, creating the necessary conditions for perforation and water mixing to increase production. The perforation process, based on the tubing installation results, further modified and optimized the geothermal well. The two processes complemented each other, jointly achieving the goal of improving the well completion process.

[0017] This invention presents a method for increasing water production through perforation in low-temperature aquifers. From a technical principle perspective, this process breaks through the traditional model of relying solely on the target layer for water extraction. When drilling into the target layer reveals high water temperature but insufficient water volume, precise perforation operations are performed in the upper aquifer to open a channel between the upper aquifer and the target layer. The cold water from the upper aquifer and the hot water from the target layer naturally mix within the well, not only increasing the total water output of the geothermal well but also effectively controlling the temperature of the produced water by adjusting the mixing ratio of cold and hot water, thus achieving more suitable development and utilization standards and enabling more flexible and efficient development of geothermal resources.

[0018] In terms of resource utilization efficiency, this technology significantly improves the production capacity of geothermal wells. Compared to traditional filter pipe technology, which cannot effectively solve the problem of insufficient water supply, some geothermal wells, despite possessing usable thermal energy, cannot be fully developed due to water limitations. This technology, through water mixing to increase production, enables previously low-yield or even undevelopable geothermal wells to achieve effective output, fully tapping the potential of geothermal resources and improving the overall utilization rate of geothermal resources.

[0019] From a cost control perspective, this technology effectively reduces the development cost of geothermal resources. Traditional methods often require re-drilling or employing complex injection enhancement measures when water shortages occur, consuming significant manpower, resources, and time, with uncertain results. This improved well completion technology, however, modifies existing wells through perforation, eliminating the need for re-drilling and greatly reducing drilling costs. Furthermore, precise perforation and mixing techniques minimize equipment downtime and maintenance costs due to insufficient water supply, optimizing the development process and lowering overall development costs.

[0020] In terms of environmental adaptability and sustainability, this technology offers greater flexibility and stability. Geothermal structures are complex and varied, and geothermal wells in different regions face varying water volume and temperature challenges. This technology, through perforation in the upper aquifer to achieve water mixing and enhanced production, allows for flexible adjustment of perforation location, number, and parameters based on the specific conditions of different geothermal wells. This adapts to complex geological conditions and ensures long-term stable production from geothermal wells. This approach avoids over-exploitation of geothermal reservoirs and enables the sustainable development and utilization of geothermal resources, aligning with the requirements of green energy development.

[0021] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A low-temperature aquifer perforation water release and mixing device, comprising a medium-deep geothermal well (1), wherein cemented wells (2) are provided around the medium-deep geothermal well (1); characterized in that: The bottom of the cement cement well (2) is connected to the first thermal reservoir (6), and the middle part of the cement cement well (2) penetrates the second thermal reservoir (11). The cement cement well (2) is provided with perforation holes (12), which correspond to the second thermal reservoir (11).

2. The low-temperature aquifer perforation water release and mixing device according to claim 1, characterized in that: The bottom of the cement cementing well (2) is connected to a sedimentation pipe (7), and a pipe plug (8) is fixedly installed at the bottom center of the sedimentation pipe (7). A reserved pocket (10) is provided below the pipe plug (8); a bottom water stop (9) is provided at the top of the sedimentation pipe (7).

3. The low-temperature aquifer perforation water release and mixing device according to claim 2, characterized in that: The bottom of the cement cementing well (2) is provided with a water filter pipe (3), which includes a centralizer (4) and gravel (5). The gravel (5) is filled inside the water filter pipe (3), and the centralizer (4) is fixedly installed inside the gravel (5).

4. The low-temperature aquifer perforation water release and mixing device according to claim 3, characterized in that: The inner wall of the cement cementing well (2) is provided with a well pipe wall (14), and the perforation holes (12) on the cement cementing well (2) extend from the well pipe wall (14) to the second thermal reservoir (11).

5. The low-temperature aquifer perforation water release mixing and water enhancement device according to claim 4, characterized in that: The top of the cement cementing well (2) is equipped with a pump chamber (13).

6. The low-temperature aquifer perforation water release and mixing device according to claim 5, characterized in that: The medium-deep geothermal well (1) adopts a two-stage drilling structure. The first stage casing also serves as the pump chamber (13), and the second stage is used to lower the sedimentation pipe (7), well wall (14), and filter pipe (3).

Images