Oil and gas field development well pattern adjusting method and related equipment

Abstract

The invention discloses an oil and gas field development well pattern adjusting method and related equipment. The method comprises the steps that the effectiveness degree of a well group is calculated, and single sand body depicting treatment is conducted; the well pattern is adjusted according to the depicted single sand body; and simulating the adjusted numerical value of the well pattern. By collecting oil reservoir data in the early stage, utilizing the collected oil reservoir data to carry out single sand body depiction, returning the depicted single sand body and verifying the contact type, an independent injection-production system can be formed in the isolated single sand body of the longitudinal small-layer development oil reservoir, and the water drive efficiency of the oil reservoir is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas field development, and in particular relates to an oil and gas field development well pattern adjustment method and related equipment. Background Art

[0002] The ultra-low-ultra-low permeability reservoirs in Changqing Oilfield play a ballast role in stabilizing production. In the early stage of development, the reservoirs were not fully understood. As the main reservoirs entered the medium-high water content stage, the contradictions in oilfield development became increasingly prominent. The plane and profile water drive conditions were complex, the adaptability of the primary well network became poor, and the conventional injection and production control effect was not ideal. Since 2010, pilot tests of infill adjustment have been carried out in some reservoirs and gradually expanded to the main reservoirs. After infilling, the water drive reserve control degree of Ansai Oilfield increased by 6.8%, and the recovery rate increased by 4%, showing the application potential and feasibility of infill adjustment technology.

[0003] At present, the basic well pattern of Changqing Oilfield mainly includes three types: square inverted nine-point, diamond inverted nine-point and rectangular well patterns. According to different primary well patterns and water drive characteristics, through years of intensification adjustment research and practice, three mature well pattern intensification adjustment modes have been formed, namely, pore seepage, reducing well row spacing, inverted nine-point well pattern; unidirectional fracture seepage, reducing row spacing, row well pattern or rectangular well pattern; multi-directional water reservoir, adjusted to irregular well pattern. However, the current well pattern adjustment only considers the combination of plane well patterns, ignoring the effective use of isolated sand bodies in the vertical direction, and the reserves of single sand bodies cannot be effectively used.

[0004] The current single sand body characterization coverage rate of Changqing Oilfield has reached 92.4%. The vertical and planar contact modes of the single sand bodies were characterized in detail, and the profile and planar distribution characteristics were finally described. According to the results of single sand body characterization, it was found that some oil reservoirs with developed vertical small layers had lens sand bodies locally. The single sand bodies had no corresponding water injection and could not form water injection displacement, which affected the development effect. A well network adjustment method was urgently needed to improve the reserve utilization of such single sand bodies. Summary of the invention

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

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

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

[0008] adjusting the well pattern according to the single sand body after the characterization process;

[0009] The adjusted values ​​of the well pattern are simulated.

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

[0011] First, dynamic and static data of the oil reservoir are collected, wherein the dynamic data includes dynamic data and dynamic monitoring data, and the static data includes small layer data and well logging data;

[0012] The effectiveness of the well group is calculated according to the dynamic data, the single sand body characterization process is performed according to the logging data and the small layer data, and the single sand body width-to-thickness ratio is calculated according to the single sand body characterization process result.

[0013] Further, the single sand body characterization process is performed according to the well logging data and the small layer data, specifically:

[0014] According to the single sand body characterization standard, the contact types are divided vertically and horizontally; among them, the vertical types are isolated, superimposed and cut-overlapping, and the horizontal types are separated, butt-jointed and side-cut.

[0015] Furthermore, the contact types are divided vertically and horizontally, specifically including:

[0016] Using well test data, dynamic verification and dynamic monitoring data, we can identify the boundaries of single sand bodies, finely characterize the connectivity between oil and water wells, and further verify the contact type of single sand bodies;

[0017] Among them, the sand body boundary is determined by using well test data: the pressure monitoring data is obtained through the pressure drop of opening wells and the pressure recovery of closing wells, the well test curve is drawn and the flow stage is divided, the characteristics of the boundary flow stage curve are judged based on the well test software diagnostic tool, and the corresponding boundary model is selected based on different characteristics. At the same time, the nonlinear seepage equation of low permeability reservoirs is considered. After the model is fitted, the distance parameter Li from the well to the closed boundary is compared with the well spacing to determine the connectivity of the sand body;

[0018] The sand body boundary is determined by dynamic verification: the connectivity of the sand body is determined by the exciting response formed by the closing and opening of oil and water wells;

[0019] The dynamic monitoring data are used to determine the boundaries of the sand body: the water flooding front test and tracer test are used to determine the water flooding range, sweep width, etc., and verify the connectivity of the sand body.

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

[0021] Furthermore, the classification boundaries of the single sand body contact relationship include:

[0022] When the single sand body width-to-thickness ratio is <40, it is isolated type; when the single sand body width-to-thickness ratio is 40<single sand body width-to-thickness ratio is <60, it is superimposed type; when the single sand body width-to-thickness ratio is >60, it is cut-and-stacked type.

[0023] Furthermore, the adjusting the well pattern according to the single sand body after the characterization process specifically includes:

[0024] According to the distribution of single sand bodies and the contact type of single sand bodies, the well pattern adjustment is completed by 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 a cut-and-stack type, it has a complete injection and production system and is developed using a conventional injection and production well pattern.

[0025] When the width-to-thickness ratio of a single sand body is less than 40, that is, the contact type is isolated, there is a mismatch between injection and production in some parts, including injection without production and production without injection. The same-well injection-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. Different single sand bodies in the vertical direction form separate injection-production systems to improve water drive efficiency.

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

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

[0028] Data processing module: using the obtained reservoir data to perform data processing on the effectiveness of the well group and the characterization of the single sand body;

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

[0030] According to a third aspect of the present invention, there is provided an electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method for adjusting the well pattern of oil and gas field development as described above when executing the computer program.

[0031] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps of the method for adjusting the well pattern of oil and gas field development are implemented 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 the single sand body, regresses the characterized single sand body and verifies the contact type, so as to form a separate injection-production system in the isolated single sand body of the vertically small-layer developed reservoir, thereby improving the water drive efficiency of the reservoir.

[0034] 2. Apply the "same-well injection and production" method to optimize and adjust the well network, that is, the same well uses the oil-casing separation method to produce oil and inject water in different single sand bodies, so that different single sand bodies in the vertical direction form separate injection and production systems, thereby improving water drive efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

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

[0037] Figure 2 A schematic diagram of single sand body characterization and intensification adjustment in the oil and gas field development well pattern adjustment method provided by the present invention;

[0038] Figure 3 A well location map of a diamond inverted nine-point well pattern in the oil and gas field development well pattern adjustment method provided by the present invention;

[0039] Figure 4 A cross-sectional view of a sand body of a well group in the oil and gas field development well pattern adjustment method provided by the present invention;

[0040] Figure 5 The 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 A schematic diagram of a 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 injection and production model of a diamond-shaped inverted nine-point well pattern in the oil and gas field development well pattern adjustment method provided by the present invention;

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

[0044] Fig. 9 A bar graph of final recovery rates of different solutions in the oil and gas field development well pattern adjustment method provided by the present invention;

[0045] Fig.10 This is a block diagram of the oil and gas field development well pattern adjustment system provided by the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0047] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.

[0048] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0049] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0050] The embodiment of the present invention provides a method for adjusting the well pattern of oil and gas field development and related equipment. According to a first aspect of the present invention, a method for adjusting the well pattern of oil and gas field development is provided. Figure 1 As shown, the following steps are included:

[0051] Step 1: Calculate the effectiveness of the well group and perform single sand body characterization processing; specifically include: first collect dynamic and static data of the reservoir, the dynamic data include dynamic data and dynamic monitoring data, and the static data include small layer data and logging data; calculate the effectiveness of the well group according to the dynamic data, perform single sand body characterization processing according to the logging data and small layer data, and calculate the single sand body width-to-thickness ratio according to the single sand body characterization processing result; wherein, the single sand body characterization processing is performed according to the logging data and small layer data, specifically: according to the single sand body characterization standard, the contact type is divided vertically and horizontally; wherein, the vertical type is divided into isolated type, superposition type and cut-over type, and the horizontal type is divided into separation type, docking type and side-cut type; and the vertical and horizontal types of contact types are divided specifically include: using well test data, dynamic verification and dynamic monitoring data to determine the boundary of a single sand body, finely characterize the connectivity between oil and water wells, and further verify the single sand body contact type;

[0052] Among them, the sand body boundary is determined by using well test data: the pressure monitoring data is obtained through the pressure drop of opening wells and the pressure recovery of closing wells, the well test curve is drawn and the flow stage is divided, the characteristics of the boundary flow stage curve are judged based on the well test software diagnostic tool, and the corresponding boundary model is selected based on different characteristics. At the same time, the nonlinear seepage equation of low permeability reservoirs is considered. After the model is fitted, the distance parameter Li from the well to the closed boundary is compared with the well spacing to determine the connectivity of the sand body;

[0053] The sand body boundary is determined by dynamic verification: the connectivity of the sand body is determined by the exciting response formed by the closing and opening of oil and water wells;

[0054] The dynamic monitoring data are used to determine the boundaries of the sand body: the water flooding front test and tracer test are used to determine the water flooding range, sweep width, etc., and verify the connectivity of the sand body.

[0055] Furthermore, after calculating the single sand body width-to-thickness ratio, the random forest regression algorithm is also used to regress the calculated well group effectiveness, single sand body superposition relationship and single sand body width-to-thickness ratio to obtain the classification boundaries of the single sand body contact relationship. The classification boundaries include: 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; when the single sand body width-to-thickness ratio is >60, it is cut and stacked.

[0056] Step 2: adjusting the well pattern according to the single sand body after characterization, specifically including: according to the distribution of the single sand body and the contact type of the single sand body after characterization, the well pattern is adjusted by the same-well injection and production method; when the width-to-thickness ratio of the single sand body is greater than 60, that is, the contact type is a cut-and-stack type, a complete injection and production system is provided, and conventional injection and production well patterns are 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 is a mismatch between injection and production in some parts, including injection without production and production without injection. The same-well injection-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. Different single sand bodies in the vertical direction form separate injection-production systems to improve water drive efficiency.

[0058] Step 3: Simulate the values ​​of the adjusted well pattern; design different injection and production schemes for numerical simulation prediction according to the same well injection and production mode designed in step 2, establish a numerical simulation model, perform scheme prediction, and select the development scheme with the highest recovery rate; Figure 3 As shown in the figure, taking the commonly used diamond inverted nine-point well pattern as an example, it is subdivided into three small layers for development vertically. After the single sand body is characterized, it is considered that the No. 2 and No. 3 single sand bodies are isolated single sand bodies. If a set of well patterns are used for development, the No. 2 and No. 3 single sand bodies have no corresponding water injection and cannot form water injection displacement, which affects the development effect. According to the distribution of sand bodies, different schemes are designed for scheme prediction, and finally the scheme with the highest recovery rate is selected for development, such as Figure 2 shown.

[0059] When a water injection development reservoir A is selected, a same-well injection and production scheme is designed according to this method, and numerical simulation is carried out. The best implementation scheme is selected, and a reservoir numerical model is established according to the basic geological parameters of the Triassic reservoir, such as Figure 4 and Figure 5 As shown in the figure, the reservoir is divided into three small layers (the thickness of the sand layers is 5m, 4m, and 5m respectively, and the thickness of the small layer interval is 2m). The top and bottom single sand bodies are continuous, and the middle layer No. 2 and No. 3 sand bodies are isolated single sand bodies. The No. 1, 2, and 3 oil production wells control the No. 2 single sand body, and the No. 6 and 7 oil production wells control the No. 3 single sand body. Figure 3 As shown in the figure, the development well pattern is designed as a 480m×150m diamond-shaped inverted nine-point well pattern.

[0060] According to the contact relationship, the scheme is designed. For isolated single sand bodies, if conventional injection-production well network is used for development, the single sand body has no corresponding water injection, and water injection displacement cannot be formed, which affects the development effect. The "same well injection-production" method is used to optimize and adjust the well network, that is, the same well uses the oil-casing separation method, and different single sand bodies are both produced and injected with water, so that different single sand bodies in the vertical direction form separate injection-production systems to improve water drive efficiency.

[0061] like Figure 6 and Figure 7 As shown in the figure, six schemes are formed in total. The original scheme is a conventional injection and production well network, with oil production at points A and E. Scheme 1 is water injection at point B, oil production at points A and C; oil production at point D, and water injection at point E. Scheme 2 is water injection at point B, oil production at points A and C; oil production at point E, and water injection at point D. Scheme 3 is water injection at point A, oil production at points B and C; oil production at point D, and water injection at point E. Scheme 4 is water injection at point A, oil production at points B and C; oil production at point E, and water injection at point D. Scheme 5 is water injection at point C, oil production at points A and B; oil production at point D, and water injection at point E. Scheme 6 is water injection at point C, oil production at points A and B; oil production at point E, and water injection at point D.

[0062] like Figure 8 and Fig. 9 As shown in the figure, numerical simulation methods are used to predict the scheme. From the numerical simulation results, it can be seen that the remaining oil in a single sand body is effectively utilized by the "same well injection and production" method, and the recovery rate is higher than that of the "conventional water injection" method. Scheme 1 can increase the recovery rate by 2.49% on the basis of the original scheme, and is the optimal scheme (water injection at points B and E).

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

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

[0065] Data processing module: using the obtained reservoir data to perform data processing on the effectiveness of the well group and the characterization of the single sand body;

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

[0067] According to a third aspect of the present invention, there is provided an electronic device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method for adjusting the well pattern of oil and gas field development as described above when executing the computer program.

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

[0069] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may 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 may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0071] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for adjusting a well pattern in oil and gas field development, characterized in that: include: Calculate the effectiveness of the well group and perform single sand body characterization processing; adjusting the well pattern according to the single sand body after the characterization process; The adjusted values ​​of the well pattern are simulated.

2. The method for adjusting the well pattern of oil and gas field development according to claim 1, characterized in that: Calculate the effectiveness of the well group and perform single sand body characterization, including: First, dynamic and static data of the oil reservoir are collected, wherein the dynamic data includes dynamic data and dynamic monitoring data, and the static data includes small layer data and well logging data; The effectiveness of the well group is calculated according to the dynamic data, the single sand body characterization process is performed according to the logging data and the small layer data, and the single sand body width-to-thickness ratio is calculated according to the single sand body characterization process result.

3. The method for adjusting the well pattern of oil and gas field development according to claim 2, characterized in that: The single sand body characterization process is performed according to the well logging data and the small layer data, specifically: According to the single sand body characterization standard, the contact types are divided vertically and horizontally; among them, the vertical types are isolated, superimposed and cut-overlapping, and the horizontal types are separated, butt-jointed and side-cut.

4. The method for adjusting the well pattern of oil and gas field development according to claim 3, characterized in that: The contact types are divided vertically and horizontally, specifically including: Using well test data, dynamic verification and dynamic monitoring data, we can identify the boundaries of single sand bodies, finely characterize the connectivity between oil and water wells, and further verify the contact type of single sand bodies; Among them, the sand body boundary is determined by using well test data: the pressure monitoring data is obtained through the pressure drop of opening wells and the pressure recovery of closing wells, the well test curve is drawn and the flow stage is divided, the characteristics of the boundary flow stage curve are judged based on the well test software diagnostic tool, and the corresponding boundary model is selected based on different characteristics. At the same time, the nonlinear seepage equation of low permeability reservoirs is considered. After the model is fitted, the distance parameter Li from the well to the closed boundary is compared with the well spacing to determine the connectivity of the sand body; The sand body boundary is determined by dynamic verification: the connectivity of the sand body is determined by the exciting response formed by the closing and opening of oil and water wells; The dynamic monitoring data are used to determine the boundaries of the sand body: the water flooding front test and tracer test are used to determine the water flooding range, sweep width, etc., and verify the connectivity of the sand body.

5. The method for adjusting the well pattern of oil and gas field development according to claim 2, characterized in that: It also includes applying a random forest regression algorithm to perform regression processing on the calculated effectiveness of the well group, the superposition relationship of single sand bodies, and the width-to-thickness ratio of single sand bodies to obtain the classification boundary of the single sand body contact relationship.

6. The method for adjusting the well pattern of oil and gas field development according to claim 5, characterized in that: The classification boundaries of the single sand body contact relationship include: When the single sand body width-to-thickness ratio is <40, it is isolated type; when the single sand body width-to-thickness ratio is 40<single sand body width-to-thickness ratio is <60, it is superimposed type; when the single sand body width-to-thickness ratio is >60, it is cut-and-stacked type.

7. The method for adjusting the well pattern of oil and gas field development according to claim 1, characterized in that: The adjusting of the well pattern according to the single sand body after the characterization process specifically includes: According to the distribution of single sand bodies and the contact type of single sand bodies, the well pattern adjustment is completed by 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 a cut-and-stack type, it has a complete injection and production system and is developed using a conventional injection and production well pattern. When the width-to-thickness ratio of a single sand body is less than 40, that is, the contact type is isolated, there is a mismatch between injection and production in some parts, including injection without production and production without injection. The same-well injection-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. Different single sand bodies in the vertical direction form separate injection-production systems to improve water drive efficiency.

8. An oil and gas field development well pattern adjustment system, characterized in that: include: Data acquisition module: used to obtain reservoir data; Data processing module: using the obtained reservoir data to perform data processing on the effectiveness of the well group and the characterization of the single sand body; Data simulation module: used to simulate the processed data.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for adjusting the well pattern for oil and gas field development described in any one of claims 1-7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for adjusting the well pattern for oil and gas field development described in any one of claims 1 to 7 are implemented.

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