Geothermal small well spacing taking and irrigation development method and system

Abstract

The invention discloses a geothermal small well spacing taking and filling development method and system, and relates to the technical field of geothermal development, the method comprises the following steps: step S101, developing a deployment area sand body superposition relation and distribution characteristic research, and determining a thermal storage sand space distribution rule; step S102, designing a small well spacing taking and filling well pattern according to a hot sand storage space distribution rule; s103, optimizing the small well spacing irrigation well spacing and the cold breakthrough period according to the design result of the small well spacing irrigation well pattern; and step S104, optimizing the intermittent development mode of the small-well-spacing irrigation well pair. According to the method, on the basis of fine heat storage description research, the taking and filling connectivity can be effectively improved, and the problem of small-well-spacing taking and filling cold breakthrough is solved through taking and filling parameter optimization and an intermittent mode, so that the purpose of improving the heat utilization rate is achieved, and finally the problem of poor taking and filling connectivity caused by complex heat storage sand body stacking can be greatly solved.

Description

Technical Field

[0001] The present invention relates to the field of geothermal development technology, and in particular to a geothermal small-well spacing extraction and irrigation development method and system. Background Art

[0002] The low-carbon joint station developed in 2021 is the first geothermal development test area in Liaohe for large-scale extraction and injection. The geothermal resources in the Liaohe Depression are rich in the east and poor in the west. The regional oil products are thick in the west and sparse in the east, and the supply-side matching is poor. This makes the superimposed thermal reservoir geothermal development of the third section of Shahe in the heavy oil area of ​​the western depression an option. The reservoir properties of this layer are medium, and the contact relationship of the sand body is complex. The reservoir configuration of this area is mainly side-overlapping river channel-migration type. Local water production wells are located in isolated sand bodies. The connectivity of water production wells and re-injection wells in the thermal reservoir section is poor, with a connectivity coefficient of 0.1-0.5. In addition, the poor reservoir properties of the thermal reservoir section restrict the subsequent adjustment of the layer section. The early pilot test confirmed that the connectivity of extraction and injection is difficult to guarantee under the condition of large well spacing. Therefore, it is urgent to find a new form of extraction and injection well network to improve the problem of poor extraction and injection connectivity caused by the superposition of complex thermal reservoir sand bodies. Summary of the invention

[0003] The purpose of the present invention is to provide a method and system for geothermal small well spacing extraction and injection development. The present invention relies on the research of fine heat reservoir description to effectively improve the connectivity of extraction and injection, and improve the problem of cold breakthrough of small well spacing extraction and injection through the optimization of extraction and injection parameters and intermittent mode, so as to achieve the purpose of improving heat utilization, and finally can greatly improve the problem of poor extraction and injection connectivity caused by the superposition of complex heat reservoir sand bodies. To achieve the above purpose, the present invention provides the following technical solutions:

[0004] The present invention provides a geothermal small well spacing extraction and irrigation development method, the method comprising the following steps:

[0005] A geothermal small well spacing extraction and irrigation development method, the method comprising the following steps:

[0006] Step S101, conducting research on the relationship between the superposition and distribution characteristics of sand bodies in the deployment area, and determining the spatial distribution law of the thermal sand storage;

[0007] Step S102, designing a small-well-spacing well network according to the spatial distribution law of the hot sand storage;

[0008] Step S103, optimizing the distance between wells and cold breakthrough period according to the design result of the well network with small well spacing;

[0009] Step S104, optimizing the intermittent development mode for small well spacing injection wells.

[0010] Furthermore, the step S101, conducting a study on the relationship between the superposition and distribution characteristics of the sand bodies in the deployment area and determining the spatial distribution law of the thermal sand storage, specifically includes:

[0011] Relying on seismic, well logging and mud recording data, the reservoir framework of the thermal reservoir section is established by combining well and seismic data, and isochronous stratigraphic interfaces are divided. Combined with seismic inversion technology, the contact relationship of sand bodies is described and characterized, and the spatial distribution law of sand bodies is analyzed. Based on the results of well logging interpretation, the spatial distribution law of thermal reservoir physical properties is analyzed, and the spatial distribution law of single sand bodies is described.

[0012] Furthermore, the step S102, designing a small well spacing injection and recharging well network according to the spatial distribution law of the hot sand storage, specifically includes:

[0013] Establish injection-production units of a small-well-spacing injection and well network. Deploy injection and well pairs in the same sand body according to the spatial distribution law of single sand bodies. Calculate the injection and well connectivity, conventional thickness, layer connectivity coefficient, and seepage performance in combination with the spatial distribution law of thermal reservoir physical properties. Set the injection-production well ratio according to the close distance between injection and production wells.

[0014] Furthermore, the well network injection and production unit is one of a 4-point well network injection and production unit, a 7-point well network injection and production unit or a 9-point well network injection and production unit.

[0015] Furthermore, the well network injection and production unit is a 4-point well network injection and production unit.

[0016] Furthermore, the ratio of injection-production wells is 1 to 3:1.

[0017] Furthermore, the ratio of injection to production wells is 1:1.

[0018] Furthermore, after setting the injection-production well ratio according to the proximity of the injection-production wells, it also includes setting up spare wells to dynamically adjust the period of mismatch between injection and extraction.

[0019] Furthermore, the step S103, according to the design result of the well network with small well spacing, optimizes the well spacing with small well spacing and the cold breakthrough period, specifically includes:

[0020] According to the well network design results, combined with the spatial distribution of single sand bodies and the seepage level, on the basis of fine three-dimensional geological modeling, numerical simulation of heat storage is carried out to optimize the spacing of small well spacing for injection and cold breakthrough period.

[0021] Furthermore, the step S104, optimizing the intermittent development mode for the wells with small well spacing, specifically includes:

[0022] Determine the breakthrough time and intermittent cycle of injection and drilling for intermittent development with small-well spacing.

[0023] The present invention also provides a geothermal small well spacing extraction and irrigation development system, the system comprising: a determination unit, a design unit, a first optimization unit and a second optimization unit; wherein,

[0024] Determine the unit to carry out research on the superposition relationship and distribution characteristics of sand bodies in the deployment area and determine the spatial distribution law of thermal sand storage;

[0025] Design unit, used to design the small-well spacing injection and recharging well network according to the spatial distribution law of hot sand storage;

[0026] The first optimization unit is used to optimize the distance between wells for small well spacing and the cold breakthrough period according to the design result of the well network for small well spacing;

[0027] The second optimization unit is used to optimize the intermittent development mode of small-well spacing injection wells.

[0028] Furthermore, the determining unit is specifically configured to:

[0029] Relying on seismic, well logging and mud recording data, the reservoir framework of the thermal reservoir section is established by combining well and seismic data, and isochronous stratigraphic interfaces are divided. Combined with seismic inversion technology, on the basis of sedimentary understanding, the contact relationship of sand bodies is described and characterized, and the spatial distribution law of sand bodies is analyzed. According to the results of well logging interpretation, the spatial distribution law of thermal reservoir physical properties is analyzed, and the spatial distribution law of single sand bodies is described.

[0030] Furthermore, the design unit is specifically used for:

[0031] Establish injection-production units in a small-well spacing injection and well network. Deploy injection and well pairs in the same single sand body according to the spatial distribution law of single sand bodies. Calculate the injection and injection connectivity, conventional thickness, layer connectivity coefficient, and seepage performance in combination with the spatial distribution law of thermal reservoir physical properties. Set the injection-production well ratio according to the close distance between injection and production wells.

[0032] Furthermore, the design unit is also used for:

[0033] Set up spare wells to dynamically adjust the periods of mismatch between injection and injection.

[0034] Furthermore, the first optimization unit is specifically used for:

[0035] According to the well network design results, combined with the spatial distribution of single sand bodies and the seepage level, on the basis of fine three-dimensional geological modeling, numerical simulation of heat storage is carried out to optimize the spacing of small well spacing for injection and cold breakthrough period.

[0036] Furthermore, the second optimization unit is specifically used for:

[0037] Determine the breakthrough time and intermittent cycle of injection and drilling for intermittent development with small-well spacing.

[0038] In addition, the present invention also provides a computer-readable storage medium, which stores computer instructions, and the computer instructions are used to implement the above-mentioned geothermal small-well spacing extraction and injection development method when executed by a processor.

[0039] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method for geothermal small-well spacing extraction and irrigation development when executing the computer program.

[0040] Technical effects and advantages of the present invention:

[0041] The present invention can significantly improve the problem of poor connectivity between injection and drainage caused by the superposition of complex heat storage sand bodies, thereby achieving the purpose of improving heat utilization. A new means of geothermal development of complex superimposed sand bodies is proposed in a targeted manner. Through small well spacing injection and development, the deployment of injection and drainage wells is combined with the distribution law of sand bodies to greatly increase the connectivity of injection and drainage. At the same time, combined with the periodic intermittent rotation method, the heating of the wells under the condition of small well spacing is achieved, the traditional understanding of injection and drainage well spacing is changed, and the connectivity of injection and drainage is effectively improved. Through the optimization of injection and drainage parameters and the intermittent method, the problem of cold breakthrough of injection and drainage at small well spacing is improved, and the purpose of improving heat utilization is achieved.

[0042] Other features and advantages of the present invention will be described in the following description, and partly become obvious from the description, or be understood by implementing 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

[0043] Figure 1 A flow chart of a geothermal small well spacing extraction and irrigation development method according to an exemplary embodiment of the present invention;

[0044] Figure 2 A well location map of the Dalinghe oil layer in the F block according to an exemplary embodiment of the present invention;

[0045] Figure 3 The sedimentary phase diagram of the Dalinghe oil layer in the F block according to an exemplary embodiment of the present invention;

[0046] Figure 4 This is a seismic inversion profile of wells 10-13 to 4-11 in the Dalinghe oil layer of the F block according to an exemplary embodiment of the present invention;

[0047] Figure 5 This is a heat storage cross-section diagram of wells 10-13 to 4-11 in the Dalinghe oil layer of F block according to an exemplary embodiment of the present invention;

[0048] Figure 6 The thickness diagram of the No. 1 thermal reservoir sand body of the Dalinghe oil layer in the F fault block according to an exemplary embodiment of the present invention;

[0049] Figure 7 The thickness diagram of the No. 2 thermal reservoir sand body of the Dalinghe oil layer in the F fault block according to an exemplary embodiment of the present invention;

[0050] Figure 8The thickness diagram of the No. 3 thermal reservoir sand body of the Dalinghe oil layer in the F fault block according to an exemplary embodiment of the present invention;

[0051] Fig. 9 A schematic diagram of a well network design with small well spacing according to an exemplary embodiment of the present invention;

[0052] Fig.10 This is a numerical simulation diagram of cold breakthrough after one year at a well spacing of 70 m according to an exemplary embodiment of the present invention;

[0053] Fig.11 This is a numerical simulation diagram of cold breakthrough after 1.5 years at a well spacing of 141 m according to an exemplary embodiment of the present invention;

[0054] Fig.12 This is a numerical simulation diagram of cold breakthrough after 7 years at a well spacing of 212 m according to an exemplary embodiment of the present invention;

[0055] Fig.13 This is a numerical simulation diagram of cold breakthrough after 30 years at a well spacing of 283 m according to an exemplary embodiment of the present invention;

[0056] Fig.14 It is a schematic diagram of an intermittent development method of a small-well spacing injection well pair according to an exemplary embodiment of the present invention;

[0057] Fig.15 A schematic diagram of a geothermal small-well spacing extraction and irrigation development system according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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 creative work are within the scope of protection of the present invention.

[0059] In order to solve the shortcomings of the prior art, the present invention fully combines the detailed heat storage description of the geothermal development area with the geothermal engineering design, and adopts 4 specific steps to complete the small well spacing extraction and injection development design. Figure 1 The flowchart of a method for developing geothermal areas with small well spacing is shown in the following example. Figure 1 As shown, the method comprises the following steps:

[0060] Step S101, conducting research on the relationship between the superposition and distribution characteristics of sand bodies in the deployment area, and determining the spatial distribution law of the thermal sand storage;

[0061] Step S102, designing a small-well-spacing well network according to the spatial distribution law of the hot sand storage;

[0062] Step S103, optimizing the distance between wells and cold breakthrough period according to the design result of the well network with small well spacing;

[0063] Step S104, optimizing the intermittent development mode for small well spacing injection wells.

[0064] In step S101 of the present invention, the research on the superposition relationship and distribution characteristics of sand bodies in the deployment area is carried out to determine the spatial distribution law of thermal sand storage, specifically: relying on seismic, well logging, well logging and other data, the reservoir framework of the thermal reservoir section is established by combining well-seismic data, isochronous stratigraphic interfaces are divided, and technical means such as seismic inversion are combined to describe and depict the contact relationship of sand bodies on the basis of sedimentary knowledge, analyze the spatial distribution law of sand bodies, and rely on the results of well logging interpretation to analyze the distribution law of thermal reservoir physical properties. The spatial distribution law of single sand bodies is described to lay a geological foundation for well network design.

[0065] In step S102 of the present invention, the design of the small well spacing injection well network is carried out according to the spatial distribution law of the thermal sand storage space, specifically: establishing the injection and production unit of the small well spacing injection well network, relying on the spatial distribution law of the single sand body, deploying the injection well pairs in the same single sand body, and combining the spatial distribution law of the thermal reservoir physical properties, the injection wells are as far as possible in the dominant seepage area, and the injection connectivity is precisely described and calculated. On the basis of the conventional thickness and layer connectivity coefficient calculation, the permeability evaluation is supplemented to ensure that the reinjected fluid can enter the water well after the heat supplement through the underground high-quality thermal reservoir section, and form high-temperature hot water to be produced from the water well; at the same time, according to the close distance between the injection and production wells, the injection and production well number ratio is set, and a spare well is set in the well network design to dynamically adjust the injection and injection mismatch period.

[0066] Furthermore, the well network injection and production unit is one of a 4-point well network injection and production unit, a 7-point well network injection and production unit or a 9-point well network injection and production unit.

[0067] Preferably, the well pattern injection and production unit is a 4-point well pattern injection and production unit.

[0068] Furthermore, the ratio of injection-production wells is 1 to 3:1.

[0069] Preferably, the ratio of injection wells to production wells is 1:1.

[0070] In step S103 of the present invention, the well spacing and cold breakthrough period of small well spacing are optimized according to the well network design results of small well spacing, specifically: according to the well network design results, combined with the spatial distribution of single sand bodies and the seepage level, on the basis of fine three-dimensional geological modeling, scheme design is adopted to carry out thermal reservoir numerical simulation, and the well spacing and cold breakthrough period of small well spacing are optimized. The deployment of geothermal wells for injection with small well spacing is an effective solution to solve the difficulty of re-injection. Due to the large differences in the thickness and physical properties of thermal reservoirs in different fault blocks, the actual characteristics should be comprehensively optimized in the well spacing design. At the same time, combined with the current understanding of the thermal breakthrough mechanism of indoor physical simulation, it is ensured that the temperature of the water well will not drop significantly, and the development effect of the injection well is guaranteed.

[0071] In step S104 of the present invention, the intermittent development mode of the wells with small well spacing is optimized, specifically: in the process of optimizing operation, personalized design should be carried out in combination with the ground energy demand and heat characteristics. It is mainly to optimize the intermittent development mode of the wells with small well spacing. On the basis of clarifying the breakthrough time of injection and extraction, the intermittent cycle is determined to form a rotation injection and extraction system.

[0072] Example:

[0073] Taking the Dalinghe oil layer in F fault block as an example, the F fault block is geographically adjacent to the H plant joint station and structurally located in the middle section of the western slope of the western depression of Liaohe fault depression. The target layer of this geothermal study is the third section of Shahe formation. After 30 years of development, the lower oil layer of this block has been exhausted and is in a state of being scrapped. The wells that have been completed in the early stage have confirmed that the upper Dalinghe oil layer has rich thermal storage resources and has development potential.

[0074] Figure 2 The well location map of the Dalinghe oil layer in the F block according to the exemplary embodiment of the present invention is shown in FIG. Figure 2 As shown in the figure, this figure reflects the structural morphology of the top of the main heat reservoir section and the development of faults on the edge. Its basic working method is to determine the marker layer through the curve morphology on a single well, determine the curve characteristics of the top of the heat reservoir target layer to divide the strata, and establish an isochronous framework in combination with seismic interpretation data, which is also the basis for subsequent temperature field prediction.

[0075] In order to implement the thermal reserve resources in the hot well deployment area, this method is used to change the geothermal development dilemma of the superimposed thermal reservoir in the third section of the Shahejie Formation, and an innovative method of geothermal small well spacing extraction and injection development is proposed. The traditional understanding of extraction and injection well spacing is changed, the extraction and injection connectivity is effectively improved, and the problem of cold breakthrough of small well spacing extraction and injection is improved through the optimization of extraction and injection parameters and intermittent methods.

[0076] Step S101: Conduct research on the relationship between the sand bodies and their distribution characteristics in the deployment area to determine the spatial distribution law of the thermal sand storage.

[0077] The main purpose is to model phase-controlled thermal reservoirs. Figure 3The sedimentary phase diagram of the Dalinghe oil layer in the F block of the exemplary embodiment of the present invention is as follows: Figure 3 As shown in the figure, this figure is drawn based on the curve morphological characteristics of different sedimentary microfacies in a single well, analyzing their distribution laws on the plane, and implementing the distribution laws of river channels and between river channels, laying the foundation for the subsequent overall deployment of well groups.

[0078] Figure 4 This is a seismic inversion profile of wells 10-13 to 4-11 in the Dalinghe oil layer of the F block according to an exemplary embodiment of the present invention. Figure 4 As shown in the figure, this is a seismic inversion profile formed by three-dimensional seismic data through professional software. The different colors in the figure reflect the different rock properties underground. Since seismic data is the only basis for determining the distribution of sand bodies between wells, the contact relationship of sand bodies between wells can be predicted by combining completed drilling and seismic data, and deducing the unknown from the known.

[0079] Figure 5 This is a heat storage cross-section diagram of wells 10-13 to 4-11 in the Dalinghe oil layer of the F block according to an exemplary embodiment of the present invention. Figure 5 As shown, the figure is based on Figure 4 The prediction results of the inter-well sand body contact relationship are based on the single well thermal reservoir division. The distribution of sand bodies on the well-connected sections is expressed in the form of maps. The result is to characterize the spatial contact relationship of sand bodies of different periods and lay the foundation for the plane characterization of sand bodies of different periods. Relying on the regional sedimentary knowledge, the spatial distribution law of thermal reservoir sand is implemented. The third section of the sand belongs to the underwater fan subfacies deposition. The thermal reservoir distribution has obvious phase-controlled characteristics. The material source comes from the north. The thermal reservoir is controlled by sedimentation, and the thick value area is concentrated on the east and west sides.

[0080] Figure 6 This is a thickness diagram of the No. 1 thermal reservoir sand body of the Dalinghe oil layer in the F fault block according to an exemplary embodiment of the present invention. Figure 7 This is a thickness diagram of the No. 2 thermal reservoir sand body of the Dalinghe oil layer in the F block according to an exemplary embodiment of the present invention. Figure 8 The thickness diagram of the No. 3 thermal reservoir sand body in the Dalinghe oil layer of the F block according to the exemplary embodiment of the present invention is shown in FIG. Figure 6-8 As shown, in Figure 5 Based on the research, the contact relationship of the sand bodies was determined through multiple well-connected thermal reservoir profiles, and the plane distribution range of the No. 1 sand body was clarified, which provided the basis for the deployment of the well group. The area is controlled by sedimentation and is composed of three sets of overlapping sand bodies, with No. 1 and No. 2 overlapping in the west and No. 3 in the east being low, thick and high, and thin.

[0081] Step S102: designing a small-well-spacing injection and extraction well network according to the spatial distribution law of the hot sand storage.

[0082] Fig. 9 Schematic diagram of a well network design with small well spacing according to an exemplary embodiment of the present invention. Fig. 9As shown, the well group design mainly includes three types of water wells, recharge wells and spare wells. The water wells are deployed in the same period of thermal storage sand bodies to ensure the connectivity of water intake and injection. This application takes the basic 4-point well network injection and production unit as the prototype. Considering the close distance between injection and production wells, the injection and production well ratio is set to 1:1, and a spare well is set in the 4-point well network to dynamically adjust the period of mismatch between water intake and injection.

[0083] Step S103: Optimize the spacing of wells for small well spacing and the cold breakthrough period according to the design result of the well network for small well spacing.

[0084] Fig.10 This is a numerical simulation diagram of cold breakthrough after one year at a well spacing of 70 m according to an exemplary embodiment of the present invention. Fig.11 This is a numerical simulation diagram of cold breakthrough after 1.5 years at a well spacing of 141 m according to an exemplary embodiment of the present invention. Fig.12 This is a numerical simulation diagram of cold breakthrough after 7 years at a well spacing of 212 m according to an exemplary embodiment of the present invention. Fig.13 This is a numerical simulation diagram of cold breakthrough after 30 years at a well spacing of 283 m according to an exemplary embodiment of the present invention. Figure 10-13 As shown in the figure, through the CMG professional numerical simulation software platform, the deployment design is actually simulated to determine the law of reinjection water spreading in the thermal storage space and implement the cold breakthrough limit. The previous numerical simulation confirmed that under the condition of setting a drop of 20℃ as the cold breakthrough, the medium-porosity and medium-permeability reservoir in the third section of the Shahejie Formation experienced a cold breakthrough after 1 year at a well distance of 70m, after 1.5 years at a well distance of 141m, after 7 years at a well distance of 212m, and after 30 years at a well distance of 283m.

[0085] The distance between the standby well and the surrounding wells is set at 283m, and the distance between the injection wells is set at 10 to 30m considering the actual available wells on site.

[0086] Step S104, optimizing the intermittent development mode for small well spacing injection wells.

[0087] Fig.14 Schematic diagram of intermittent development of small well spacing injection wells according to an exemplary embodiment of the present invention. Fig.14As shown in the figure, the small wells have limited space for heating and the time for the reinjected water to reach the water wells is short, so multiple wells need to be rotated to give a certain temperature recovery period. This figure is a schematic representation of the intermittent development system. The full life cycle is described as follows. In the first stage, water well 1 is produced, and the water is reinjected into other blocks to reduce the formation pressure in the geothermal development area. After the water intake volume drops significantly, water extraction is stopped. In the second stage, water well 2 is produced, and the water is reinjected into reinjection well 1. Because of the formation deficit formed around it, reinjection will be better guaranteed. After the water intake volume drops significantly, water extraction and reinjection will be stopped. In the third stage, water well 3 is produced, and the water is reinjected into reinjection well 2. Because of the formation deficit formed around it, reinjection will be better guaranteed. After the water intake volume drops significantly, water extraction and reinjection will be stopped. In the fourth stage, water well 1 is produced, and the water is reinjected into reinjection well 3. Because of the formation deficit formed around it, reinjection will be better guaranteed. After the water intake volume drops significantly, water extraction and reinjection will be stopped. This reciprocating process allows the recharge water to stay underground for a certain period of time to ensure the heating effect.

[0088] In addition, the present invention also provides a geothermal small well spacing extraction and irrigation development system. Fig.15 FIG. 1 is a schematic diagram of a geothermal small well spacing extraction and irrigation development system according to an exemplary embodiment of the present invention. Fig.15 As shown, the system includes: a determination unit 11, a design unit 12, a first optimization unit 13 and a second optimization unit 14; wherein the determination unit 11 is used to carry out research on the superposition relationship and distribution characteristics of sand bodies in the deployment area, and determine the spatial distribution law of the thermal sand storage; the design unit 12 is used to design a small well spacing injection well network according to the spatial distribution law of the thermal sand storage; the first optimization unit 13 is used to optimize the small well spacing injection well spacing and the cold breakthrough period according to the design result of the small well spacing injection well network; the second optimization unit 14 is used to optimize the intermittent development mode of the small well spacing injection wells.

[0089] Furthermore, the determination unit 11 is specifically used for: relying on seismic, well logging and mud logging data, combining well and seismic data to establish a reservoir framework for the thermal reservoir section, dividing isochronous stratigraphic interfaces, combining seismic inversion technology, based on sedimentary knowledge, describing and depicting the contact relationship of sand bodies, analyzing the spatial distribution of sand bodies, analyzing the spatial distribution of thermal reservoir physical properties based on the logging interpretation results, and describing the spatial distribution of single sand bodies.

[0090] Furthermore, the design unit 12 is specifically used to: establish an injection-production unit of a small-well-spacing injection and extraction well network, deploy injection and extraction well pairs in the same single sand body according to the spatial distribution law of a single sand body, calculate the injection and extraction connectivity, conventional thickness, layer connectivity coefficient, and seepage performance in combination with the spatial distribution law of thermal reservoir physical properties; and set the injection-production well number ratio according to the close distance between injection and production wells.

[0091] Furthermore, the design unit is also used to set up spare wells and dynamically adjust the period of mismatch between injection and injection.

[0092] Furthermore, the first optimization unit 13 is specifically used to: carry out thermal storage numerical simulation based on fine three-dimensional geological modeling according to the well pattern design results, combined with the spatial distribution of single sand bodies and the seepage level, to optimize the small well spacing and injection well spacing optimization and cold breakthrough period.

[0093] Furthermore, the second optimization unit 14 is specifically used to determine the breakthrough time and intermittent cycle of the injection and extraction wells with small well spacing for intermittent development.

[0094] The present invention also provides a computer-readable storage medium, which stores computer instructions, and the computer instructions are used to enable a processor to implement a geothermal small-well spacing extraction and injection development method as described above when executed.

[0095] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, a geothermal small well spacing extraction and irrigation development method as described above is implemented.

[0096] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A geothermal small well spacing extraction and irrigation development method, characterized in that: The method comprises the following steps: Step S101, conducting research on the relationship between the superposition and distribution characteristics of sand bodies in the deployment area, and determining the spatial distribution law of the thermal sand storage; Step S102, designing a small-well-spacing well network according to the spatial distribution law of the hot sand storage; Step S103, optimizing the distance between wells and cold breakthrough period according to the design result of the well network with small well spacing; Step S104, optimizing the intermittent development mode for small well spacing injection wells.

2. A geothermal small well spacing extraction and irrigation development method according to claim 1, characterized in that: The step S101, conducting a study on the relationship between the superposition and distribution characteristics of the sand bodies in the deployment area and determining the spatial distribution law of the thermal sand storage, specifically includes: Relying on seismic, well logging and mud recording data, the reservoir framework of the thermal reservoir section is established by combining well and seismic data, and isochronous stratigraphic interfaces are divided. Combined with seismic inversion technology, the contact relationship of sand bodies is described and characterized, and the spatial distribution law of sand bodies is analyzed. Based on the results of well logging interpretation, the spatial distribution law of thermal reservoir physical properties is analyzed, and the spatial distribution law of single sand bodies is described.

3. A geothermal small well spacing extraction and irrigation development method according to claim 1, characterized in that: The step S102, designing a small well spacing injection and recharging well network according to the spatial distribution law of the hot sand storage, specifically includes: Establish injection-production units of a small-well-spacing injection and well network. Deploy injection and well pairs in the same sand body according to the spatial distribution law of single sand bodies. Calculate the injection and well connectivity, conventional thickness, layer connectivity coefficient, and seepage performance in combination with the spatial distribution law of thermal reservoir physical properties. Set the injection-production well ratio according to the close distance between injection and production wells.

4. A geothermal small well spacing extraction and irrigation development method according to claim 3, characterized in that: The well network injection and production unit is one of a 4-point well network injection and production unit, a 7-point well network injection and production unit or a 9-point well network injection and production unit.

5. A geothermal small well spacing extraction and irrigation development method according to claim 3, characterized in that: The well network injection and production unit is a 4-point well network injection and production unit.

6. A geothermal small well spacing extraction and irrigation development method according to claim 3, characterized in that: The ratio of injection-production wells is 1 to 3:

1.

7. A geothermal small well spacing extraction and irrigation development method according to claim 3, characterized in that: The ratio of injection and production wells is 1:

1.

8. A geothermal small well spacing extraction and irrigation development method according to claim 3, characterized in that: After setting the ratio of injection and production wells according to the proximity of the injection and production wells, it also includes setting up spare wells to dynamically adjust the period of mismatch between injection and production.

9. A geothermal small well spacing extraction and irrigation development method according to claim 1, characterized in that: The step S103, according to the design result of the well network with small well spacing, optimizes the well spacing with small well spacing and the cold breakthrough period, specifically includes: According to the well network design results, combined with the spatial distribution of single sand bodies and the seepage level, on the basis of fine three-dimensional geological modeling, numerical simulation of heat storage is carried out to optimize the spacing of small well spacing for injection and cold breakthrough period.

10. A geothermal small well spacing extraction and irrigation development method according to claim 1, characterized in that: The step S104, optimizing the intermittent development mode for the small well spacing injection wells, specifically includes: Determine the breakthrough time and intermittent cycle of injection and drilling for intermittent development with small-well spacing.

11. A geothermal small well spacing extraction and irrigation development system, characterized in that: The system comprises: a determination unit, a design unit, a first optimization unit and a second optimization unit; wherein, Determine the unit to carry out research on the superposition relationship and distribution characteristics of sand bodies in the deployment area and determine the spatial distribution law of thermal sand storage; Design unit, used to design the small-well spacing injection and recharging well network according to the spatial distribution law of hot sand storage; The first optimization unit is used to optimize the distance between wells for small well spacing and the cold breakthrough period according to the design result of the well network for small well spacing; The second optimization unit is used to optimize the intermittent development mode of small-well spacing injection wells.

12. A geothermal small well spacing extraction and irrigation development system according to claim 11, characterized in that: The determining unit is specifically used for: Relying on seismic, well logging and mud recording data, the reservoir framework of the thermal reservoir section is established by combining well and seismic data, and isochronous stratigraphic interfaces are divided. Combined with seismic inversion technology, on the basis of sedimentary understanding, the contact relationship of sand bodies is described and characterized, and the spatial distribution law of sand bodies is analyzed. According to the results of well logging interpretation, the spatial distribution law of thermal reservoir physical properties is analyzed, and the spatial distribution law of single sand bodies is described.

13. A geothermal small well spacing extraction and irrigation development system according to claim 11, characterized in that: The design unit is specifically used for: Establish injection-production units in a small-well spacing injection and well network. Deploy injection and well pairs in the same single sand body according to the spatial distribution law of single sand bodies. Calculate the injection and injection connectivity, conventional thickness, layer connectivity coefficient, and seepage performance in combination with the spatial distribution law of thermal reservoir physical properties. Set the injection-production well ratio according to the close distance between injection and production wells.

14. A geothermal small well spacing extraction and irrigation development system according to claim 13, characterized in that: The design unit is also used to: Set up spare wells to dynamically adjust the periods of mismatch between injection and injection.

15. The geothermal small well spacing extraction and irrigation development system according to claim 11, characterized in that: The first optimization unit is specifically used for: According to the well network design results, combined with the spatial distribution of single sand bodies and the seepage level, on the basis of fine three-dimensional geological modeling, numerical simulation of heat storage is carried out to optimize the spacing of small well spacing for injection and cold breakthrough period.

16. A geothermal small well spacing extraction and irrigation development system according to claim 11, characterized in that: The second optimization unit is specifically used for: Determine the breakthrough time and intermittent cycle of injection and drilling for intermittent development with small-well spacing.

17. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement a geothermal small-well spacing extraction and injection development method as described in any one of claims 1-10 when executed.

18. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, a geothermal small-well spacing extraction and irrigation development method as described in any one of claims 1 to 10 is implemented.

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