Interlayer plugging property evaluation method and device for gentle slope terrace oil reservoir, equipment and medium

Abstract

The invention relates to an interlayer plugging performance evaluation method and device for a gentle slope platform oil reservoir, equipment and a medium, in particular to the field of oil-gas field development, and the method comprises the steps that S1, high-frequency cycle division is conducted on a target oil field, and an isochronous stratigraphic framework is established; s2, main control factors of marine gentle slope carbonate rock platform reservoir deposition are determined; s3, determining an interlayer development mechanism and interlayer development influence factors; s4, interlayer porosity characteristics are analyzed, inter-well porosity is compared, and then interlayer depicting is carried out; and S5, performing interlayer plugging performance evaluation based on the characteristic parameters obtained by interlayer depiction. According to the interlayer plugging performance evaluation method provided by the invention, through a specific evaluation process, effective depiction of the marine gentle slope carbonate rock platform oil reservoir interlayer is realized, a basis is provided for accurate plugging performance evaluation of the interlayer, and finally, the plugging performance evaluation of the interlayer is effectively realized, so that a development strategy can be optimized, longitudinal water content breakthrough can be effectively delayed, and the development efficiency is improved. The oilfield development effect is improved.

Description

Technical Field

[0001] The present invention relates to the field of oil and gas field development, and specifically to a method and device, equipment and medium for evaluating the plugging performance of interlayers in gentle slope platform oil reservoirs, and in particular to a method and device, equipment and medium for characterizing and evaluating the plugging performance of interlayers in marine gentle slope carbonate platform oil reservoirs. Background Art

[0002] Marine gentle slope carbonate platform reservoirs are affected by sea level fluctuations, hydrodynamic changes, weathering, leaching, dissolution, cementation, etc. The reservoirs are highly heterogeneous and usually have many thin interlayers. If the interlayers are not clearly understood, there will be greater uncertainty in the vertical pressure conduction, water injection effect, and reserve utilization of the reservoir. However, interlayers are not entirely unfavorable factors for oilfield development. If the interlayers can be accurately characterized and their sealing properties evaluated, and then targeted development strategy adjustments can be made, the vertical water breakthrough can be effectively delayed and the oilfield development effect can be improved.

[0003] At present, there are relatively few studies on the characterization of interlayers in gentle slope carbonate platform reservoirs in the industry. Commonly used characterization methods include GR curve division method, inter-well reservoir comparison method, etc.

[0004] However, the overall mud content in carbonate reservoirs is low, and there is no clear GR boundary value between reservoirs and non-reservoir layers. The GR curve is only sensitive to the longitudinal changes of thick layers, but not to thin layers. The interlayers in the gentle slope carbonate platform reservoirs are mainly thin layers. Therefore, it is unreliable to use the GR curve to divide interlayers.

[0005] The inter-well reservoir comparison method mainly uses the logging interpretation conclusions (oil / gas / water / dry layer, etc.) for inter-well comparison. Affected by the quality of logging curves, human factors, and interpretation methods, the accuracy of logging interpretation varies, especially for the interpretation of thin layers, which has a strong multi-solution. At the same time, the physical properties of interlayers also change laterally. The same interlayer may be judged as different interpretation conclusions in different well groups due to differences in physical properties, affecting the inter-well comparison and integrity of the interlayer. Therefore, the existing thin interlayer characterization methods have great limitations.

[0006] In summary, although there is a certain research basis for the evaluation of the sealing property of carbonate interlayers, such as numerical simulation methods, it is impossible to accurately establish an interlayer model in the geological model due to the inability to accurately characterize the interlayers. As a result, the interlayer thickness, physical properties, lateral continuity, etc. in the numerical simulation are not objective and accurate, and therefore have great uncertainty and multiple solutions. Summary of the invention

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method and device, equipment, and medium for evaluating the plugging properties of interlayers in gentle slope platform oil reservoirs, so as to solve the current problems of being unable to accurately characterize interlayers and accurately establish interlayer models in geological models, which in turn leads to the inability to effectively evaluate the plugging properties of interlayers.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for evaluating the plugging performance of an interlayer in a gentle slope platform oil reservoir, the method comprising:

[0010] S1. Divide the target oil field into high-frequency cycles and establish an isochronous stratigraphic framework;

[0011] S2. Determine the main controlling factors of reservoir deposition in marine gentle slope carbonate platform;

[0012] S3. Determine the mechanism of interlayer development and the factors affecting interlayer development;

[0013] S4, analyze the porosity characteristics of interlayers and compare the porosity between wells, and then characterize the interlayers;

[0014] S5. Evaluate the plugging performance of the interlayer based on the characteristic parameters obtained from the interlayer characterization.

[0015] The interlayer plugging property evaluation method provided by the present invention realizes the effective characterization of the interlayer in the marine gentle slope carbonate platform oil reservoir through a specific evaluation process, provides a basis for the accurate plugging property evaluation of the interlayer, and finally effectively realizes the evaluation of the plugging property of the interlayer, thereby optimizing the development strategy, effectively delaying the vertical water breakthrough, and improving the oilfield development effect.

[0016] As a preferred technical solution of the present invention, the high-frequency cycle division includes: obtaining high-frequency cycles based on regional sequence stratigraphic characteristics of marine gentle slope carbonate platform oil reservoirs, GR curve characteristics of oil wells and vertical development characteristics of reservoirs.

[0017] Preferably, the establishment of an isochronous stratigraphic framework comprises: dividing high-frequency cycles on a single well, and performing inter-well comparison to establish an isochronous stratigraphic framework of high-frequency cycles within the oil field; then, under the constraints of the high-frequency cycles of the oil field, using the typical marker layers of the region as constraints of the isochronous interfaces, and utilizing the vertical variation trends of the reservoir thickness and physical properties to divide the top and bottom interfaces of the sub-layers, with each sub-layer being an isochronous stratum, and further subdividing to obtain an isochronous stratigraphic framework.

[0018] As a preferred technical solution of the present invention, the determination of the main controlling factors of reservoir deposition in marine gentle slope carbonate platform includes: analyzing the influencing factors of sedimentary microfacies evolution and changes in distribution range in each period based on sedimentary microfacies and high-frequency cycles, and clarifying the main controlling factors of reservoir deposition.

[0019] Preferably, the sedimentary microfacies is obtained by combining regional paleo-geomorphology and regional sedimentary background through core analysis and thin section observation.

[0020] As a preferred technical solution of the present invention, the determination of the interlayer development mechanism includes: determining the deposition mechanism, lateral stability and local differences of the interlayer based on the main controlling factors of reservoir deposition.

[0021] Preferably, the factors affecting interlayer development include: obtaining the interlayer sections that are favorable for interlayer development based on the interlayer development mechanism and high-frequency cycles, and then determining the factors affecting interlayer development in combination with regional weathering, leaching and dissolution characteristics.

[0022] As a preferred technical solution of the present invention, the analysis of interlayer porosity characteristics includes: clarifying the characteristics of reduced porosity of interlayers relative to surrounding rocks based on the interlayer development mechanism, the understanding of interlayer deposition mechanism and the influencing factors of interlayer development, and determining interlayers containing porosity return characteristics.

[0023] Preferably, the inter-well porosity comparison includes: combining the isochronous stratigraphic framework and the layers with favorable interlayer development, comparing the porosity curve change trends of all wells in the study area within the isochronous framework, and comparing and connecting the stable, isochronous layers with porosity return characteristics.

[0024] Preferably, the interlayer characterization includes: establishing a well-connected profile based on an isochronous stratigraphic framework and comparing inter-well porosity results, and comparing the characterized interlayer with an isochronous interface to perform interlayer characterization.

[0025] Preferably, in the interlayer characterization, only interlayers that can be identified and tracked in all wells, have stable thickness, are parallel to different interlayers, and are also parallel to the isochronous grid are identified as interlayers. At the same time, the depth of the top and bottom half-width points of the interlayer obtained in a single well is used as the depth value of the interlayer characterization.

[0026] As a preferred technical solution of the present invention, the interlayer plugging evaluation includes: making an intersection chart based on the thickness and average porosity of the interlayers depicted on each well obtained by interlayer characterization and the depletion pressure difference on both sides of the interlayer, clarifying the thickness and porosity limit value of the interlayer with plugging properties, calculating the depletion pressure difference on both sides of the interlayer, and evaluating the plugging properties of the interlayer.

[0027] Preferably, if the depletion pressure difference on both sides of the interlayer is less than 0.2 MPa, the plugging property of the interlayer is weak.

[0028] Preferably, if the depletion pressure difference on both sides of the interlayer is between 0.2-0.5 MPa, the plugging property of the interlayer is medium.

[0029] Preferably, if the depletion pressure difference on both sides of the interlayer is greater than 0.5 MPa, the plugging property of the interlayer is strong.

[0030] As a preferred technical solution of the present invention, after the interlayer plugging evaluation is completed, the reliability of the optimized interlayer characterization and plugging evaluation is evaluated by finely characterizing the interlayer with the help of geological models, dynamic analysis and numerical simulation verification.

[0031] Preferably, the geological model finely characterizes the interlayers, including: based on the interlayer characterization results, counting the top and bottom depths of the interlayers characterized on the wells, obtaining the top and bottom depth structural surfaces of each interlayer by interpolation between wells in a dense well network, and then using the top and bottom depth structural surfaces of each interlayer to establish a stratigraphic unit for each interlayer separately, and then using the thickness of the interlayer with sealing properties and the porosity limit value to calculate the net-to-gross ratio model of the interlayer, assigning the net-to-gross ratio of the interlayer grid with sealing properties to 0, and assigning the net-to-gross ratio of the grid with weak sealing properties to 1, thereby achieving fine characterization of the interlayers.

[0032] Preferably, based on the results of fine characterization of interlayers by geological models, dynamic analysis is carried out in combination with the effective time of water injection of the water injection well group and the water breakthrough time of the oil wells. At the same time, numerical simulation of the reservoir is carried out on the net-to-gross ratio parameters obtained by fine characterization of interlayers by geological models, and the reliability of interlayer characterization and plugging evaluation is verified using the pressure fitting rate and water cut fitting rate of the water injection well group.

[0033] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0034] (1) The plugging performance evaluation method provided by the present invention can accurately characterize the interlayers in the marine gentle slope carbonate platform reservoir, thereby achieving an objective evaluation of the plugging performance of the interlayers.

[0035] (2) The objective evaluation of the plugging property of interlayers improves the accuracy of dynamic analysis of reservoir development. In the process of waterflooding development in oil fields, the evaluation results of the plugging property of interlayers can be combined to propose targeted development strategies and improve the effect of waterflooding development. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flow chart of a method for evaluating the sealing performance of an interlayer in a gentle slope platform oil reservoir provided by an embodiment of the present invention;

[0037] Figure 2 It is a schematic diagram of an interlayer plugging performance evaluation device for a gentle slope terrace oil reservoir provided by an embodiment of the present invention;

[0038] Figure 3 is a schematic diagram of an electronic device provided by an embodiment of the present invention;

[0039] Figure 4 is the sequence cycle division diagram of the target work area obtained in Example 1 of the present invention;

[0040] Figure 5 is the isochronous stratigraphic grid diagram of the target work area obtained in Example 1 of the present invention;

[0041] Figure 6 This is a schematic diagram of the paleo-geomorphology and sea level fluctuations of the target work area obtained in Example 1 of the present invention;

[0042] Figure 7 This is a cross-sectional diagram of the interlayer characterization and well connection in the target work area obtained in Example 1 of the present invention;

[0043] Figure 8 This is an example of evaluation of the plugging performance of the interlayer in the target work area obtained in Example 1 of the present invention;

[0044] Fig. 9 This is the evaluation chart of the interlayer plugging performance of the target work area obtained in Example 1 of the present invention.

[0045] In the figure: 10 - electronic device, 11 - processor, 12 - ROM, 13 - RAM, 14 - bus, 15 - I / O interface, 16 - input unit, 17 - output unit, 18 - storage unit, 19 - communication unit.

[0046] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0047] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0048] This embodiment provides a method for evaluating the plugging performance of interlayers in a marine gentle slope platform reservoir. The process is as follows: Figure 1 As shown, the method includes:

[0049] S1. Divide the target oil field into high-frequency cycles and establish an isochronous stratigraphic framework;

[0050] S2. Determine the main controlling factors of reservoir deposition in marine gentle slope carbonate platform;

[0051] S3. Determine the mechanism of interlayer development and the factors affecting interlayer development;

[0052] S4, analyze the porosity characteristics of interlayers and compare the porosity between wells, and then characterize the interlayers;

[0053] S5. Evaluate the sealing performance of the interlayer based on the characteristic parameters obtained from the interlayer characterization.

[0054] The high-frequency cycle division includes: dividing the high-frequency cycle according to the regional sequence stratigraphic characteristics of the marine gentle slope carbonate platform oil reservoir, the GR curve characteristics of the oil well and the vertical development characteristics of the reservoir.

[0055] In the present invention, in the high-frequency cycle division, in the development of marine carbonate reservoirs, the GR curve obtained by logging can indicate the level of mud content in the sediment. The higher the GR value, the higher the mud content in the formation, and then the higher the sea level. The vertical fluctuation of the GR curve can indicate the fluctuation of the sea level to a certain extent. Under the constraints of the regional sequence stratigraphic framework caused by the overall fluctuation of the global sea level, the vertical fluctuation of the GR curve within the oil field and the distribution of the vertical development characteristics of the reservoir can be used to further subdivide the sequence stratigraphic framework and obtain the high-frequency cycle within the oil field.

[0056] The establishment of an isochronous stratigraphic framework comprises: dividing high-frequency cycles on a single well, and performing inter-well comparison to establish an isochronous stratigraphic framework of high-frequency cycles within the oil field; then, under the constraints of the high-frequency cycles of the oil field, using the typical marker layers of the region as the constraints of the isochronous interface, and using the vertical variation trends of the reservoir thickness and physical properties to divide the top and bottom interfaces of the small layers, with each small layer being an isochronous stratum, and then subdividing to obtain an isochronous stratigraphic framework.

[0057] For example, in the process of establishing an isochronous stratigraphic framework, high-frequency cycles are divided on a single well, and well-to-well comparison is performed to establish an isochronous high-frequency cycle framework within the oil field. Then, based on the principle of "cycle comparison and hierarchical control", under the constraints of the high-frequency cycles of the oil field, the regional typical marker layers are used as constraints for smaller-scale isochronous interfaces, and the vertical variation trends of reservoir thickness, physical properties, etc. are used to divide the top and bottom interfaces of the small layers, and each small layer is considered to be an isochronous stratum, and then further subdivided to obtain an isochronous stratigraphic framework.

[0058] In the present invention, the sub-layer division is carried out based on high-frequency cycles, regional typical marker layers and reservoir development characteristics.

[0059] In the present invention, the division of regional typical marker layers is carried out based on special geological events during the deposition period, for example, the stratum has the special properties of high porosity and low resistivity.

[0060] The determination of the main controlling factors of reservoir deposition in the marine gentle slope carbonate platform includes: analyzing the influencing factors of sedimentary microfacies evolution and changes in distribution range in each period based on sedimentary microfacies and high-frequency cycles, and clarifying the main controlling factors of reservoir deposition.

[0061] In the present invention, the principle of determining the main controlling factors of reservoir deposition in marine gentle slope carbonate platform is that in the relatively stable gentle slope platform paleo-geomorphology, the evolution of sedimentary microfacies in each period and the changes in distribution range are mainly affected by the high-frequency fluctuations of sea level. Therefore, in the absence of major tectonic movements, the main controlling factor of the sedimentary microfacies of the gentle slope platform is the fluctuation of sea level.

[0062] The sedimentary microfacies are obtained by combining regional paleo-geomorphology and regional sedimentary background through core analysis and thin section observation.

[0063] Wherein, the determination of the interlayer development mechanism includes: determining the deposition mechanism, lateral stability and local differences of the interlayer according to the main controlling factors of reservoir deposition.

[0064] Wherein, the determination of the depositional mechanism of the interlayer includes: determining the reservoir development categories of sea level rise and sea level retreat.

[0065] Wherein, the determination of lateral stability includes: determining whether the "differential reservoir" deposited by sea level rise is continuously distributed on the plane.

[0066] Wherein, determining the local differences includes: determining whether there is local development of coarse-grained deposits in the interlayer.

[0067] For example, when the sea level rises during the process of determining the interlayer development mechanism, the sedimentary hydrodynamics weakens, and marl deposits mainly develop. After the sea retreats, a stably developed "poor reservoir", that is, an interlayer, is left behind. This is the sedimentary mechanism of the marine gentle slope platform interlayer. Since the sea level rise is globally consistent, the "poor reservoir" deposited by the sea level rise is continuously distributed on the plane, so the interlayer has lateral stability. Due to the undulating ancient landforms and the differences in the depth of local water bodies, the hydrodynamics will also be different. Therefore, although the interlayer is generally fine-grained sediments such as marl, there is also the possibility of locally developing relatively coarse-grained sediments such as granular limestone, muddy granular limestone, etc., that is, the physical properties of the interlayer have local differences.

[0068] Among them, the factors affecting interlayer development include: obtaining the layer section that is favorable for interlayer development based on the interlayer development mechanism and high-frequency cycles, and then determining the factors affecting interlayer development in combination with regional weathering, leaching and dissolution characteristics.

[0069] For example, through the interlayer development mechanism, it can be determined that the interlayer mainly develops in the period of high sea level, and then through high-frequency cycles, it can be judged that the small layer with relatively high sea level is a favorable interlayer deposition section, thereby obtaining a section that is favorable for the development of interlayers. At the same time, since weathering, leaching and dissolution mainly occur when carbonate rocks are exposed at sea level and are damaged by atmospheric precipitation, it is easy to form weathering and dissolution holes. According to the interlayer development mechanism, the interlayer of the marine gentle slope carbonate platform was formed in the period of relatively high sea level. The study area is located below the sea level as a whole and is not exposed to the water surface. Therefore, it is free from weathering and leaching by natural factors such as atmospheric precipitation, and there are no conditions for the formation of large holes. Therefore, it is determined that the main influencing factor for the development of interlayers is sedimentation, and the controlling factor of interlayer porosity is sedimentation, which is not affected by weathering and leaching.

[0070] The analysis of interlayer porosity characteristics includes: clarifying the characteristics of reduced porosity of interlayers relative to surrounding rocks based on the interlayer development mechanism, the understanding of interlayer deposition mechanism and the influencing factors of interlayer development, and determining interlayers with porosity return characteristics.

[0071] In the present invention, it is not necessary to cutoff the porosity of the interlayer in the process of analyzing the porosity characteristics of the interlayer. Since the hydrodynamics during the deposition of the interlayer are weak and the sedimentary grain size is fine, the porosity of the interlayer is relatively low. The low porosity of the interlayer is a relative high and low, which means that the low porosity of the interlayer is relative to the porosity of the upper and lower surrounding rocks, that is, the porosity return characteristics of the interlayer clamped by the high-porosity reservoir. The sedimentary hydrodynamics of the interlayer have local differences, and the absolute value of its porosity also has high and low differences. Therefore, in the identification process of the interlayer, it is necessary to pay attention to the return characteristics of the interlayer, rather than its absolute value. For example, the porosity of the top and bottom surrounding rock reservoirs may reach 18-20%, while the porosity of the middle interlayer may be only 4% (the data is only for example), which is significantly lower than the porosity of the surrounding rock.

[0072] Among them, the inter-well porosity comparison includes: combining the isochronous stratigraphic framework and the layers with favorable interlayer development, comparing the porosity curve change trends of all wells in the study area within the isochronous framework, and comparing and connecting the stable, isochronous layers with porosity return characteristics.

[0073] In the present invention, since the interlayer develops stably on the plane and is not easily affected by weathering and leaching, its low porosity characteristics have plane stability. The low-porosity layer seen in a single well is not necessarily an interlayer. The determination of the interlayer needs to meet the requirements of relatively low porosity (return characteristics) and that all wells in the whole area can be compared. Both conditions are indispensable, and interlayer comparison between wells is carried out on this basis.

[0074] The interlayer characterization includes: establishing a well-connected profile based on an isochronous stratigraphic framework and comparing inter-well porosity results, and comparing the characterized interlayer with the isochronous interface to perform interlayer characterization.

[0075] In the present invention, only interlayers that can be identified and tracked in all wells, have stable thickness, and are parallel to each other and to the isochronous grid are identified as interlayers in interlayer characterization. The depth of the top and bottom half-width points of the interlayer obtained in a single well will be used as the depth value of interlayer characterization.

[0076] In the present invention, stable thickness means that the thickness of the same interlayer in different places does not vary much. The specific thickness is related to the thickness of the reservoir and is confirmed based on actual conditions. For example, when the thickness of the reservoir is 80m, the thickness of the interlayer within 0.5-2m is considered to be stable.

[0077] Among them, the evaluation of the plugging property of the interlayer includes: making an intersection chart based on the thickness and average porosity of the interlayers depicted on each well obtained by the interlayer characterization and the depletion pressure difference on both sides of the interlayer, clarifying the thickness and porosity limit value of the interlayer with plugging properties, calculating the depletion pressure difference on both sides of the interlayer, and evaluating the plugging property of the interlayer.

[0078] In the present invention, when the interlayer has plugging properties, the upper and lower connectivity of the interlayer is poor, and the recovery degree of the upper and lower oil layers of the interlayer will be different during the development of the oil field, which will lead to inconsistent depletion degrees of the oil layers on both sides of the interlayer, and there is a depletion pressure difference. Based on the dynamic analysis of the oil reservoir, the limit value of the depletion pressure difference of the interlayer with plugging properties is clarified.

[0079] Among them, if the depletion pressure difference on both sides of the interlayer is less than 0.2MPa, the interlayer sealing property is weak; if the depletion pressure difference on both sides of the interlayer is between 0.2-0.5MPa, the interlayer sealing property is medium; if the depletion pressure difference on both sides of the interlayer is greater than 0.5MPa, the interlayer sealing property is strong.

[0080] Furthermore, the reliability of optimized interlayer characterization and plugging evaluation can be evaluated by finely characterizing interlayers with the help of geological models, dynamic analysis and numerical simulation verification.

[0081] Among them, the use of geological models to finely characterize interlayers includes: based on the interlayer characterization results, the top and bottom depths of the interlayers characterized on the wells are counted, and the top and bottom depth structural surfaces of each interlayer are obtained by interpolation between wells in a dense well network. Then, the top and bottom depth structural surfaces of each interlayer are used to establish a stratigraphic unit for each interlayer. Then, the thickness of the interlayer with sealing properties and the porosity limit value are used to calculate the net-to-gross ratio model of the interlayer, and the net-to-gross ratio of the interlayer with sealing properties is assigned to 0, and the net-to-gross ratio of the grid with weak sealing properties is assigned to 1, thereby achieving fine characterization of the interlayers.

[0082] In the present invention, in the subsequent numerical simulation process in the continuous simulation, the sandwich grid with a net-to-gross ratio of 0 has a plugging property.

[0083] Based on the results of fine characterization of interlayers by geological model, dynamic analysis was carried out in combination with the effective time of water injection by water injection well group and the water breakthrough time of oil wells. At the same time, numerical simulation of reservoir was carried out on the net-to-gross ratio parameters obtained by fine characterization of interlayers by geological model, and the reliability of interlayer characterization and plugging evaluation was verified by using the pressure fitting rate and water cut fitting rate of water injection well group.

[0084] Furthermore, the present invention provides a device for evaluating the sealing performance of interlayers in marine gentle slope platform oil reservoirs, such as Figure 2 As shown, the device comprises:

[0085] Isochronous stratigraphic framework building module, used to divide the target oil field into high-frequency cycles and build an isochronous stratigraphic framework;

[0086] The main controlling factor acquisition module is used to determine the main controlling factors of marine gentle slope carbonate platform reservoir deposition;

[0087] Interlayer parameter acquisition module, used to determine the interlayer development mechanism and factors affecting interlayer development;

[0088] Interlayer characterization module, used to analyze interlayer porosity characteristics and compare interwell porosity, and then perform interlayer characterization;

[0089] An evaluation module is used to evaluate the plugging performance of interlayers based on characteristic parameters obtained from interlayer characterization.

[0090] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0091] Further, the present invention provides an electronic device, which is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0092] like Figure 3 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. The I / O interface 15 is also connected to the bus 14.

[0093] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0094] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the interlayer plugging evaluation method for the gentle slope platform reservoir.

[0095] In some embodiments, the interlayer plugging evaluation method for a gentle slope platform oil reservoir can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the interlayer plugging evaluation method for a gentle slope platform oil reservoir described above can be executed. Alternatively, in other embodiments, the processor 11 can be configured to execute the interlayer plugging evaluation method for a gentle slope platform oil reservoir in any other appropriate manner (for example, by means of firmware).

[0096] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0097] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0098] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0099] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0100] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0101] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0102] The server provided in this embodiment includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the interlayer plugging property evaluation method for the gentle slope platform oil reservoir is implemented.

[0103] Unless otherwise specifically stated, terms such as processing, computing, calculating, determining, displaying, etc. may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, which operate and convert data represented as physical (e.g., electronic) quantities within registers or memories of a processing system into other data similarly represented as physical quantities within memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0104] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments of the present invention may all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described around their functions. Whether such functions are implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system. A skilled person may implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present disclosure.

[0105] The steps of the method or algorithm described in conjunction with the embodiments herein may be directly embodied as hardware, a software module executed by a processor, or a combination thereof. The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a mobile disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and the storage medium may also be present in a user terminal as discrete components.

[0106] For software implementation, the techniques described in the present invention can be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described in the present application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or outside the processor. In the latter case, it is coupled to the processor in a communication manner via various means, which are well known in the art.

[0107] Further, in order to illustrate the effect that can be achieved by the interlayer plugging evaluation method provided by the present invention, the following actual example is used for exemplary description, as follows:

[0108] Example 1

[0109] This embodiment provides a new method for describing the interlayer of marine gentle slope carbonate platform reservoir, accurately characterizing the interlayer with geological model, and evaluating the plugging property of the interlayer based on conventional logging data. Taking the M oil field as an example, the details are as follows:

[0110] Step 1: Through the regional survey of M Oilfield, combined with the GR curve characteristics of all wells in M ​​Oilfield, the vertical development characteristics of the reservoir, and the comprehensive analysis of the regional sequence stratigraphic characteristics, the high-frequency cycle division is confirmed that the target layer section of M Oilfield as a whole belongs to a long-term decline semi-cycle, and can be further subdivided into 3 medium-term decline semi-cycles and 2 medium-term rise semi-cycles. Combined with the cycle characteristics and reservoir development, the target layer section is divided into 8 small layers from bottom to top, namely VIII / VII / VI / V / IV / III / II / I, as shown in Figure 1. Figure 4 As shown. Sublayer VIII to the middle of sublayer VII is the first mid-term descending half-cycle, with the highest sea level in sublayer VIII, and the sea level gradually decreases from bottom to top; from the middle of sublayer VII to the middle of sublayer VI, the sea level gradually begins to rise, forming the first rising half-cycle; from the middle of sublayer VI to the middle of sublayer V, the sea level drops again, forming the second descending half-cycle; from the middle of sublayer V to the lower part of sublayer IV, the sea level rises again, forming the second rising half-cycle; from the lower part of sublayer IV to sublayer I, the sea level continues to drop, forming the third descending half-cycle. The fluctuation of sea level is globally uniform, therefore, the same sublayer in different wells within the M oilfield is isochronous. Using the top and bottom interfaces of the sublayers, an isochronous stratigraphic framework is established, such as Figure 5 At the same time, both sublayers V and VII have the special properties of high porosity and low resistivity, representing special geological events during the sedimentary period and can be used as isochronous marker layers, further confirming the rationality of the isochronous framework.

[0111] Step 2: The paleo-geomorphology of the target layer of the M oilfield is a coastal gentle slope. Through core and thin section observation, it is mainly developed with bioclastic granular limestone, marl, etc., which belongs to the gentle slope carbonate platform facies as a whole. The main sedimentary microfacies developed are bioclastic beach microfacies and open sea microfacies. Because the paleo-geomorphology is gentle and stable, the reservoir deposition is greatly affected by sea level fluctuations, that is, the main controlling factor is sea level fluctuations, such as Figure 6 As shown in the figure, we can see the following: the lower the sea level, the shallower the water body, the stronger the hydrodynamics, the coarser the sedimentary particles, and the better the reservoir properties. Conversely, the higher the sea level, the deeper the water body, the weaker the hydrodynamics, the finer the sedimentary particles, and the worse the reservoir properties.

[0112] Step 3, the development process of the interlayer follows the sedimentation process obtained in step 2. When the sea level rises, the sedimentary hydrodynamics weakens, and fine-grained sediments are stably developed throughout the M oilfield, mainly marl deposits. After the sea retreats, a stably developed "poor reservoir", namely the interlayer, is left behind. Due to the undulating ancient landforms, the depth of local water bodies varies, and the hydrodynamics also vary. Therefore, although the interlayer is fine-grained as a whole, there is also the possibility of relatively coarse-grained sediments developing locally. Therefore, the physical properties of the interlayer are also locally different. The length of time that the sea level remains high after rising determines the thickness of the interlayer. The sea level rise in the M oilfield is mainly short-term, and thin interlayers are mostly developed.

[0113] Based on the analysis of the mid-term cycle in step 1, the sea level of sublayers VIII, VI, and III-IV is relatively high, and interlayers are easy to develop. Since the water body was deep during the deposition period and did not emerge from the water surface to be weathered and leached, the interlayers did not dissolve and retained poor physical properties.

[0114] Step 4. On the basis of step 3, due to the weak hydrodynamics and fine sedimentary grain size during the interlayer deposition period, the interlayer porosity is relatively low. The low interlayer porosity is a relative high and low, and there should be no clear absolute value standard. The low interlayer porosity is relative to the porosity of the upper and lower surrounding rocks, that is, the interlayer porosity return characteristics clamped by high-porosity reservoirs. According to the conclusion obtained in step 3: the sedimentary hydrodynamics of the interlayer have local differences, and the absolute value of its porosity also has high and low differences. Therefore, in the identification process of the interlayer, it is necessary to pay attention to the return characteristics of the interlayer, rather than its absolute value.

[0115] Based on step 3, since interlayers develop stably on the plane and are not easily affected by weathering and leaching, their physical properties such as low porosity have plane stability. Therefore, the low-porosity intervals seen in a single well are not necessarily interlayers. The determination of interlayers requires both low porosity and stable development in the entire area. Both conditions are indispensable.

[0116] Based on steps 1 and 3, interlayers were identified along the isochronous framework in the favorable interlayer development intervals (VIII sublayer, VI sublayer, III-IV sublayer). The porosity curves of all wells in the M oil field were compared horizontally, and finally six thin interlayers with stable development in the entire oil field were characterized, such as Figure 7 As shown in the figure, there are 3 VIII sublayers, 2 VI sublayers, and 1 IV sublayer. These 6 thin interlayers can be identified and traced in all wells, with stable thickness, and the interlayers are parallel to each other and to the isochronous framework, that is, each interlayer is isochronous, and the characterization of the 6 interlayers is accurate and reasonable.

[0117] Step 5. Select all the pressure measurement data of the M oil field and compare the depletion pressure values ​​on both sides of the interlayer. It is analyzed that when the depletion pressure difference on both sides of the interlayer is lower than 0.2MPa, the interlayer has weak plugging and strong connectivity; when the depletion pressure difference on both sides of the interlayer is 0.2-0.5MPa, the interlayer has medium plugging and has certain connectivity; when the depletion pressure difference on both sides of the interlayer is higher than 0.5MPa, the interlayer has strong plugging and has obvious isolation effect on the longitudinal conduction of fluid and pressure, such as Figure 8 shown.

[0118] Based on step 4, the six interlayers are finely characterized, and the parameters affecting the permeability, such as the thickness and porosity of the interlayers, can be directly obtained by statistics. The thickness and porosity of the interlayers characterized by the statistics are intersected with the depletion pressure difference on both sides of the interlayers, such as Fig. 9 As shown in the figure, interlayers with weak plugging and strong connectivity have an average porosity of >11% and a thickness of <0.5m; interlayers with medium plugging and certain connectivity have an average porosity of 8-11% and a thickness of 0.5-0.9m; interlayers with strong plugging and significant impact on production have an average porosity of <8% and a thickness of >0.9m.

[0119] Step 6: Count the top and bottom depths of the six interlayers depicted on the well, and interpolate the top and bottom depth structural surfaces of the six interlayers respectively.

[0120] Since the six interlayers are relatively thin, in order to avoid coarsening of the interlayers and maintain their integrity during the geological modeling process, the top and bottom surfaces of the six interlayers are used to establish a separate stratigraphic unit (zone) for each interlayer, thereby retaining the authenticity and objectivity of parameters such as interlayer thickness and porosity to the greatest extent, and achieving a detailed characterization of the interlayers.

[0121] Calculate the net-to-gross ratio model of the interlayer. Based on the lower limit of the interlayer parameter with strong plugging properties obtained in step 5, screen the grids with porosity < 8% and thickness > 0.9m, assign the net-to-gross ratio to 0, and assign the net-to-gross ratio of the remaining grids to 1.

[0122] Step 7. Based on the detailed characterization of interlayers in step 6, a dynamic analysis of the water injection well group in the M oil field is performed. The analysis shows that under the condition that the distance between injection and production wells is basically the same, in the position where the interlayer plugging is weak, the injection and production effect time is about 2 months, the effect is relatively obvious, and the oil wells see water for about 300 days; in the position where the interlayer plugging is strong, due to the shielding of the interlayer, the injection and production effect time is about 4 months, and the effect is relatively weak, and the oil wells see water for more than 800 days or no water. The above analysis shows that interlayers with strong plugging properties have obvious hysteresis effects on injection and production effects, pressure conduction, and fluid exchange, and also verifies the rationality of the interlayer characterization and plugging evaluation results.

[0123] The net-to-gross ratio and other attributes of the geological model established in step 6 were output for reservoir numerical simulation. The historical fitting results showed that the pressure fitting rate and water cut fitting rate of the water injection well group were about 15% higher than those of the model without interlayer characterization, which further verified the reliability of the interlayer characterization and plugging evaluation results.

[0124] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0125] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0126] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for evaluating the plugging performance of interlayers in a gentle slope platform oil reservoir, characterized in that: The interlayer plugging evaluation method comprises: S1. Divide the target oil field into high-frequency cycles and establish an isochronous stratigraphic framework; S2. Determine the main controlling factors of reservoir deposition in marine gentle slope carbonate platform; S3. Determine the mechanism of interlayer development and the factors affecting interlayer development; S4, analyze the porosity characteristics of interlayers and compare the porosity between wells, and then characterize the interlayers; S5. Evaluate the plugging performance of the interlayer based on the characteristic parameters obtained from the interlayer characterization.

2. The interlayer plugging evaluation method according to claim 1, characterized in that: The high-frequency cycle division includes: obtaining high-frequency cycles according to the regional sequence stratigraphic characteristics of the marine gentle slope carbonate platform oil reservoir, the GR curve characteristics of the oil well and the vertical development characteristics of the reservoir; Preferably, the establishment of an isochronous stratigraphic framework comprises: dividing high-frequency cycles on a single well, and performing inter-well comparison to establish an isochronous stratigraphic framework of high-frequency cycles within the oil field; then, under the constraints of the high-frequency cycles of the oil field, using the typical marker layers of the region as constraints of the isochronous interfaces, and utilizing the vertical variation trends of the reservoir thickness and physical properties to divide the top and bottom interfaces of the sub-layers, with each sub-layer being an isochronous stratum, and further subdividing to obtain an isochronous stratigraphic framework.

3. The interlayer plugging evaluation method according to claim 1 or 2, characterized in that: Determining the main controlling factors of reservoir deposition in the marine gentle slope carbonate platform includes: analyzing the influencing factors of sedimentary microfacies evolution and distribution range changes in each period based on sedimentary microfacies and high-frequency cycles, and clarifying the main controlling factors of reservoir deposition; Preferably, the sedimentary microfacies is obtained by combining regional paleo-geomorphology and regional sedimentary background through core analysis and thin section observation.

4. The method for evaluating interlayer sealing performance according to any one of claims 1 to 3, characterized in that: The determination of the interlayer development mechanism includes: determining the deposition mechanism, lateral stability and local differences of the interlayer according to the main controlling factors of reservoir deposition; Preferably, the factors affecting interlayer development include: obtaining the interlayer sections that are favorable for interlayer development based on the interlayer development mechanism and high-frequency cycles, and then determining the factors affecting interlayer development in combination with regional weathering, leaching and dissolution characteristics.

5. The method for evaluating interlayer sealing performance according to any one of claims 1 to 4, characterized in that: The analysis of interlayer porosity characteristics includes: clarifying the characteristics of interlayer porosity reduction relative to surrounding rock based on the interlayer development mechanism, the understanding of interlayer deposition mechanism and the influencing factors of interlayer development, and determining interlayers with porosity return characteristics; Preferably, the inter-well porosity comparison includes: combining the isochronous stratigraphic framework and the layers with favorable interlayer development, comparing the porosity curve change trends of all wells in the study area within the isochronous framework, and comparing and connecting the layers that are stable, isochronous and have porosity return characteristics; Preferably, the interlayer characterization includes: establishing a well-connected profile based on an isochronous stratigraphic framework and comparing interwell porosity results, and comparing the characterized interlayer with an isochronous interface to perform interlayer characterization; Preferably, in the interlayer characterization, only interlayers that can be identified and tracked in all wells, have stable thickness, are parallel to different interlayers, and are also parallel to the isochronous grid are identified as interlayers. At the same time, the depth of the top and bottom half-width points of the interlayer obtained in a single well is used as the depth value of the interlayer characterization.

6. The method for evaluating interlayer sealing performance according to any one of claims 1 to 5, characterized in that: The interlayer plugging evaluation includes: according to the thickness and average porosity of the interlayers depicted on each well obtained by the interlayer characterization, an intersection chart is made with the depletion pressure difference on both sides of the interlayer, the thickness and porosity limit value of the interlayer with plugging properties are determined, the depletion pressure difference on both sides of the interlayer is calculated, and the plugging properties of the interlayer are evaluated; Preferably, if the depletion pressure difference on both sides of the interlayer is less than 0.2 MPa, the plugging property of the interlayer is weak; Preferably, if the depletion pressure difference on both sides of the interlayer is between 0.2-0.5 MPa, the plugging property of the interlayer is medium; Preferably, if the depletion pressure difference on both sides of the interlayer is greater than 0.5 MPa, the plugging property of the interlayer is strong.

7. The method for evaluating interlayer sealing performance according to any one of claims 1 to 6, characterized in that: After the interlayer plugging evaluation is completed, the reliability of optimizing the interlayer characterization and plugging evaluation is evaluated by finely characterizing the interlayer with the help of geological models, dynamic analysis and numerical simulation verification; Preferably, the geological model finely characterizes the interlayers, including: based on the interlayer characterization results, the top and bottom depths of the interlayers characterized on the wells are counted, the top and bottom depth structural surfaces of each interlayer are obtained by interpolation between wells in a dense well network, and then the top and bottom depth structural surfaces of each interlayer are used to separately establish a stratigraphic unit for each interlayer, and then the thickness of the interlayer with plugging properties and the porosity limit value are used to calculate the net-to-gross ratio model of the interlayer, the net-to-gross ratio of the interlayer with plugging properties is assigned to 0, and the net-to-gross ratio of the interlayer with weak plugging properties is assigned to 1, thereby achieving fine characterization of the interlayers; Preferably, based on the results of fine characterization of interlayers by geological models, dynamic analysis is carried out in combination with the effective time of water injection of the water injection well group and the water breakthrough time of the oil wells. At the same time, numerical simulation of the reservoir is carried out on the net-to-gross ratio parameters obtained by fine characterization of interlayers by geological models, and the reliability of interlayer characterization and plugging evaluation is verified using the pressure fitting rate and water cut fitting rate of the water injection well group.

8. An interlayer plugging evaluation device for a gentle slope platform oil reservoir, characterized in that: The interlayer plugging evaluation device comprises: Isochronous stratigraphic framework building module, used to divide the target oil field into high-frequency cycles and build an isochronous stratigraphic framework; The main controlling factor acquisition module is used to determine the main controlling factors of marine gentle slope carbonate platform reservoir deposition; Interlayer parameter acquisition module, used to determine the interlayer development mechanism and factors affecting interlayer development; Interlayer characterization module, used to analyze interlayer porosity characteristics and compare interwell porosity, and then perform interlayer characterization; An evaluation module is used to evaluate the plugging performance of interlayers based on characteristic parameters obtained from interlayer characterization.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively coupled to the at least one processor; Wherein, the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the interlayer plugging evaluation method for a gentle slope platform oil reservoir as described in any one of claims 1-7.

10. A computer storage medium, characterized in that: The computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by a processor, the interlayer plugging property evaluation method for a gentle slope terrace oil reservoir according to any one of claims 1 to 7 is implemented.

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