Method, device and equipment for determining oil reservoir conversion driving time based on oil saturation

Abstract

The application provides a method, device and equipment for determining oil reservoir conversion driving time based on oil saturation, comprising the following steps: determining oil saturation of each target well group according to steam stimulation production data of multiple target well groups; determining heat storage of each target well group when injecting the same steam injection volume at different historical production times; determining a relationship diagram between oil saturation and oil layer heat utilization rate according to the heat storage of each oil layer; and determining the best time for oil reservoir conversion steam drive according to the relationship diagram between oil saturation and oil layer heat utilization rate. Thus, by studying oil layer heat utilization rate under different oil saturation conditions in the steam stimulation process of various types of oil wells, the different oil saturation and oil layer heat utilization rate are fitted, the critical value of oil saturation required for oil reservoir conversion steam drive is inversely deduced according to the fitted relationship diagram, the best time for oil reservoir conversion steam drive is determined according to the critical value of residual saturation, the determination precision of conversion steam drive time is improved, and the overall development effect of the oilfield is improved.

Description

Technical Field

[0001] This invention relates to the field of crude oil development technology, and in particular to a method, apparatus and equipment for determining the timing of reservoir conversion based on oil saturation. Background Technology

[0002] Heavy oil steam injection development is a secondary development of crude oil and a technology for heavy oil thermal recovery. Steam contains a large amount of latent heat, and steam injection has been widely used in the petroleum industry. There are two main technologies used for steam injection: cyclic steam injection and steam drive. When cyclic steam injection reaches its economic limit, it exhibits characteristics such as accelerated decline in crude oil production, decreased production rate, decreased production-injection ratio, worsening development effect, and deteriorating economic benefits. Therefore, when cyclic steam injection reaches its economic limit, it is necessary to determine whether to proceed to tertiary oil recovery, i.e., the steam drive stage. However, the steam drive method involves the establishment of a well network, the construction of surface engineering, and the completion of supporting oil production engineering, making it a large-scale systemic project. Before switching to steam drive, a precise assessment of economic benefits and production volume is required to ensure that the steam drive stage achieves the required reservoir recovery and economic benefits.

[0003] In other words, before switching to steam drive, it is necessary to determine the optimal timing for the switch and to formulate a reasonable conversion scheme. However, current technologies cannot accurately determine the optimal timing for steam drive, which in turn affects the efficient utilization of thermal energy and the overall development effect of the oilfield. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method, apparatus, and equipment for determining the timing of reservoir conversion to steam drive based on oil saturation, thereby solving or partially solving the technical problem that the timing of conversion to steam drive cannot be accurately determined in the prior art, thus affecting the overall development effect of the oilfield.

[0005] A first aspect of the present invention provides a method for determining the timing of reservoir transition based on oil saturation, the method comprising:

[0006] Acquire production data from multiple target well groups during the steam injection process;

[0007] The oil saturation of each target well group is determined based on the production data.

[0008] Determine the heat storage of the oil reservoir when the same amount of steam is injected into each of the target well groups at different historical production times;

[0009] A graph showing the relationship between oil saturation and oil layer thermal utilization rate is determined based on the heat storage of each oil layer.

[0010] The optimal timing for switching to steam drive in an oil reservoir is determined based on the relationship between oil saturation and reservoir thermal utilization rate.

[0011] In the above scheme, the production data includes: production rate, temperature, and perforation parameters; determining the oil saturation of the target well group based on the production data includes:

[0012] The production of the target well group is divided into different producing layers according to the perforation parameters;

[0013] Determine the extraction rate for each producing layer;

[0014] The remaining oil saturation of each production layer is determined based on the original oil saturation of the production layer and the recovery rate of each production layer;

[0015] The target producing layer of the target well group is determined, and the remaining oil saturation of the target producing layer is determined based on the remaining oil saturation of each producing layer; the remaining oil saturation of the target producing layer is the oil saturation of the target well group.

[0016] In the above scheme, determining the heat storage of the oil reservoir under different historical production times when the same amount of steam is injected into each of the target well groups includes:

[0017] For any historical mining time, the heat content of the injected oil layer of each target well group is determined based on the steam injection volume, and the heat produced by each target well group is determined based on the produced fluid temperature.

[0018] The heat storage of the oil layer is determined based on the heat content of the injected oil layer and the heat generated; the heat storage of the oil layer is the difference between the heat content of the injected oil layer and the heat generated.

[0019] In the above scheme, determining the heat content of the injected oil layer in each target well group based on the steam injection volume includes:

[0020] The total injected heat is determined based on the gas injection volume;

[0021] The heat loss along the steam injection path is determined based on the temperature change of the steam.

[0022] The injected oil layer heat content of the target well group is determined based on the total injected heat and the heat loss, wherein the injected oil layer heat content is the difference between the total injected heat and the heat loss.

[0023] In the above scheme, determining the relationship between oil saturation and oil reservoir thermal utilization rate based on the heat storage of the oil reservoir includes:

[0024] The heat utilization rate of the oil reservoir for each target well group is determined based on the heat storage of the oil reservoir.

[0025] Curve fitting was performed on the oil reservoir thermal utilization rate and oil saturation of each target well group to obtain a graph showing the relationship between oil saturation and oil reservoir thermal utilization rate.

[0026] In the above scheme, determining the optimal timing for reservoir conversion to steam drive based on the relationship diagram between oil saturation and reservoir thermal utilization includes:

[0027] The inflection point detection function is used to detect the inflection point in the relationship graph between oil saturation and oil reservoir thermal utilization rate, and the inflection point in the relationship graph is obtained.

[0028] The oil saturation corresponding to the inflection point is determined as the target oil saturation.

[0029] The optimal timing for switching the reservoir to steam drive is determined based on the target oil saturation. The optimal timing is the time when the remaining oil saturation of the reservoir is the target oil saturation.

[0030] A second aspect of the present invention provides an apparatus for determining reservoir transition timing based on oil saturation, the apparatus comprising:

[0031] The acquisition unit is used to acquire production data of multiple target well groups during the steam injection process.

[0032] The first determining unit is used to determine the oil saturation of each target well group based on the production data; determine the heat storage of the oil layer when the same amount of steam is injected into each target well group at different historical production times; and determine the relationship between oil saturation and oil layer heat utilization rate based on the heat storage of each oil layer.

[0033] The second determining unit is used to determine the optimal time for reservoir to switch to steam drive based on the relationship diagram between oil saturation and reservoir thermal utilization rate.

[0034] In the above scheme, the first determining unit is specifically used for:

[0035] The heat utilization rate of the oil reservoir for each target well group is determined based on the heat storage of the oil reservoir.

[0036] Curve fitting was performed on the oil reservoir thermal utilization rate and oil saturation of each target well group to obtain a graph showing the relationship between oil saturation and oil reservoir thermal utilization rate.

[0037] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the method described in any of the first aspects.

[0038] A fourth aspect of the present invention provides a computer device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the steps of the method described in any of the first aspects.

[0039] This invention provides a method, apparatus, and equipment for determining the timing of reservoir conversion to steam drive based on oil saturation. The method includes: acquiring production data of multiple target well groups during steam injection; determining the oil saturation of each target well group based on the production data; determining the heat storage of the oil layer when injecting the same amount of steam at different historical production times for each target well group; determining the relationship between oil saturation and oil layer thermal utilization rate based on the heat storage of each oil layer; and determining the optimal timing for reservoir conversion to steam drive based on the relationship between oil saturation and oil layer thermal utilization rate. Thus, this invention studies the oil layer thermal utilization rate under different oil saturation conditions during steam injection of various types of oil wells, fits different oil saturation levels and oil layer thermal utilization rates, and derives the critical oil saturation value required for reservoir conversion to steam drive based on the fitted relationship diagram. This quantifies the timing of conversion based on oil saturation, and ultimately determines the optimal timing for reservoir conversion to steam drive based on the remaining saturation of the reservoir, thereby improving the accuracy of determining the timing of steam drive and ultimately improving the overall development effect of the oilfield. Attached Figure Description

[0040] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0041] In the attached diagram:

[0042] Figure 1 A schematic flowchart of a method for determining reservoir shifting timing based on oil saturation according to an embodiment of the present invention is shown.

[0043] Figure 2 A graph showing oil saturation and heat storage of the oil layer according to an embodiment of the present invention is shown;

[0044] Figure 3 The temperature field and gas cavity expansion diagram of a target well group with an oil saturation of 40% according to an embodiment of the present invention are shown.

[0045] Figure 4 The temperature field and gas cavity expansion diagram of a target well group with an oil saturation of 70% are shown according to an embodiment of the present invention.

[0046] Figure 5A graph showing the relationship between oil saturation and reservoir thermal efficiency according to an embodiment of the present invention is shown.

[0047] Figure 6 A schematic diagram of an apparatus for determining reservoir shifting timing based on oil saturation according to an embodiment of the present invention is shown.

[0048] Figure 7 A schematic diagram of a computer device structure according to an embodiment of the present invention is shown;

[0049] Figure 8 A schematic diagram of a computer-readable storage medium structure according to an embodiment of the present invention is shown. Detailed Implementation

[0050] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0051] To better understand the technical solution of this invention, the steam huff and puff technology will be introduced first.

[0052] Steam injection is the most commonly used method in heavy oil extraction and the best-performing thermal recovery method in industrial applications. Steam injection, also known as steam-induced or circulating steam injection, involves injecting a certain amount of steam into the well, shutting it in for a period of time, and then reopening the well to resume production. The steam injection process can be divided into three stages: steam injection, well shut-in, and recovery.

[0053] For heavy oil huff and puff development, during steam injection, the production zone in the well has permeability. Therefore, when high-pressure steam enters the oil layer, the oil layer absorbs the heat from the steam through its own steam absorption capacity, resulting in the following situation:

[0054] 1. Increased oil reservoir temperature reduces crude oil viscosity. While both oil and water viscosities decrease with increasing reservoir temperature, the decrease in water viscosity is much less pronounced than that of oil, thus improving the oil-water mobility ratio.

[0055] 2. As the temperature of the oil layer increases, the oil expands, its saturation increases, and it becomes more fluid.

[0056] 3. The steam injected into the oil layer has a distillation effect, which can lower the boiling point of the reservoir liquid, but it can also cause the oil to be eroded.

[0057] However, due to the significant differences in reservoir permeability, the direction and extent of steam propagation within the reservoir are uncertain, leading to various development challenges during subsequent steam huff and puff development. First, inter-layer conflicts are prominent. High-permeability reservoirs have a high steam absorption capacity, and the steam front selectively enters these reservoirs, preventing low-permeability reservoirs from absorbing steam and resulting in some vertically unusable reservoirs. This leads to uneven planar heating and increased directional effects of steam drive. Second, for the same reason, high-permeability areas exhibit significant steam wave propagation effects, while low-permeability areas are not reached by steam waves and lack heat transfer. Therefore, influenced by the planar wave effect of the steam flow field, the utilization rate of the same reservoir layer will also be significantly uneven. In the later stages of steam huff and puff, the fingering of steam along high-permeability layers and its overlapping at the top of the reservoir worsens both the crude oil recovery effect and economic benefits.

[0058] Furthermore, during the thermal recovery of heavy oil, as the amount of crude oil produced near the wellbore increases, a funnel-shaped cavity gradually appears. As steam injection progresses, the funnel-shaped cavity extends further out, resulting in increasingly poor recovery efficiency and eventually leading to an economic limit. When the economic limit is reached, characteristics such as a faster rate of decline in crude oil production, a decrease in the oil production rate, a decrease in the production-injection ratio, a deterioration in development effectiveness, and a decline in economic benefits will emerge.

[0059] When steam injection development reaches its economic limit, the development effect needs to be analyzed and evaluated to determine whether to proceed to tertiary oil recovery, i.e., whether to enter the steam drive stage. However, converting an oil reservoir to steam drive involves the establishment of a well network, the construction of surface engineering, and the completion of supporting oil production engineering, making it a massive undertaking. Therefore, before the conversion, a precise assessment of economic benefits and production is necessary to determine the optimal time to enter the steam drive stage, ensuring that the reservoir recovery rate and economic benefits indicators are met during the steam drive phase.

[0060] Based on this, the present invention provides a method for determining the timing of reservoir transition based on oil saturation, such as... Figure 1 As shown, the method includes the following steps:

[0061] S110, acquire production data of multiple target well groups during the steam injection process;

[0062] First, multiple target well groups within the extra-heavy oil block are selected. These target well groups are generally those with good well conditions, well-developed well networks, and continuous production. Then, production data from the steam injection process of these target well groups is acquired. This production data includes: production rate, temperature, and perforation parameters. Perforation is primarily the process of ejecting material through the casing and cement sheath to create channels within the rock mass, establishing a connection between the formation and the wellbore to facilitate the entry of reservoir fluids into the wellbore. Perforation parameters include: perforation depth, perforation spring phase, hole diameter, and hole density.

[0063] Generally, each target well group may contain multiple production wells. When obtaining production data of the target well group during the steam huff and puff process, it is necessary to statistically analyze the production data of all production wells in each target well group, and then use the sum of the production data of each production well as the production data of the target well group.

[0064] S111, Determine the oil saturation of each target well group based on the production data;

[0065] In one implementation, determining the oil saturation of a target well group based on the production data includes:

[0066] The production of the target well group is divided into different producing layers based on the perforation parameters;

[0067] Determine the extraction rate for each producing layer;

[0068] The remaining oil saturation of each production layer is determined based on the original oil saturation of the production layer and the recovery rate of each production layer.

[0069] The target producing layer of the target well group is determined, and the remaining oil saturation of the target producing layer is determined based on the remaining oil saturation of each producing layer; the remaining oil saturation of the target producing layer is the oil saturation of the target well group.

[0070] It is understandable that an oil reservoir contains many producing layers, each with different permeability. Therefore, after obtaining production data, the production can be divided into different producing layers based on perforation data, so that each producing layer corresponds to a production rate. For each producing layer, the corresponding reserves can be calculated based on the layer area and thickness, and the recovery rate (recovery percentage) of each producing layer can be determined based on the reserves.

[0071] Specifically, the recovery rate of each production layer can be determined using the formula: Cumulative oil production / Reserves * 100%, where the cumulative oil production of each production layer is the output of that production layer.

[0072] Then, the remaining saturation of each production layer is determined according to the formula: Remaining oil saturation = Original oil saturation × (1 - Recovery level). The original oil saturation of each production layer can be obtained in advance.

[0073] It should be noted that, due to the varying connectivity of each production layer, layers with good connectivity experience better steam cavity expansion after steam injection, which significantly improves oil production. Therefore, the target production layer for each target well group is a layer with high connectivity, such as a layer with connectivity greater than 70%.

[0074] S112, determine the heat storage of the oil layer when the same amount of steam is injected into each of the target well groups at different historical production times;

[0075] Once the oil saturation of each target well group is determined, it is equivalent to identifying multiple different types of oil saturation. This invention further needs to determine the changes in oil saturation and reservoir heat storage under the same injected heat (same steam injection rate).

[0076] In one implementation, determining the heat storage of the oil reservoir when the same amount of steam is injected into each target well group at different historical production times includes:

[0077] For any historical mining time, the heat content of the injected oil layer of each target well group is determined based on the steam injection volume, and the heat produced by each target well group is determined based on the produced fluid temperature.

[0078] The heat storage of the oil layer is determined based on the heat content of the injected oil layer and the heat produced; the heat storage of the oil layer is the difference between the heat content of the injected oil layer and the heat produced.

[0079] In one embodiment, determining the heat content of the injected reservoir in each target well group based on the steam injection rate includes:

[0080] The total injected heat is determined based on the gas injection volume;

[0081] The heat loss along the steam injection path is determined based on the temperature change of the steam.

[0082] The injected oil layer heat content of the target well group is determined based on the total injected heat and heat loss. The injected oil layer heat content is the difference between the total injected heat and the heat loss.

[0083] Specifically, for any target well group, this embodiment of the invention can obtain injection data and production data for each historical mining time (over the years, such as 15 years), and then obtain the gas injection volume based on the injection data and determine the production fluid temperature based on the production data.

[0084] Then, the heat content of the injected oil layer in each target well group is calculated based on the steam injection rate, and the heat output of each target well group is calculated based on the production fluid temperature. The difference between the heat content of the injected oil layer and the heat output is the heat storage of the oil layer.

[0085] Since steam loses heat along the way when entering the oil layer, the amount of heat loss along the way must be removed when determining the heat content of the injected oil layer based on the injection volume.

[0086] Once the injected oil layer heat content and produced heat of each target well group over the years are determined, it is equivalent to determining the corresponding oil layer heat storage under various oil saturation levels. Then, an oil saturation and oil layer heat storage chart can be fitted, and the relationship between oil saturation and oil layer heat storage can be seen intuitively from the oil saturation and oil layer heat storage chart.

[0087] For example, refer to Figure 2Assuming two target well groups, A and B, with oil saturation of 40% for well group A and 70% for well group B, and using injection and production data over a 15-year period, determine the annual heat production and total injected heat for both target well groups from 2008 to 2022. Since the gas injection rate is the same for both well groups, the total injected heat is also the same, which is: Figure 2 Marker 21 in the text.

[0088] The final determined heat production curves for target well group A over a 15-year period are shown in label 22, and the heat production curves for target well group B over a 15-year period are shown in label 23. The difference between labels 21 and 22 represents the reservoir heat storage of target well group A; the difference between labels 21 and 23 represents the reservoir heat storage of target well group B.

[0089] from Figure 2 As can be seen, the heat storage in the oil layer of target well group B with an oil saturation of 70% is significantly higher than that of target well group A with an oil saturation of 40%, indicating that under the same heat injection, the higher the oil saturation, the more heat is stored in the oil layer.

[0090] Furthermore, in order to further verify that the higher the oil saturation, the more heat is stored in the oil layer, the present invention can also analyze the temperature field development and gas cavity expansion at different oil saturations through numerical simulation under the condition of fixed injection volume and liquid production volume.

[0091] Continuing with the example of target well groups A and B, after determining the heat content of the injected oil layers in target well groups A and B, simulations were performed under constant steam injection and fluid production rates, taking into account the heat content of the injected oil layers in target well groups A and B. The resulting temperature field and steam cavity expansion diagrams for target well groups A and B are shown below. Figure 3 As shown, the temperature field and gas cavity expansion diagram of target well group B are as follows. Figure 4 As shown.

[0092] from Figure 3 and Figure 4 ( Figure 3 and Figure 4 (The values ​​on the right side represent temperature; different colors represent different temperatures.) It can be seen that one steam injection well provides steam to nine production wells, under constant injection and production rates. Figure 4 The target well group B, with an oil saturation of 70%, shows a well-developed temperature field. Figure 4 The darker areas are larger (and at higher temperatures), and the steam cavity expands more noticeably; while Figure 3The temperature field development and gas cavity expansion effect of target well group A with an oil saturation of 40% are shown to be the second best. This also directly proves that under the same heat injection, the higher the oil saturation, the more heat is stored in the oil layer.

[0093] S113, Determine the relationship between oil saturation and oil layer thermal utilization rate based on the heat storage of each oil layer;

[0094] In one embodiment, determining the relationship between oil saturation and oil layer thermal utilization rate based on the heat storage of each oil layer includes:

[0095] The reservoir heat utilization rate of each target well group is determined based on the reservoir heat storage.

[0096] Curve fitting was performed on the reservoir thermal utilization rate and oil saturation of each target well group to obtain the relationship between oil saturation and reservoir thermal utilization rate.

[0097] Specifically, once the heat storage of the oil reservoir in each target well group is determined, the heat utilization rate of the oil reservoir for each target well group can be determined based on the heat storage of the oil reservoir. The heat utilization rate of the oil reservoir is calculated as: Heat storage of the oil reservoir / Heat content of the injected oil reservoir.

[0098] Since the target well group in this embodiment has various oil saturation levels, such as 20%, 35%, 38%, 45%, 47%, 50%, 53%, 56%, 58%, 66%, 70%, etc., and each oil saturation level corresponds to a reservoir thermal utilization rate, curve fitting can be performed on all oil saturations and their corresponding reservoir thermal utilization rates to determine the relationship between oil saturation and reservoir thermal utilization rate.

[0099] The relationship between oil saturation and reservoir thermal efficiency can be found in the diagram. Figure 5 .

[0100] S114, Determine the optimal time for reservoir to switch to steam drive based on the relationship diagram between oil saturation and reservoir thermal utilization rate.

[0101] from Figure 5 As can be seen, when the oil saturation is below the critical value, the thermal efficiency of the oil layer remains almost unchanged as the oil saturation increases; however, when the oil saturation is above the critical value, the thermal efficiency of the oil layer gradually increases.

[0102] Based on this, in one embodiment, the optimal timing for reservoir conversion to steam drive is determined according to the relationship diagram between oil saturation and reservoir thermal utilization rate, including:

[0103] The inflection point detection function is used to detect the inflection point in the relationship between oil saturation and reservoir thermal utilization rate, and the inflection point in the relationship between oil saturation and reservoir thermal utilization rate is obtained.

[0104] The oil saturation corresponding to the inflection point is determined as the target oil saturation.

[0105] The optimal timing for switching from reservoir to steam drive is determined based on the target oil saturation. The optimal timing is the moment when the remaining oil saturation of the reservoir is equal to the target oil saturation.

[0106] from Figure 5 It can be seen that when the oil saturation is greater than 40%, the heat utilization rate of the oil layer also increases with the increase of oil saturation; when the oil saturation is less than 40%, the heat utilization rate of the oil layer hardly changes with the increase of oil saturation, that is, 40% is the turning point.

[0107] Therefore, when using the inflection point detection function to detect the inflection point of the relationship between oil saturation and reservoir thermal utilization rate, it can be determined that 40% is the inflection point of oil saturation. The target oil saturation is 40%, and the optimal time to switch to steam drive is the moment when the remaining oil saturation of the reservoir is 40%.

[0108] In practical applications, the remaining oil saturation of a well group can be measured. When the remaining oil saturation of a well group is determined to be 40%, this is the optimal time to switch to steam drive.

[0109] This invention studies the reservoir thermal utilization rate under different oil saturation conditions during steam injection in various types of oil wells. It fits different oil saturation levels and reservoir thermal utilization rates, and derives the critical oil saturation value required for reservoir conversion to steam drive based on the fitted relationship graph. Finally, it accurately determines the optimal timing for reservoir conversion to steam drive based on the critical residual saturation value, thereby ensuring the accuracy of the conversion timing and improving the overall development effect of the oilfield.

[0110] Based on the same inventive concept as in the foregoing embodiments, this embodiment also provides a device for determining the timing of reservoir shifting based on oil saturation, such as... Figure 6 As shown, the device includes:

[0111] Acquisition unit 61 is used to acquire production data of multiple target well groups during the steam injection process;

[0112] The first determining unit 62 is used to determine the oil saturation of each target well group based on the production data; determine the heat storage of the oil layer when the same amount of steam is injected into each target well group at different historical mining times; and determine the relationship between oil saturation and oil layer heat utilization rate based on the heat storage of each oil layer.

[0113] The second determining unit 63 is used to determine the optimal time for reservoir to switch to steam drive based on the relationship diagram between oil saturation and reservoir thermal utilization rate.

[0114] In one embodiment, the first determining unit 62 is specifically used for:

[0115] The heat utilization rate of the oil reservoir for each target well group is determined based on the heat storage of the oil reservoir.

[0116] Curve fitting was performed on the oil reservoir thermal utilization rate and oil saturation of each target well group to obtain a graph showing the relationship between oil saturation and oil reservoir thermal utilization rate.

[0117] Since the apparatus described in the embodiments of this invention is used to implement the method for determining reservoir shifting timing based on oil saturation, those skilled in the art can understand the specific structure and variations of this apparatus based on the method described in the embodiments of this invention, and therefore will not be repeated here. All apparatuses used in the methods of the embodiments of this invention fall within the scope of protection of this invention.

[0118] Based on the same inventive concept, this embodiment provides a computer device 700, such as... Figure 7 As shown, it includes a memory 710, a processor 720, and a computer program 711 stored in the memory 710 and executable on the processor 720. When the processor 720 executes the computer program 711, it implements any step of the method described above.

[0119] Based on the same inventive concept, this embodiment provides a computer-readable storage medium 800, such as... Figure 7 As shown, a computer program 811 is stored thereon, which, when executed by a processor, implements the steps of any of the methods described above.

[0120] Through one or more embodiments of the present invention, the present invention has the following beneficial effects or advantages:

[0121] This invention provides a method, apparatus, and equipment for determining the timing of reservoir conversion to steam drive based on oil saturation. The method includes: acquiring production data of multiple target well groups during steam injection; determining the oil saturation of each target well group based on the production data; determining the heat storage of the reservoir when the same amount of steam is injected at different historical production times for each target well group; determining the relationship between oil saturation and reservoir thermal utilization rate based on the heat storage of each reservoir; and determining the optimal timing for reservoir conversion to steam drive based on the relationship between oil saturation and reservoir thermal utilization rate. Thus, this invention studies the reservoir thermal utilization rate under different oil saturation conditions during steam injection of various types of oil wells, fits different oil saturation levels and reservoir thermal utilization rates, derives the critical oil saturation value required for reservoir conversion to steam drive based on the fitted relationship graph, and finally determines the optimal timing for reservoir conversion to steam drive based on the critical residual saturation value, thereby improving the accuracy of determining the timing of steam drive conversion and thus improving the overall development effect of the oilfield.

[0122] The algorithms and displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general-purpose systems can also be used in conjunction with the teachings herein. The required structure for constructing such systems is apparent from the above description. Furthermore, this invention is not directed to any particular programming language. It should be understood that the contents of the invention described herein can be implemented using various programming languages, and the above description of specific languages ​​is for the purpose of disclosing the best mode of implementation of the invention.

[0123] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0124] Similarly, it should be understood that, in order to simplify this disclosure and aid in understanding one or more of the various aspects of the invention, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, this method of disclosure should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into this detailed description, wherein each claim itself is a separate embodiment of the invention.

[0125] Those skilled in the art will understand that modules in the device of the embodiments can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiments can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components. Except where at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or device so disclosed. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0126] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0127] The various component embodiments of the present invention can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some or all of the components of the gateway, proxy server, or system according to embodiments of the present invention. The present invention can also be implemented as a device or apparatus program (e.g., a computer program and computer program product) for performing some or all of the methods described herein. Such programs implementing the present invention can be stored on a computer-readable medium or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0128] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0129] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0130] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for determining the timing of reservoir conversion and displacement based on oil saturation, characterized in that, The method includes: Acquire production data from multiple target well groups during the steam injection process; The oil saturation of each target well group is determined based on the production data; the remaining oil saturation of the target producing layer in the target well group is the oil saturation of the target well group. Determine the heat storage of the oil reservoir when the same amount of steam is injected into each of the target well groups at different historical production times; A graph showing the relationship between oil saturation and oil layer thermal utilization rate is determined based on the heat storage of each oil layer. The optimal timing for switching to steam drive in the reservoir is determined based on the relationship diagram between oil saturation and reservoir thermal utilization rate; whereby... Determining the optimal timing for reservoir steam drive based on the relationship between oil saturation and reservoir thermal utilization includes: The inflection point detection function is used to detect the inflection point in the relationship graph between oil saturation and oil reservoir thermal utilization rate, and the inflection point in the relationship graph is obtained. The oil saturation corresponding to the inflection point is determined as the target oil saturation. The optimal timing for switching the reservoir to steam drive is determined based on the target oil saturation. The optimal timing is the time when the remaining oil saturation of the reservoir is the target oil saturation.

2. The method as described in claim 1, characterized in that, The production data includes: production rate, temperature, and perforation parameters; determining the oil saturation of the target well group based on the production data includes: The production of the target well group is divided into different producing layers according to the perforation parameters; Determine the extraction rate for each producing layer; The remaining oil saturation of each production layer is determined based on the original oil saturation of the production layer and the recovery rate of each production layer; The target producing layer of the target well group is determined, and the remaining oil saturation of the target producing layer is determined based on the remaining oil saturation of each producing layer.

3. The method as described in claim 1, characterized in that, Determining the heat storage of the oil reservoir when the same amount of steam is injected into each of the target well groups at different historical production times includes: For any historical mining time, the heat content of the injected oil layer of each target well group is determined based on the steam injection volume, and the heat produced by each target well group is determined based on the produced fluid temperature. The heat storage of the oil layer is determined based on the heat content of the injected oil layer and the heat generated; the heat storage of the oil layer is the difference between the heat content of the injected oil layer and the heat generated.

4. The method as described in claim 3, characterized in that, The step of determining the injected reservoir heat content of each target well group based on the steam injection volume includes: The total injected heat is determined based on the steam injection volume; The heat loss along the steam injection path is determined based on the temperature change of the steam. The injected oil layer heat content of the target well group is determined based on the total injected heat and the heat loss, wherein the injected oil layer heat content is the difference between the total injected heat and the heat loss.

5. The method as described in claim 1, characterized in that, The method for determining the relationship between oil saturation and oil reservoir thermal utilization rate based on the heat storage of the oil reservoir includes: The heat utilization rate of the oil reservoir for each target well group is determined based on the heat storage of the oil reservoir. Curve fitting was performed on the oil reservoir thermal utilization rate and oil saturation of each target well group to obtain a graph showing the relationship between oil saturation and oil reservoir thermal utilization rate.

6. A device for determining reservoir shifting timing based on oil saturation, characterized in that, The device includes: The acquisition unit is used to acquire production data of multiple target well groups during the steam injection process. The first determining unit is used to determine the oil saturation of each target well group based on the production data; determine the heat storage of the oil layer when the same amount of steam is injected at different historical production times for each target well group; determine the relationship between oil saturation and oil layer heat utilization rate based on the heat storage of each oil layer; and the remaining oil saturation of the target producing layer of the target well group is the oil saturation of the target well group. The second determining unit is used to determine the optimal timing for switching the reservoir to steam drive based on the relationship diagram between the oil saturation and the thermal utilization rate of the oil layer. Determining the optimal timing for reservoir steam drive based on the relationship between oil saturation and reservoir thermal utilization includes: The inflection point detection function is used to detect the inflection point in the relationship graph between oil saturation and oil reservoir thermal utilization rate, and the inflection point in the relationship graph is obtained. The oil saturation corresponding to the inflection point is determined as the target oil saturation. The optimal timing for switching the reservoir to steam drive is determined based on the target oil saturation. The optimal timing is the time when the remaining oil saturation of the reservoir is the target oil saturation.

7. The apparatus as claimed in claim 6, characterized in that, The first determining unit is specifically used for: The heat utilization rate of the oil reservoir for each target well group is determined based on the heat storage of the oil reservoir. Curve fitting was performed on the oil reservoir thermal utilization rate and oil saturation of each target well group to obtain a graph showing the relationship between oil saturation and oil reservoir thermal utilization rate.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method according to any one of claims 1-5.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the method according to any one of claims 1-5.

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