A method and related device for adjusting a well pattern in oil and gas field development

Abstract

The application discloses an oil and gas field development well pattern adjustment method and related equipment, and the method comprises the following steps: calculating the effect degree of a well group and performing single sand body description processing; adjusting the well pattern according to the single sand body after the description processing; and simulating the numerical value of the adjusted well pattern. Through the collection of oil reservoir data in the early stage, the single sand body description is performed by using the collected oil reservoir data, the contact type of the described single sand body is regressed and verified, and a separate injection-production system can be formed in the isolated single sand body of the vertically developed oil reservoir, so that the water drive efficiency of the oil reservoir is improved.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field development technology, specifically relating to a method for adjusting well patterns in oil and gas field development and related equipment. Background Technology

[0002] The ultra-low to ultra-low permeability reservoirs of Changqing Oilfield play a crucial role in maintaining stable production. However, in the early stages of development, the reservoirs were not fully understood. As the main reservoirs entered the medium-to-high water-cut stage, the challenges of oilfield development became increasingly apparent. The water drive situation became complex in both planar and profile dimensions, the adaptability of the primary well network deteriorated, and conventional injection-production control methods proved ineffective. Since 2010, pilot infill drilling and adjustment tests have been conducted in some reservoirs and gradually expanded to the main reservoirs. In Ansai Oilfield, after infill drilling, the water drive reserve control level increased by 6.8%, and the recovery rate increased by 4%, demonstrating the application potential and feasibility of infill drilling and adjustment technology.

[0003] Currently, the basic well network of Changqing Oilfield mainly includes three types: square inverted nine-point, rhomboid inverted nine-point, and rectangular well networks. Based on different primary well networks and water drive characteristics, through years of research and practice infiltration and adjustment, three mature well network infiltration and adjustment models have been formed: for pore seepage, reducing well spacing and using inverted nine-point well networks; for unidirectional fracture seepage, reducing well spacing and using row-shaped or rectangular well networks; and for reservoirs with water breakthrough in multiple directions, adjusting to irregular well networks. However, current well network adjustments only consider planar well network combinations, neglecting the effective utilization of isolated sand bodies in the vertical direction, and the reserves of individual sand bodies cannot be effectively utilized.

[0004] The single sand body characterization coverage rate in Changqing Oilfield has reached 92.4%. Detailed characterization of the vertical and planar contact patterns of the single sand bodies is carried out to describe the profile and planar distribution characteristics. Based on the single sand body characterization results, some reservoirs with vertically developed small layers have been found, and lenticular sand bodies exist in some areas. The single sand bodies do not have corresponding water injection, so they cannot form water injection displacement, which affects the development effect. There is an urgent need for a well pattern adjustment method to improve the reserve utilization of such single sand bodies. Summary of the Invention

[0005] The purpose of this invention is to solve the problems in the prior art and to provide a method and related equipment for adjusting the well network in oil and gas field development.

[0006] According to a first aspect of the present invention, a method for adjusting the well pattern in oil and gas field development is provided, comprising:

[0007] Calculate the effectiveness of the well group and perform individual sand body characterization;

[0008] The well pattern is adjusted based on the individual sand bodies after the characterization process.

[0009] The adjusted well network values ​​were simulated.

[0010] Furthermore, the effectiveness of the well group is calculated and individual sand body characterization is performed, specifically including:

[0011] First, collect dynamic and static reservoir data. The dynamic data includes dynamic data and dynamic monitoring data, and the static data includes layer data and well logging data.

[0012] The effectiveness of the well group is calculated based on the dynamic data. The single sand body is characterized based on the logging data and the layer data. The width-to-thickness ratio of the single sand body is calculated based on the single sand body characterization results.

[0013] Furthermore, the single sand body characterization process is performed based on well logging data and layer data, specifically as follows:

[0014] According to the single sand body depiction standard, the contact types are divided into longitudinal and transverse types; among them, the longitudinal type is divided into isolated type, superimposed type and cut-overlap type, and the transverse type is divided into separated type, butt joint type and side cut type.

[0015] Furthermore, the classification of contact types based on longitudinal and transverse directions specifically includes:

[0016] Using well test data, dynamic verification and dynamic monitoring data, the boundaries of individual sand bodies are identified, the connectivity between oil and water wells is finely characterized, and the contact type of individual sand bodies is further verified.

[0017] Among them, the sand body boundary is determined by using well test data: pressure monitoring data is obtained by opening pressure drop and shut-in pressure recovery, well test curves are plotted and flow stages are divided, the characteristics of the boundary flow stage curves are judged based on well test software diagnostic tools, and the corresponding boundary models are selected in combination with different characteristics. At the same time, the nonlinear seepage equation of low-permeability reservoirs is considered. After model fitting, the distance parameter Li from the well to the closed boundary is obtained and compared with the well spacing to determine the sand body connectivity.

[0018] The sand body boundary was determined by dynamic verification: the sand body connectivity was judged by the excitation response formed by the opening and closing of oil and water wells.

[0019] The sand body boundary was determined using dynamic monitoring data. The sweep range and sweep width of the water drive were determined using water drive front testing and tracer testing to verify the sand body connectivity.

[0020] Furthermore, after calculating the effectiveness of the well group and performing single sand body characterization, the method also includes applying a random forest regression algorithm to perform regression processing on the calculated effectiveness of the well group, the stacking relationship of single sand bodies, and the width-to-thickness ratio of single sand bodies to obtain the classification boundary of single sand body contact relationship.

[0021] Furthermore, the classification boundaries of the contact relationships of the single sand bodies include:

[0022] When the width-to-thickness ratio of a single sand body is less than 40, it is an isolated type; when the width-to-thickness ratio of a single sand body is less than 40 and less than 60, it is a superimposed type; when the width-to-thickness ratio of a single sand body is greater than 60, it is a cut-and-stack type.

[0023] Furthermore, the adjustment of the well pattern based on the single sand body after the characterization process specifically includes:

[0024] Based on the completed single sand body distribution and single sand body contact type, the well pattern adjustment is completed by using the same well injection and production method. When the width-to-thickness ratio of a single sand body is greater than 60, that is, the contact type is stacked, and a complete injection and production system is available, conventional injection and production well pattern is used for development.

[0025] When the width-to-thickness ratio of a single sand body is less than 40, that is, the contact type is isolated, there are local situations where injection and production do not correspond, including injection without production and production without injection. The same well injection and production method is adopted, that is, the same well uses the oil casing separation technology to produce oil and inject water on different single sand bodies. Vertically, different single sand bodies form separate injection and production systems to improve water drive efficiency.

[0026] According to a second aspect of the present invention, an oil and gas field development well pattern adjustment system is provided, comprising:

[0027] Data acquisition module: used to acquire reservoir data;

[0028] Data processing module: The acquired reservoir data is used to process the well group effectiveness and the characterization of individual sand bodies.

[0029] Data simulation module: used to simulate the processed data.

[0030] According to a third aspect of the present invention, an electronic device is provided, including a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement the steps of the oil and gas field development well pattern adjustment method as described above.

[0031] According to a fourth aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the oil and gas field development well pattern adjustment method as described above.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The well pattern adjustment method based on single sand body characterization provided by the present invention collects reservoir data in the early stage, uses the collected reservoir data to characterize single sand bodies, and regresses and verifies the contact type of the characterized single sand bodies. This can realize the formation of a separate injection and production system in isolated single sand bodies of reservoirs with vertically developed small layers, thereby improving the reservoir water drive efficiency.

[0034] 2. Optimize and adjust the well network by applying the "same well injection and production" method. That is, the same well uses the method of separating the oil casing and the casing, so that different single sand bodies can both produce oil and inject water, so that different single sand bodies in the vertical direction form a separate injection and production system, thereby improving water drive efficiency. Attached Figure Description

[0035] 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.

[0036] Figure 1 Logic diagram of the oil and gas field development well pattern adjustment method provided by the present invention;

[0037] Figure 2 This is a schematic diagram of the single sand body characterization and densification adjustment in the oil and gas field development well network adjustment method provided by the present invention;

[0038] Figure 3 This invention provides a well location diagram for a diamond-shaped inverted nine-point well network in the oil and gas field development well network adjustment method.

[0039] Figure 4 This invention provides a method for adjusting the well network in oil and gas field development, including a sand body profile of the well group.

[0040] Figure 5 Plan view of single sand bodies No. 2 and No. 3 in the oil and gas field development well pattern adjustment method provided by the present invention:

[0041] Figure 6 This is a schematic diagram of the well pattern adjustment scheme design in the oil and gas field development well pattern adjustment method provided by the present invention;

[0042] Figure 7 A schematic diagram of a three-dimensional model of a rhomboid inverted nine-point well network injection and production system in the oil and gas field development well network adjustment method provided by the present invention;

[0043] Figure 8 Curves showing the relationship between water cut and recovery rate under different schemes in the oil and gas field development well pattern adjustment method provided by the present invention;

[0044] Figure 9 A bar chart showing the final recovery rate of different schemes in the oil and gas field development well pattern adjustment method provided by the present invention;

[0045] Figure 10 A block diagram of the oil and gas field development well network adjustment system provided by the present invention. Detailed Implementation

[0046] 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.

[0047] 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.

[0048] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0049] The present invention will now be described in further detail with reference to the accompanying drawings:

[0050] This invention provides a method and related equipment for adjusting the well pattern in oil and gas field development. According to a first aspect of this invention, a method for adjusting the well pattern in oil and gas field development is provided, such as... Figure 1 As shown, it includes the following steps:

[0051] Step 1: Calculate the effectiveness of the well group and perform single sand body characterization; specifically, this includes: first, collecting reservoir dynamic and static data, including dynamic data and dynamic monitoring data, and static data including layer data and logging data; calculating the effectiveness of the well group based on the dynamic data, performing single sand body characterization based on the logging data and layer data, and calculating the width-to-thickness ratio of the single sand body based on the single sand body characterization results; specifically, the single sand body characterization based on the logging data and layer data involves: classifying contact types vertically and horizontally according to the single sand body characterization standard; vertically, it is divided into isolated, superimposed, and cut-overlapping types, and horizontally, it is divided into separated, butt joint, and side-cut types; further, classifying contact types vertically and horizontally involves: using well test data, dynamic verification, and dynamic monitoring data to determine the boundaries of single sand bodies, finely characterizing the connectivity between oil and water wells, and further verifying the single sand body contact types;

[0052] Among them, the sand body boundary is determined by using well test data: pressure monitoring data is obtained by opening pressure drop and shut-in pressure recovery, well test curves are plotted and flow stages are divided, the characteristics of the boundary flow stage curves are judged based on well test software diagnostic tools, and the corresponding boundary models are selected in combination with different characteristics. At the same time, the nonlinear seepage equation of low-permeability reservoirs is considered. After model fitting, the distance parameter Li from the well to the closed boundary is obtained and compared with the well spacing to determine the sand body connectivity.

[0053] The sand body boundary was determined by dynamic verification: the sand body connectivity was judged by the excitation response formed by the opening and closing of oil and water wells.

[0054] The sand body boundary was determined using dynamic monitoring data. The sweep range and sweep width of the water drive were determined using water drive front testing and tracer testing to verify the sand body connectivity.

[0055] Furthermore, after calculating the width-to-thickness ratio of a single sand body, the random forest regression algorithm is applied to perform regression processing on the calculated well group effectiveness, single sand body stacking relationship, and single sand body width-to-thickness ratio to obtain the classification boundary of single sand body contact relationship. The classification boundary includes: when the single sand body width-to-thickness ratio is <40, it is isolated; when 40 < single sand body width-to-thickness ratio <60, it is superimposed; and when the single sand body width-to-thickness ratio is >60, it is cut-and-stacked.

[0056] Step 2: Adjust the well pattern according to the single sand body after the characterization process. Specifically, the well pattern is adjusted by applying the same injection and production method based on the distribution and contact type of the single sand body after characterization. When the width-to-thickness ratio of the single sand body is greater than 60, that is, the contact type is cut-and-stack, and a complete injection and production system is available, conventional injection and production well pattern is used for development.

[0057] When the width-to-thickness ratio of a single sand body is less than 40, that is, the contact type is isolated, there are local situations where injection and production do not correspond, including injection without production and production without injection. The same well injection and production method is adopted, that is, the same well uses the oil casing separation technology to produce oil and inject water on different single sand bodies. Vertically, different single sand bodies form separate injection and production systems to improve water drive efficiency.

[0058] Step 3: Simulate the adjusted well network values; for the same injection-production method designed in Step 2, design different injection-production schemes for numerical simulation and prediction, establish a numerical simulation model, predict the schemes, and select the development scheme with the highest recovery rate; such as Figure 3 As shown, taking a commonly used rhomboid inverted nine-point well pattern as an example, it is vertically subdivided into three small layers for development. After characterizing the single sand bodies, it is considered that single sand bodies No. 2 and No. 3 are isolated single sand bodies. If developed with a single well pattern, single sand bodies No. 2 and No. 3 have no corresponding water injection and cannot form water injection displacement, affecting the development effect. Based on the sand body distribution, different schemes are designed and scheme prediction is carried out. Finally, the scheme with the highest recovery rate is selected for development, such as... Figure 2 As shown.

[0059] When a water injection development reservoir A is selected, a same-well injection-production scheme is designed according to this method, and numerical simulation is performed. The optimal implementation scheme is selected, and a reservoir numerical model is established based on the basic geological parameters of the Triassic reservoir, such as... Figure 4 and Figure 5 As shown, the reservoir is divided into three sub-layers (sand layers with thicknesses of 5m, 4m, and 5m respectively, and a 2m interlayer thickness). The top and bottom layers are continuous single sand bodies, while the middle layers, sand bodies No. 2 and No. 3, are isolated single sand bodies. Wells No. 1, 2, and 3 control sand body No. 2, and wells No. 6 and 7 control sand body No. 3. Figure 3 As shown, the well pattern design is a 480m×150m rhomboid inverted nine-point well pattern.

[0060] Based on the contact relationship, the design scheme addresses the issue of isolated single sand bodies. If conventional injection-production well networks are used, the single sand body lacks corresponding water injection, failing to achieve water displacement and impacting development efficiency. The "same-well injection-production" approach optimizes the well network, where the same well utilizes a casing separation method to allow different single sand bodies to both produce oil and inject water. This creates separate injection-production systems for different single sand bodies vertically, improving water drive efficiency.

[0061] like Figure 6 and Figure 7 As shown, six schemes were developed overall. The original scheme was a conventional injection-production well pattern, with oil production at points A and E. Scheme 1: Water injection at point B, oil production at points A and C; oil production at point D, water injection at point E. Scheme 2: Water injection at point B, oil production at points A and C; oil production at point E, water injection at point D. Scheme 3: Water injection at point A, oil production at points B and C; oil production at point D, water injection at point E. Scheme 4: Water injection at point A, oil production at points B and C; oil production at point E, water injection at point D. Scheme 5: Water injection at point C, oil production at points A and B; oil production at point D, water injection at point E. Scheme 6: Water injection at point C, oil production at points A and B; oil production at point E, water injection at point D.

[0062] like Figure 8 and Figure 9 As shown, numerical simulation was used to predict the recovery scheme. The simulation results show that the "same-well injection and production" method effectively utilizes the remaining oil in a single sand body, achieving a higher recovery rate than the "conventional water injection" method. Scheme 1 (water injection at points B and E) can increase the recovery rate by 2.49% compared to the original scheme, making it the optimal scheme.

[0063] According to a second aspect of the present invention, an oil and gas field development well pattern adjustment system is provided, comprising:

[0064] Data acquisition module: used to acquire reservoir data;

[0065] Data processing module: The acquired reservoir data is used to process the well group effectiveness and the characterization of individual sand bodies.

[0066] Data simulation module: used to simulate the processed data.

[0067] According to a third aspect of the present invention, an electronic device is provided, including a memory and a processor, the memory storing a computer program, the processor executing the computer program to implement the steps of the oil and gas field development well pattern adjustment method as described above.

[0068] According to a fourth aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the oil and gas field development well pattern adjustment method as described above.

[0069] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory may include random access memory (RAM) or external cache memory.

[0070] By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0071] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for adjusting the well pattern in oil and gas field development, characterized in that, include: Calculate the effectiveness of the well group and perform individual sand body characterization; The well pattern is adjusted based on the individual sand bodies after the characterization process. The adjusted well network values ​​were simulated; Random forest regression algorithm was applied to regress the calculated well group effectiveness, single sand body stacking relationship and single sand body width-to-thickness ratio to obtain the classification boundary of single sand body contact relationship; The classification boundaries for contact relationships of individual sand bodies include: When the width-to-thickness ratio of a single sand body is less than 40, it is an isolated type; when the width-to-thickness ratio of a single sand body is less than 40 and less than 60, it is a superimposed type; when the width-to-thickness ratio of a single sand body is greater than 60, it is a cut-and-stack type. Based on the completed single sand body distribution and single sand body contact type, the well pattern adjustment is completed by using the same well injection and production method. When the width-to-thickness ratio of a single sand body is greater than 60, that is, the contact type is stacked, and a complete injection and production system is available, conventional injection and production well pattern is used for development. When the width-to-thickness ratio of a single sand body is less than 40, that is, the contact type is isolated, there are local situations where injection and production do not correspond, including injection without production and production without injection. The same well injection and production method is adopted, that is, the same well uses the oil casing separation technology to produce oil and inject water on different single sand bodies. Vertically, different single sand bodies form separate injection and production systems to improve water drive efficiency.

2. The method for adjusting the well pattern in oil and gas field development according to claim 1, characterized in that, The effectiveness of the well group was calculated and individual sand body characterization was performed, specifically including: First, collect dynamic and static reservoir data. The dynamic data includes dynamic data and dynamic monitoring data, and the static data includes layer data and well logging data. The effectiveness of the well group is calculated based on the dynamic data, the single sand body is characterized based on the logging data and the layer data, and the width-to-thickness ratio of the single sand body is calculated based on the single sand body characterization results.

3. The method for adjusting the well pattern in oil and gas field development according to claim 2, characterized in that, The single sand body characterization process is performed based on well logging data and layer data, specifically as follows: According to the single sand body depiction standard, the contact types are divided into longitudinal and transverse types; among them, the longitudinal type is divided into isolated, superimposed and cut-overlapping, and the transverse type is divided into separated, butt joint and side-cutting.

4. The method for adjusting the well pattern in oil and gas field development according to claim 3, characterized in that, The classification of contact types based on longitudinal and transverse directions specifically includes: Using well test data, dynamic verification and dynamic monitoring data, the boundaries of individual sand bodies are identified, the connectivity between oil and water wells is finely characterized, and the contact type of individual sand bodies is further verified. Among them, the sand body boundary is determined by using well test data: pressure monitoring data is obtained by opening pressure drop and shut-in pressure recovery, well test curves are plotted and flow stages are divided, the characteristics of the boundary flow stage curves are judged based on well test software diagnostic tools, and the corresponding boundary models are selected in combination with different characteristics. At the same time, the nonlinear seepage equation of low-permeability reservoirs is considered. After model fitting, the distance parameter Li from the well to the closed boundary is obtained and compared with the well spacing to determine the sand body connectivity. The sand body boundary was determined by dynamic verification: the sand body connectivity was judged by the excitation response formed by the opening and closing of oil and water wells. The sand body boundary was determined using dynamic monitoring data. The sweep range and sweep width of the water drive were determined using water drive front testing and tracer testing to verify the sand body connectivity.

5. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the oil and gas field development well network adjustment method according to any one of claims 1-4.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the oil and gas field development well network adjustment method according to any one of claims 1-4.

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