Trajectory design method for highly-deviated well of sand-coal superimposed gas reservoir and related device

Abstract

The invention belongs to the technical field of natural gas exploration and development, and discloses a trajectory design method and related device for a highly-deviated well of a sand-coal superimposed gas reservoir, and the method comprises the steps: obtaining the information of a drilled well in a target area, predicting the plane distribution characteristics of a reservoir, and analyzing the geological adaptability; according to reservoir plane distribution characteristics and geological adaptability, determining an optimal trajectory of each gas-bearing layer section in the target area; and according to the determined optimal trajectory, designing a gas production process, a well drilling process and a transformation process of the highly-deviated well, and completing trajectory design of the highly-deviated well of the sand-coal superimposed gas reservoir. According to the method, multiple layers of differentiated unconventional sand coal reservoirs are utilized to the maximum extent, and the method has the advantages of being large in inclination, large in well control reserves, safe and reliable in drilling and production, environmentally friendly, sustainable and the like. The contact area of a gas storage layer can be effectively enlarged, the gas storage layer can be better penetrated, more oil and gas reserves can be obtained, unconventional oil and gas resources difficult to exploit can be better exploited, and the oil and gas exploitation efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of natural gas exploration and development technology, and relates to a trajectory design method and related equipment for highly deviated wells in coal-sand composite gas reservoirs. Background Technology

[0002] The eastern Ordos Basin, as one of China's important energy bases, boasts a wide distribution of multi-layered sandstone gas reservoirs with substantial reserves. In recent years, a series of development technologies have been developed, leading to profitable development. However, with the gradual advancement of exploration and development, new gas reservoirs in vertically superimposed coal and limestone formations have also shown considerable potential. These new reservoirs exhibit significant differences in geological characteristics, reservoir properties, and fluid properties compared to sandstone gas reservoirs; therefore, traditional development technologies and well type selections may not be entirely applicable.

[0003] Choosing the right well type is a crucial issue in the development of all gas fields. Currently, the development model for tight sandstone gas reservoirs has gone through three stages: from the early "large cluster vertical / directional well groups" to "single-layer horizontal well development targeting advantageous areas" and then to "exploration of three-dimensional horizontal well development," achieving efficient development for multi-layered, single-prime, and multi-prime-layer gas reservoirs, respectively. With the emerging potential of new gas reservoirs in coal and limestone fields, it is necessary to actively conduct trials of new well types with high deflection to explore new avenues for efficient development.

[0004] Currently, the research and application of highly deviated well technology are becoming increasingly widespread both domestically and internationally. However, these technologies are only applicable to single coal-bearing reservoirs or utilize horizontal wells to develop unconventional gas reservoirs of multiple types, without considering well types for the coordinated development of sandstone and coal-bearing gas reservoirs. The efficient and precise development of multi-layered, superimposed, multi-type unconventional gas reservoirs of multiple types places increasingly higher demands on well type selection and deployment models. To ensure the optimal match between geological targets and development methods, efficiently utilize the geological reserves of multi-layered, superimposed, multi-type unconventional gas reservoirs of multiple types, and improve recovery rates, the optimization design of highly deviated wells is urgently needed. Summary of the Invention

[0005] The purpose of this invention is to provide a trajectory design method and related apparatus for highly deviated wells in sandstone and coal-coal composite gas reservoirs, solving the problem that existing technologies do not consider the synergistic development and utilization of multiple resources in sandstone and coal-coal composite gas reservoirs.

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

[0007] A trajectory design method for highly deviated wells in coal-sand composite gas reservoirs includes:

[0008] Obtain information on drilled wells within the target area, predict reservoir planar distribution characteristics, and analyze geological adaptability;

[0009] Based on the reservoir's planar distribution characteristics and geological adaptability, the optimal trajectory of each gas-bearing stratum within the target area is determined;

[0010] Based on the determined optimal trajectory, design the gas production technology, drilling technology and stimulation technology for highly deviated wells, and complete the trajectory design for highly deviated wells in coal-sand composite gas reservoirs.

[0011] Furthermore, the drilled well information includes the effective thickness, porosity, permeability, and saturation of each gas-bearing layer in the completed skeleton wells.

[0012] Furthermore, the method for predicting the reservoir planar distribution characteristics is as follows:

[0013] By organizing and analyzing the drilling information within the target area, and combining it with comparisons with adjacent wells, geostatistical methods are used, along with variograms, kriging techniques, and stochastic simulation techniques, to predict the planar distribution characteristics of reservoirs within the target area.

[0014] Furthermore, the method for analyzing the geological adaptability is as follows:

[0015] Based on the prediction results of the reservoir planar distribution characteristics, the reservoir parameters of each gas-bearing section in the vertical direction are determined. Combined with the inter-layer difference coefficient, the co-production section is determined to avoid inter-layer interference.

[0016] The reservoir parameters include tight gas-bearing sandstone ≥8m, coal and rock thickness ≥6m, gas-bearing section vertical depth of 2200~2500m and vertical thickness >200m.

[0017] Furthermore, the interlayer difference coefficient is:

[0018]

[0019] Where i represents the stratigraphic segment, i = 1, 2, 3, ..., n, D i P represents the inter-layer difference coefficient. i K represents formation pressure. i This indicates the penetration rate.

[0020] Furthermore, the optimal trajectory determination process for each gas-bearing layer segment within the target area is as follows:

[0021] Based on the predicted reservoir planar distribution characteristics and combined with the reservoir parameters of each gas-bearing section in the vertical direction, different well inclinations for target entry are designed. The inclination thickness of the gas-bearing section for target entry is calculated using the trigonometric function method to determine the optimal well inclination for the target entry section. Then, based on the vertical depth of the underlying gas-bearing section, the optimal well inclination for each gas-bearing section is determined in turn.

[0022] Furthermore, the modification process is a combination of pressure and reaction, modifying 3 to 5 sections of coal-rock section for production, and modifying 2 to 3 sections of multi-layered sandstone section for production.

[0023] A trajectory design system for highly deviated wells in coal-sand composite gas reservoirs includes:

[0024] The acquisition module is used to acquire drilling information within the target area, predict reservoir planar distribution characteristics, and analyze geological adaptability.

[0025] The trajectory module is used to determine the optimal trajectory of each gas-bearing stratum within the target area based on the reservoir's planar distribution characteristics and geological adaptability.

[0026] The design module is used to design the gas production process, drilling process and stimulation process of the highly deviated well based on the determined optimal trajectory, and to complete the trajectory design of the highly deviated well in the coal-sand composite gas reservoir.

[0027] A terminal device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method.

[0028] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] This invention provides a trajectory design method for highly deviated wells in coal-sand composite gas reservoirs. By acquiring information on drilled wells within the target area, predicting the reservoir's planar distribution characteristics, and analyzing geological adaptability, the optimal trajectory for each gas-bearing section within the target area is determined. Based on the determined optimal trajectory, the gas production, drilling, and stimulation processes for the highly deviated wells are designed, thus completing the trajectory design for highly deviated wells in coal-sand composite gas reservoirs. This invention is based on multiple disciplines and parameters, including geology and technology, and fully considers the geological and technological adaptability of highly deviated wells for the coordinated development of sand and coal. It also specifically studies the different geological and production characteristics between tight sandstone and coal, fully considering the applicability of geological characteristics, drilling, production, and fracturing technologies. This innovative, stepped trajectory design method for highly deviated wells in the development of multi-layered coal-sand composite unconventional gas reservoirs enables the efficient development of multi-layered unconventional reservoirs. The stepped trajectory design of this invention for highly deviated wells employs a stepped, incremental trajectory to maximize the utilization of multiple, differentiated unconventional sand-coal reservoirs. This represents a significant technological innovation for the collaborative development of sand-coal composite gas reservoirs, offering advantages such as high deviation, large well-controlled reserves, safe and reliable drilling and production, and environmental sustainability. It effectively expands the contact area of ​​the gas reservoir, allowing for better penetration and the acquisition of more oil and gas reserves. Therefore, it can better exploit difficult-to-access unconventional oil and gas resources, improving oil and gas extraction efficiency. In future development, it can be widely applied to the development of sand-coal composite gas reservoirs, offering universal reference value and applicability to all similar gas reservoirs, with a huge market potential. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the trajectory design method for a highly deviated well in a coal-sand composite gas reservoir according to the present invention.

[0033] Figure 2 This is a graph showing the relationship between the slope thickness and vertical thickness of the strata under different inclinations according to the present invention.

[0034] Figure 3 This is a schematic diagram of the stepped high-angle wellbore trajectory design of the present invention.

[0035] Figure 4 This is a schematic diagram of the trajectory of a highly deviated well in a coal-sand composite gas reservoir according to the present invention.

[0036] Figure 5 This is a diagram showing the relationship between the marker layers of adjacent wells in the dual 47-58X4 target-guided system in Embodiment 1 of the present invention.

[0037] Figure 6 This is the trajectory design diagram of the double 47-58X4 high-angle well in Embodiment 1 of the present invention.

[0038] Figure 7 This is a tracking diagram of the actual drilling trajectory of the double 47-58X4 horizontal section in Embodiment 1 of the present invention.

[0039] Figure 8 This is a schematic diagram of the trajectory design system for a highly deviated well in a coal-sand composite gas reservoir, according to a preferred embodiment of the present invention.

[0040] Figure 9 This is a schematic diagram of the electronic device structure according to a preferred embodiment of the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0043] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of this application, including various details to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0044] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] It should be noted that the terminals involved in the embodiments of this application may include, but are not limited to, mobile phones, personal digital assistants (PDAs), wireless handheld devices, tablet computers, personal computers (PCs), MP3 players, MP4 players, wearable devices (e.g., smart glasses, smartwatches, smart bracelets), smart home devices, and other smart devices.

[0046] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0047] The present invention will now be described in further detail with reference to the accompanying drawings:

[0048] See Figure 1 This invention provides a trajectory design method for highly deviated wells in coal-sand composite gas reservoirs, comprising the following steps:

[0049] Step 1: Obtain information on drilled wells within the target area, predict reservoir planar distribution characteristics, and analyze geological adaptability.

[0050] Predicting the spatial distribution characteristics of reservoirs involves analyzing and summarizing data from drilled wells, and using geostatistical methods, such as variograms, kriging techniques, and stochastic simulation techniques, to make reasonable predictions of the spatial distribution of reservoir parameters and clarify the geological adaptability of high-angle wells for the co-development of sand and coal.

[0051] Step 1.1: Data preparation process.

[0052] Accurately grasp the information of drilled wells in the area where high-angle wells are implemented, and focus on collecting relevant parameters such as effective thickness, porosity, permeability and saturation of each gas-bearing stratum (including tight sandstone and coal rock) of the completed skeleton wells in the area. After sorting and analyzing the data, and combining it with the comparison of adjacent wells, use geostatistical methods, such as variogram, kriging and stochastic simulation techniques, to predict the planar distribution characteristics of reservoirs in the area.

[0053] Step 1.2: Geological adaptability analysis and evaluation.

[0054] By predicting the reservoir's planar distribution characteristics, the reservoir parameters of each gas-bearing section (including tight sandstone and coal) in the vertical direction are determined. The tight gas-bearing sandstone thickness is required to be ≥8m and the coal thickness to be ≥6m. The vertical depth of the gas-bearing section is 2200-2500m and the vertical thickness is >200m. At the same time, the co-production section is determined by combining the inter-layer difference coefficient calculated by the following formula to avoid inter-layer interference.

[0055]

[0056] Where i represents the stratigraphic segment, i = 1, 2, 3, ..., n, D i P represents the inter-layer difference coefficient. i K represents formation pressure. i This indicates the penetration rate.

[0057] Step 1.3: Determine the optimal trajectory design.

[0058] Based on the prediction of planar reservoir distribution, and combined with reservoir parameters (thickness, gas content) of different gas-bearing sections vertically, the relationship curves between formation plato-thickness and vertical thickness under different well inclinations and angles are designed, as shown in the figure. Figure 2 As shown, the trigonometric function method is used to calculate the inclination thickness of the gas-bearing stratum into the target, and the optimal well inclination of the target stratum is determined. Then, based on the vertical depth of the underlying gas-bearing stratum, the optimal well inclination of each gas-bearing stratum is determined in turn, and a well is designed to penetrate more than 300m in the coal and rock.

[0059] Step 2: Trajectory design and process parameter analysis.

[0060] Step 2.1: Logging design requirements.

[0061] Based on the drainage and production technology and the characteristics of coal and rock water production, jet pump drainage and gas production should be carried out. Considering the well depth characteristics of 2200-2500m vertical depth and >200m vertical thickness, the well inclination of the jet pump entry section should be <40°, and the trajectory smoothness should also be considered. Jet pump drainage and gas production technology should be used accordingly.

[0062] Step 2.2: Well depth structure design requirements.

[0063] Based on the formation characteristics, the drilling process clearly defines the deep surface second-stage wellbore structure and wellbore design parameters, and the wellbore trajectory design is as follows: Figure 3 As shown.

[0064] Step 2.3: Fracturing design requirements.

[0065] For highly deviated wells developed with overlapping coal and sandstone layers, the main fracturing process employs a phased fracturing and fusion approach. This involves fracturing 3-5 sections in the coal and sandstone section to achieve production, followed by fracturing 2-3 sections in the multi-layered sandstone section. The fracturing process places relatively low demands on well inclination design; a stepped trajectory design is sufficient for the fracturing process. Figure 4 As shown.

[0066] The present invention will be further described in detail below through specific embodiments:

[0067] Example 1:

[0068] Taking the Shuang 47-58X4 well, a highly deviated well used in the first collaborative development of coal-sand gas reservoirs in the Ordos Basin in 2023, as an example, this paper illustrates the stepped trajectory design method for highly deviated wells, which includes the following steps:

[0069] Step 1: Prediction of reservoir planar distribution characteristics and geological adaptability analysis.

[0070] Step 1.1: Data preparation process.

[0071] Detailed information on the drilled skeleton well Shuang 47-58 within the area where the Shuang 47-58X4 high-angle well was implemented was collected. Shuang 47-58 is located in the main sand belt of the area, with a 100% drilling rate of the gas-bearing layers in the He 8 to Benxi Formation. The average sandstone thickness is 58.4m, the gas layer thickness ranges from 12.4 to 28.7m, and the average effective reservoir thickness is 20.9m. The top elevation of the sand body in the He 8 target section of well Shuang 47-58 is -1064.0m, the bottom elevation of the Benxi Formation No. 8 coal seam is -1286.6m, the sand body thickness in the He 8 to Benxi Formation is 53.0m, the effective sand body thickness is 21.0m, the No. 5 coal seam thickness is 4.0m, and the No. 8 coal seam thickness is 10.5m. The predicted reservoir planar distribution characteristics within the He 8 to Benxi Formation No. 8 coal seam area of ​​well Shuang 47-58 are shown in Table 1.

[0072] Table 1. Prediction of parameters for coal reservoir No. 8 in the Hehe 8-Benxi Formation of Shuang 47-58 well.

[0073]

[0074] Step 1.2: Geological adaptability assessment.

[0075] Wells Shuang 47-58 have a tight gas-bearing sandstone thickness of ≥8m and a coal and rock thickness of ≥6m. The vertical depth of the gas-bearing strata is 2200-2500m and the vertical thickness is >200m. Considering the inter-stratum difference coefficient, the target strata, He 8 to Benxi Formation, are all low-pressure systems (formation pressure coefficient between 0.85 and 0.92) with a small inter-stratum difference coefficient (<0.1), making them suitable for multi-layer combined mining. In summary, they meet the geological requirements for implementing stepped high-angle wells.

[0076] Step 1.3: Evaluation of optimal trajectory design.

[0077] Based on the predicted planar reservoir distribution of wells 47-58, different target well inclinations (10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, 83°, 85°, 87°, 90°) were designed. The relationship between the marker layers of adjacent wells and the target guidance is as follows: Figure 5As shown, using the trigonometric function method and following the approach of "identifying the target layer, approaching layer by layer, and entering the target at a large angle in shallow layers," the well inclination of the gas-bearing strata in section 8 of the He-8 formation was calculated to be maintained at 35°, the top inclination of the Shanxi Formation Shan 23 was 70°, the top inclination of the inclined limestone was 75°, the bottom inclination of the gas-bearing sandstone in the Taiyuan Formation was 83°, and the top inclination of the No. 8 coal seam in the Benxi Formation was 87°. The well was completed after drilling 300 meters through the coal seam. The trajectory design is as follows: Figure 6 As shown.

[0078] Step 2: Trajectory design and process parameter analysis.

[0079] Step 2.1: Logging design requirements.

[0080] Based on the drainage and production technology and the characteristics of coal and rock water production, jet pump drainage and gas production are required. Considering the well depth characteristics of the He8-Benxi section of the Shuang 47-58 well (vertical depth 2210-2450m, vertical thickness greater than 200m), the well inclination requirement for the jet pump entry section is <40°. Simultaneously, considering a smooth trajectory, the design well inclination for the He8 section of the Shihezi group is approximately 35°. Jet pump drainage and gas production technology will be used in conjunction with this.

[0081] Step 2.2: Well depth structure design requirements.

[0082] Based on the geological characteristics, the drilling process clearly defines the wellbore structure and wellbore design parameters for the deep surface second section. The well inclination is 35° at the top of the gas layer in the He 8 section, 70° at the top of the No. 5 coal and rock in the Shan 23 section, 83° at the top of the gas layer in the Tai 22 section, and 87° at the top of the No. 8 coal and rock in the Benxi Formation, and gradually increases the inclination to 90° for 300 meters. The design target distance is 120m, and the length of the high-angle section is 846m.

[0083] Step 2.3: Fracturing design requirements.

[0084] For highly deviated wells with overlapping sand, coal, and rock formations, the main stimulation process adopts a combination of pressure and fracturing. For the Benxi Formation coal and rock section of the Shuang 47-58X4 well, a moderate-scale full-area support fracturing process is used to stimulate 4 sections and 8 clusters of coal and rock. It is planned to continue production for about 30 days according to the current production allocation to evaluate the reasonable production allocation of the coal seam.

[0085] The He 8 drilling encountered a gas-bearing layer of 22m. The proposed well section has an inclined thickness of 8.4m and a vertical thickness of 6.4m. The sonic transit time is 263.69μs / m, the natural gamma is 35.36API, the porosity is 13.84%, the permeability is 2.15mD, and the gas saturation is 56.35%. The overall evaluation is that it is a Class I reservoir.

[0086] Afterwards, two sections of the He 8 multi-layer sandstone were optimized and modified for production. The fracturing process does not have high requirements for well inclination design. The currently designed stepped trajectory can meet the requirements of the modification process. The actual drilling trajectory of the horizontal section is as follows: Figure 7 As shown.

[0087] This invention has an absolute advantage in the efficient development of coal-sand composite gas reservoirs, enabling the coordinated development of multiple resources and possessing significant economic and practical value.

[0088] Example 2:

[0089] Embodiment 2 provided by this invention is an embodiment of the trajectory design system for highly deviated wells in coal-sand composite gas reservoirs provided by this invention, such as... Figure 8 As shown, an embodiment of the system includes: an acquisition module, a trajectory module, and a design module.

[0090] The acquisition module is used to acquire drilling information within the target area, predict reservoir planar distribution characteristics, and analyze geological adaptability.

[0091] The trajectory module is used to determine the optimal trajectory of each gas-bearing stratum within the target area based on the reservoir's planar distribution characteristics and geological adaptability.

[0092] The design module is used to design the gas production process, drilling process and stimulation process of the highly deviated well based on the determined optimal trajectory, and to complete the trajectory design of the highly deviated well in the coal-sand composite gas reservoir.

[0093] It is understood that the trajectory design system for highly deviated wells in coal-sand composite gas reservoirs provided by this invention corresponds to the trajectory design method for highly deviated wells in coal-sand composite gas reservoirs provided in the foregoing embodiments. The relevant technical features of the trajectory design system for highly deviated wells in coal-sand composite gas reservoirs can be referred to the relevant technical features of the trajectory design method for highly deviated wells in coal-sand composite gas reservoirs, and will not be repeated here.

[0094] Another object of the present invention is to provide an electronic device, such as... Figure 9 As shown, it includes a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the steps of the trajectory design method for the highly deviated well in the coal-sand composite gas reservoir.

[0095] The trajectory design method for highly deviated wells in coal-sand composite gas reservoirs includes the following steps:

[0096] Obtain information on drilled wells within the target area, predict reservoir planar distribution characteristics, and analyze geological adaptability;

[0097] Based on the reservoir's planar distribution characteristics and geological adaptability, the optimal trajectory of each gas-bearing stratum within the target area is determined;

[0098] Based on the determined optimal trajectory, design the gas production technology, drilling technology and stimulation technology for highly deviated wells, and complete the trajectory design for highly deviated wells in coal-sand composite gas reservoirs.

[0099] The fourth objective of this invention is to provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of a trajectory design method for a highly deviated well in a coal-sand composite gas reservoir.

[0100] The trajectory design method for highly deviated wells in coal-sand composite gas reservoirs includes the following steps:

[0101] Obtain information on drilled wells within the target area, predict reservoir planar distribution characteristics, and analyze geological adaptability;

[0102] Based on the reservoir's planar distribution characteristics and geological adaptability, the optimal trajectory of each gas-bearing stratum within the target area is determined;

[0103] Based on the determined optimal trajectory, design the gas production technology, drilling technology and stimulation technology for highly deviated wells, and complete the trajectory design for highly deviated wells in coal-sand composite gas reservoirs.

[0104] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0105] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0106] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0107] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A trajectory design method for highly deviated wells in coal-sand composite gas reservoirs, characterized in that, include: Obtain information on drilled wells within the target area, predict reservoir planar distribution characteristics, and analyze geological adaptability; Based on the reservoir's planar distribution characteristics and geological adaptability, the optimal trajectory of each gas-bearing stratum within the target area is determined; Based on the determined optimal trajectory, design the gas production technology, drilling technology and stimulation technology for highly deviated wells, and complete the trajectory design for highly deviated wells in coal-sand composite gas reservoirs.

2. The trajectory design method for a highly deviated well in a coal-sand composite gas reservoir according to claim 1, characterized in that, The drilled well information includes the effective thickness, porosity, permeability, and saturation of each gas-bearing layer in the completed skeleton wells.

3. The trajectory design method for a highly deviated well in a coal-sand composite gas reservoir according to claim 1, characterized in that, The method for predicting the reservoir planar distribution characteristics is as follows: By organizing and analyzing the drilling information within the target area, and combining it with comparisons with adjacent wells, geostatistical methods are used, along with variograms, kriging techniques, and stochastic simulation techniques, to predict the planar distribution characteristics of reservoirs within the target area.

4. The trajectory design method for a highly deviated well in a coal-sand composite gas reservoir according to claim 1, characterized in that, The method for analyzing geological adaptability is as follows: Based on the prediction results of the reservoir planar distribution characteristics, the reservoir parameters of each gas-bearing section in the vertical direction are determined. Combined with the inter-layer difference coefficient, the co-production section is determined to avoid inter-layer interference. The reservoir parameters include tight gas-bearing sandstone ≥8m, coal and rock thickness ≥6m, gas-bearing section vertical depth of 2200~2500m and vertical thickness >200m.

5. The trajectory design method for a highly deviated well in a coal-sand composite gas reservoir according to claim 4, characterized in that, The interlayer difference coefficient is: Where i represents the stratigraphic segment, i = 1, 2, 3, ..., n, D i P represents the inter-layer difference coefficient. i K represents formation pressure. i This indicates the penetration rate.

6. The trajectory design method for a highly deviated well in a coal-sand composite gas reservoir according to claim 1, characterized in that, The process for determining the optimal trajectory for each gas-bearing stratum within the target area is as follows: Based on the predicted reservoir planar distribution characteristics and combined with the reservoir parameters of each gas-bearing section in the vertical direction, different well inclinations for target entry are designed. The inclination thickness of the gas-bearing section for target entry is calculated using the trigonometric function method to determine the optimal well inclination for the target entry section. Then, based on the vertical depth of the underlying gas-bearing section, the optimal well inclination for each gas-bearing section is determined in turn.

7. The trajectory design method for a highly deviated well in a coal-sand composite gas reservoir according to claim 1, characterized in that, The modification process is a combination of pressure and extraction, which modifies 3 to 5 sections of coal and rock sections to increase production, and modifies 2 to 3 sections of multi-layered sandstone sections to increase production.

8. A trajectory design system for highly deviated wells in coal-sand composite gas reservoirs, characterized in that, include: The acquisition module is used to acquire drilling information within the target area, predict reservoir planar distribution characteristics, and analyze geological adaptability. The trajectory module is used to determine the optimal trajectory of each gas-bearing stratum within the target area based on the reservoir's planar distribution characteristics and geological adaptability. The design module is used to design the gas production process, drilling process and stimulation process of the highly deviated well based on the determined optimal trajectory, and to complete the trajectory design of the highly deviated well in the coal-sand composite gas reservoir.

9. A terminal 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, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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