Method, device and equipment for determining effective use pressure of multi-layer oil reservoir and medium

Abstract

The invention relates to the technical field of oil and gas field development, and discloses a method, a device, equipment and a medium for determining effective use pressure of a multilayer oil reservoir. Monitoring and recording the split-flow rate and the injection pressure in a water-oil displacement experiment and a plurality of chemical oil displacement experiments of the multi-layer parallel core oil displacement experiment, determining the dimensionless effective use pressure of each core sample on the laboratory scale, and calculating the flow rate of each core sample according to the dimensionless effective use pressure of each core sample on the laboratory scale. The dimensionless effective use pressure of the small layer on the mine field scale is determined, and the number of relevant indexes of discharged liquid is enriched.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development, and in particular to a method, device, equipment and medium for determining the effective producing pressure of a multi-layer oil reservoir. Background Art

[0002] With the development of science and technology, oil and gas field development technology continues to improve.

[0003] In the process of oil and gas field development, relevant technologies can be used to drive the reservoir to produce liquid and realize oil and gas production by water flooding and chemical flooding. Water flooding is to maintain the formation pressure and displace crude oil by injecting water, while chemical flooding is to improve the efficiency of oil recovery by injecting chemical agents.

[0004] The determination of the relevant indicators of liquid discharge during water flooding and chemical flooding in oil reservoirs by related technologies is helpful to improve the efficiency of oil and gas development. However, the relevant indicators currently determined by related technologies are relatively few. Summary of the invention

[0005] The present invention provides a method, device, equipment and medium for determining the effective producing pressure of a multi-layer oil reservoir, which is used to solve the defect of the related technology that there are few reservoir fluid production related indicators, realize the determination of the dimensionless effective producing pressure of small and medium layers in the combined production interval at the mine scale, and enrich the number of fluid production related indicators.

[0006] In a first aspect, the present invention provides a method for determining effective producing pressure of a multi-layer oil reservoir, comprising:

[0007] Conducting a multi-layer parallel core flooding experiment on a plurality of core samples corresponding to a plurality of small layers in a commingled production interval of a typical well group; wherein the multi-layer parallel core flooding experiment includes a water flooding experiment and a plurality of chemical flooding experiments conducted in sequence, and different chemical agents are used in each of the chemical flooding experiments;

[0008] When it is monitored that the comprehensive water content of the multiple core samples in the water flooding experiment reaches the target water content, the water flooding pressure and the first diversion rate of each core sample are recorded respectively; wherein the target water content is the water content of the commingled production interval at the end of the water flooding of the commingled production interval;

[0009] When it is monitored that the second diversion rate of the core sample in the chemical flooding experiment is greater than the first diversion rate of the core sample, the corresponding chemical flooding pressure is recorded, and the ratio of the chemical flooding pressure to the water flooding pressure is determined as the dimensionless effective producing pressure of the core sample in the chemical flooding experiment;

[0010] According to the dimensionless effective producing pressure of each core sample in each chemical flooding experiment, the dimensionless effective producing pressure of each sublayer at the mine field scale is determined.

[0011] Optionally, the fluid viscosity of the chemical agent in each chemical flooding experiment is different; and determining the dimensionless effective producing pressure of each of the small layers at the mine scale according to the dimensionless effective producing pressure of each of the core samples in each of the chemical flooding experiments includes:

[0012] Obtaining the fluid viscosity of the chemical agent in each chemical flooding experiment;

[0013] For any of the core samples, the dimensionless effective producing pressure of the core sample in each of the chemical flooding experiments and each of the fluid viscosities are used to determine the relationship between the dimensionless effective producing pressure of the target sublayer at the mine scale, the fluid viscosity and the inter-well position; the corresponding target dimensionless effective producing pressure is determined based on the inter-well position of the target sublayer in the typical well group, the fluid viscosity of the chemical agent used in the chemical flooding of the typical well group and the relationship; and the target dimensionless effective producing pressure is used as the dimensionless effective producing pressure of the target sublayer at the mine scale.

[0014] Optionally, the relationship between the dimensionless effective producing pressure of the core sample in each chemical flooding experiment and each fluid viscosity is determined at the field scale, the fluid viscosity and the well position, including:

[0015] The relationship is constructed based on the dimensionless effective producing pressure of the core sample in each of the chemical flooding experiments, the viscosity of each of the fluids, the power-law fluid viscosity model, the core equivalent shear rate model and the radial flow velocity distribution model.

[0016] Optionally, after taking the target dimensionless effective producing pressure as the dimensionless effective producing pressure of the target sub-layer at the mine scale, the method further comprises:

[0017] Acquire a first injection pressure when water flooding of the target sublayer is completed, and a second injection pressure when chemical flooding of the target sublayer is performed;

[0018] Calculating the product of the dimensionless effective producing pressure of the target sublayer at the mine scale and the first injection pressure, and determining whether the second injection pressure is greater than the product;

[0019] If the second injection pressure is greater than the product, it is determined that the target sublayer is effectively mobilized;

[0020] If the second injection pressure is not greater than the product, it is determined that the target sublayer is not effectively utilized.

[0021] Optionally, before performing the multi-layer parallel core flooding experiment on a plurality of core samples corresponding one-to-one to a plurality of small layers in the commingled production interval of a typical well group, the method further comprises:

[0022] Determine the physical property information of each of the sub-layers in the combined production interval according to the logging information and perforation information of the typical well group;

[0023] According to the physical property information of each sub-layer, the geometric similarity rule and the seepage similarity rule of the core from the mine to the laboratory, the lithology sample corresponding to each sub-layer is produced.

[0024] Optionally, the physical property information of each of the sublayers includes permeability;

[0025] The permeability of each of the sublayers is different, and the permeability of each of the core samples is the same as the corresponding sublayer.

[0026] Optionally, after recording the water drive pressure and respectively recording the first diversion rate of each core sample, the method further comprises:

[0027] If it is determined that the second diversion rate of the highest permeability rock in the chemical oil recovery experiment remains less than the first diversion rate of the highest permeability rock, it is prohibited to determine the dimensionless effective production pressure of the highest permeability rock in the chemical oil recovery experiment; wherein the highest permeability rock is the core sample with the highest permeability among the multiple core samples.

[0028] In a second aspect, the present invention provides a device for determining effective producing pressure of a multi-layer oil reservoir, comprising:

[0029] The experimental unit is used to perform a multi-layer parallel core flooding experiment on a plurality of core samples corresponding to a plurality of small layers in a commingled production interval of a typical well group; wherein the multi-layer parallel core flooding experiment includes a water flooding experiment and a plurality of chemical flooding experiments performed in sequence, and different chemical agents are used in each of the chemical flooding experiments;

[0030] A first recording unit is used for recording the water drive pressure and the first diversion rate of each core sample respectively when it is monitored that the comprehensive water content of the plurality of core samples in the water drive oil experiment reaches the target water content; wherein the target water content is the water content of the commingled production interval when the water drive oil experiment on the commingled production interval ends;

[0031] A second recording unit is used to record the corresponding chemical flooding pressure when it is monitored that the second diversion rate of the core sample in the chemical flooding experiment is greater than the first diversion rate of the core sample;

[0032] A first determining unit is used to determine the ratio of the chemical flooding pressure to the water flooding pressure as the dimensionless effective producing pressure of the core sample in the chemical flooding experiment;

[0033] The second determination unit is used to determine the dimensionless effective producing pressure of each of the sub-layers at the mine scale according to the dimensionless effective producing pressure of each of the core samples in each of the chemical flooding experiments.

[0034] In a third aspect, the present invention provides a computer device comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the method for determining the effective mobilization pressure of a multi-layer oil reservoir according to the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0035] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the method for determining the effective producing pressure of a multilayer oil reservoir according to the first aspect or any corresponding embodiment thereof.

[0036] The present invention provides a method, device, equipment and medium for determining the effective producing pressure of a multi-layer oil reservoir. The present invention can perform a multi-layer parallel core flooding experiment on core samples corresponding to multiple small layers in a combined production interval, and monitor and record the diversion rate and injection pressure in a water flooding experiment and multiple chemical flooding experiments of the multi-layer parallel core flooding experiment, so as to determine the dimensionless effective producing pressure of each core sample on a laboratory scale. According to the dimensionless effective producing pressure of each core sample on a laboratory scale, the dimensionless effective producing pressure of the small layer on a mine scale can be determined, thereby enriching the number of liquid discharge-related indicators. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A flow chart of a method for determining effective producing pressure of a multi-layer oil reservoir provided by an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of a multi-layer parallel core flooding experimental device provided in an embodiment of the present invention;

[0040] Figure 3 A flow chart of another method for determining effective producing pressure of a multi-layer oil reservoir provided by an embodiment of the present invention;

[0041] Figure 4 A schematic diagram of a chemical flooding solution provided in an embodiment of the present invention;

[0042] Figure 5 A schematic diagram of effective producing pressure of a core sample provided by an embodiment of the present invention;

[0043] Figure 6 A dimensionless effective producing pressure chart of each core sample in a chemical flooding experiment provided by an embodiment of the present invention;

[0044] Figure 7 A dimensionless expansion multiple of the wellhead pressure when a small layer is effectively produced provided by an embodiment of the present invention;

[0045] Figure 8 An injection well pressure chart that satisfies the effective utilization of oil layers with different permeabilities under actual conditions of a mine provided by an embodiment of the present invention;

[0046] Fig. 9 A schematic diagram of the structure of a device for determining effective producing pressure of a multi-layer oil reservoir provided by an embodiment of the present invention;

[0047] Fig.10 A schematic diagram of the structure of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Related technologies During water flooding and chemical flooding of a reservoir in an oil reservoir, the water flooding pressure at the end of water flooding can be monitored and determined, and the water flooding pressure can be determined as the starting pressure of the reservoir. The starting pressure is a liquid-related indicator in the oil flooding process, which can be used to determine whether the reservoir has liquid during oil and gas production, which helps to improve oil and gas production efficiency and optimize production plans.

[0050] Related technology During the water drive process of the combined production section, when the water content of the combined production section (the ratio of water production to liquid production in the combined production section) reaches a certain value, the oil production will be very small. At this time, the economic benefits of the mine are not high, and it is necessary to change the production measures and convert the water drive to chemical drive. After the water drive of the small layer is converted to chemical drive, a certain liquid recovery process is required before its liquid output capacity can be restored to the state at the end of water drive. The related technology did not consider the liquid recovery problem when determining the starting pressure of the reservoir. This embodiment will combine the liquid recovery process to determine the liquid recovery pressure of the reservoir after the conversion from water drive to chemical drive, that is, the effective mobilization pressure, to further ensure the efficiency of oil and gas production and optimize the production plan.

[0051] It should also be noted that the effective use of small layers is the purpose of oilfield production and development adjustment and is an evaluation indicator of the effectiveness of chemical measures. The relevant technology only considers whether the chemical system can start the small layer during the injection process, but has never considered the recovery of the liquid production capacity of the small layer, lacks corresponding evaluation indicators, and fails to provide application guidance during mine production. An evaluation method that can cover the start-up pressure gradient of the small layer and the effective use of the small layer is urgently needed.

[0052] Combine the following Figure 1-Figure 8 The method for determining the effective producing pressure of a multi-layer oil reservoir of the present invention is described.

[0053] like Figure 1 As shown, this embodiment proposes a first method for determining the effective producing pressure of a multi-layer oil reservoir, which may include the following steps:

[0054] S101. Conduct multi-layer parallel core flooding experiments on multiple core samples corresponding to multiple small layers in the combined production interval of a typical well group; wherein the multi-layer parallel core flooding experiment includes a water flooding experiment and multiple chemical flooding experiments conducted in sequence, and different chemical agents are used in each chemical flooding experiment.

[0055] The typical well group may include multiple commingled production intervals. The commingled production interval in this embodiment is one of the multiple commingled production intervals of the typical well group. The commingled production interval may include multiple sub-layers.

[0056] Specifically, this embodiment can first obtain the physical property parameters of each sublayer in the combined production interval, and produce a core sample corresponding to each sublayer according to the physical property parameters of each sublayer. Afterwards, this embodiment can perform a multi-layer parallel core flooding experiment on the produced multiple core samples.

[0057] Specifically, in the multi-layer parallel core flooding experiment of this embodiment, each core sample can be vacuumed and saturated with water and oil first. The system temperature is stabilized at the formation temperature by a temperature control system, and aged at the formation temperature for 24 hours, and then a water flooding experiment and multiple chemical flooding experiments are carried out in sequence. It should be noted that in the multiple chemical flooding experiments carried out in this embodiment, different types of chemical agents can be used for oil recovery in each chemical flooding experiment.

[0058] Specifically, this embodiment can use Figure 2 The experimental equipment shown is used to carry out multi-layer parallel core flooding experiments on the above-mentioned multiple core samples. Figure 2 The experimental equipment shown includes oil-water chemical agent piston, valves, pipelines, six-way, core samples, pressure sensors, pumps, beakers and pressure collectors.

[0059] S102. When it is monitored that the comprehensive water content of multiple core samples in the water drive oil experiment reaches the target water content, record the water drive pressure and the first diversion rate of each core sample respectively; wherein the target water content is the water content of the combined production layer at the end of the water drive oil experiment on the combined production layer.

[0060] Specifically, in this embodiment, in a multi-layer parallel core flooding experiment, a water flooding experiment can be performed on multiple core samples, and the comprehensive water content of all core samples in the water flooding experiment can be monitored.

[0061] Among them, the comprehensive water content is the ratio of the water production of all core samples to the liquid production of all core samples.

[0062] The target water content is the water content of the commingled production interval at the end of the water flooding stage of oil and gas production in the commingled production interval of a typical well group. It should be noted that when the commingled production interval is water flooded, after the water content of the commingled production interval reaches a certain value, its oil production is very small and the economic benefits are low. At this time, chemical flooding can be switched to improve the production efficiency. The certain value is the target water content.

[0063] It is understandable that the target moisture content can be set by technical personnel according to the on-site mining conditions, and this embodiment does not limit it. For example, it can be set to a value between 80% and 90%, or a value between 90% and 95%.

[0064] Specifically, the split ratio is the ratio of the liquid production of the core sample to the liquid production of all core samples.

[0065] Specifically, in this embodiment, when the comprehensive water content of all core samples in the water drive oil experiment reaches the target water content at a certain time point, the water drive pressure at that time point, i.e., the pressure applied by the injected water to the core sample, is recorded, and the diversion rate of each core sample at that time point, i.e., the first diversion rate, is recorded respectively. At this point, the water drive oil experiment can be ended in this embodiment.

[0066] S103. When it is monitored that the second diversion rate of the core sample in the chemical flooding experiment is greater than the first diversion rate of the core sample, the corresponding chemical flooding pressure is recorded.

[0067] Specifically, in this embodiment, after the water flooding experiment is completed, multiple chemical flooding experiments can be performed on the multiple core samples in sequence.

[0068] Specifically, in this embodiment, during any chemical flooding experiment, the split rate, i.e., the second split rate, of each core sample in the chemical flooding experiment can be monitored. When it is monitored at a certain time point that the second split rate of any core sample in the chemical flooding experiment is greater than the first split rate of the core sample, the chemical flooding pressure, i.e., the pressure applied by the chemical agent to the core sample at that time point can be recorded.

[0069] It should be noted that, for any core sample, this embodiment can record the chemical flooding pressure at a certain time point when it is monitored that the diversion rate of the core sample in the chemical flooding experiment is greater than the first diversion rate of the core sample.

[0070] It can be understood that when the number of chemical flooding experiments is N, for any core sample, this embodiment can record and obtain N chemical flooding pressures.

[0071] S104. Determine the ratio of the chemical flooding pressure to the water flooding pressure as the dimensionless effective producing pressure of the core sample in the chemical flooding experiment.

[0072] Specifically, in this embodiment, whenever the second diversion rate of the core sample in the chemical flooding experiment is greater than the first diversion rate of the core sample, the chemical flooding pressure at this time is recorded, and the ratio of the chemical flooding pressure to the above-mentioned water flooding pressure is determined, and the ratio is determined as the dimensionless effective producing pressure of the core sample in the chemical flooding experiment, that is, the dimensionless effective producing pressure of the core sample on a laboratory scale.

[0073] It can be understood that this embodiment can obtain the dimensionless effective producing pressure of each core sample in each chemical flooding experiment.

[0074] It should be noted that changes in the injection fluid, injection rate and core permeability combination in water flooding experiments and chemical flooding experiments will affect the injection pressure. The dimensionless effective mobilization pressure is obtained through dimensionless processing, which will help facilitate comparative analysis between different experiments and facilitate conversion to field applications.

[0075] S105. Determine the dimensionless effective producing pressure of each small layer at the mine scale based on the dimensionless effective producing pressure of each core sample in each chemical flooding experiment.

[0076] Among them, the dimensionless effective producing pressure of the small layer at the mine scale is the dimensionless effective producing pressure in the oil and gas exploitation of the small layer.

[0077] Specifically, after determining the dimensionless effective producing pressure of each core sample in each chemical flooding experiment, this embodiment can determine the dimensionless effective producing pressure of each small layer at the mine scale according to the dimensionless effective producing pressure of each core sample in each chemical flooding experiment.

[0078] It should be noted that in oil and gas exploitation, there are differences in water drive development under different reservoir conditions and different construction measures. Determining the dimensionless effective mobilization pressure of small layers at the mine scale will help enhance universality.

[0079] Optionally, in other methods for determining effective producing pressure of multi-layer reservoirs proposed in this embodiment, the fluid viscosity of the chemical agent in each chemical flooding experiment is different. In this case, step S105 may include:

[0080] Obtain the fluid viscosity of the chemical agent in each chemical flooding experiment;

[0081] For any core sample, the relationship between the dimensionless effective producing pressure, fluid viscosity and inter-well position of the target sublayer at the mine scale is determined based on the dimensionless effective producing pressure and each fluid viscosity of the core sample in each chemical flooding experiment. The corresponding target dimensionless effective producing pressure is determined based on the inter-well position of the target sublayer in a typical well group, the fluid viscosity of the chemical agents used in the chemical flooding of the typical well group and the relationship, and the target dimensionless effective producing pressure is used as the dimensionless effective producing pressure of the target sublayer at the mine scale.

[0082] Optionally, the relationship between the dimensionless effective producing pressure, fluid viscosity and well position of the target sublayer at the field scale is determined based on the dimensionless effective producing pressure of the core sample in each chemical flooding experiment and each fluid viscosity, including:

[0083] A relationship is constructed based on the dimensionless effective producing pressure of the core sample in each chemical flooding experiment, the viscosity of each fluid, the power-law fluid viscosity model, the core equivalent shear rate model, and the radial flow velocity distribution model.

[0084] Specifically, this embodiment can determine the fluid viscosity of the chemical agent used in each chemical flooding experiment. This embodiment can use chemical agents with different viscosities to conduct multiple chemical flooding experiments to obtain the effective producing pressure chart indoor experimental results of each core sample under different chemical systems, that is, ξ(μ).

[0085] Specifically, this embodiment can use the power-law fluid viscosity model, the core equivalent shear rate model and the radial flow velocity distribution model to calculate the dimensionless expansion multiple of the mine wellhead pressure under the condition of considering the radial flow, that is, the dimensionless effective mobilization pressure of each small layer at the mine scale.

[0086] Among them, the power-law fluid viscosity model is:

[0087]

[0088] μ is the fluid viscosity, H is the power law coefficient, n is the power law exponent, is the shear rate.

[0089] Among them, the core equivalent shear rate model is:

[0090]

[0091] γ eq The equivalent shear rate, u is the Darcy velocity, k is w is the water phase permeability, S w is the water saturation, is the core porosity, n is the power law exponent, and C is the shear rate correction factor.

[0092] The radial flow velocity distribution model is an infinitely large homogeneous formation with equal thickness. The relationship between the plane radial flow rate / velocity and the radius during fixed production of a single vertical well is:

[0093]

[0094] is the flow rate at time t and radius r, A is the cross-sectional area at radius r, Q is the fixed production, and η is the formation pressure conductivity.

[0095] Using the above three formulas, we can get the relationship between the viscosity of the chemical system and the radius:

[0096]

[0097] Where a and b are both positive constants.

[0098] It should be noted that, for the middle position between wells simulated by the indoor core experiment, the relationship between the viscosity between wells and the viscosity at the wellhead position can be obtained by the above formula:

[0099]

[0100] Where α is the relationship between the effective viscosity of the fluid in the middle of the well and the effective viscosity of the fluid at the wellhead; μ e is the viscosity at the wellhead; μ x Viscosity at the interwell location; r x is the radius of the interwell location from the injection well; r e is the distance radius at the wellhead location.

[0101] From this, we can get the effective viscosity of the chemical at the wellhead:

[0102] μ e =α×μ x .

[0103] The viscosity of the injected fluid changes and affects the injection pressure. By comparing the effective viscosity and the indoor experimental results, the pressure change multiple at the wellhead of the injection end can be obtained, that is, the dimensionless effective production pressure of the small layer at the mine scale:

[0104] β=ξ(μ e ).

[0105] Among them, β is the dimensionless effective producing pressure of the small layer at the mine scale.

[0106] The above formula can be used to determine the relationship between the dimensionless effective producing pressure of the small layer at the mine scale, the fluid viscosity and the inter-well position. This embodiment can solve the dimensionless effective producing pressure at different inter-well positions.

[0107] Specifically, in the method for determining the effective use of the small layer in this embodiment, the ratio of the diversion rate of the small layer before and after chemical flooding can be used as a determination condition. When the ratio is greater than 1, the diversion rate of the small layer after chemical flooding is greater than the diversion rate at the end of water flooding, and the small layer is effectively used. When the ratio is not greater than , the diversion rate of the small layer after chemical flooding is less than the diversion rate at the end of water flooding, and the small layer is affected by the chemical agent and is not effectively used. The data results of the indoor experiment are processed dimensionlessly to obtain the dimensionless effective use pressure.

[0108] Optionally, after step S105, the above method may further include:

[0109] Obtaining a first injection pressure when water flooding of the target sublayer is completed, and a second injection pressure when chemical flooding of the target sublayer is performed;

[0110] Calculate the product of the dimensionless effective producing pressure of the target sublayer at the mine scale and the first injection pressure, and determine whether the second injection pressure is greater than the product;

[0111] If the second injection pressure is greater than the product, it is determined that the target sublayer is effectively utilized;

[0112] If the second injection pressure is not greater than the product, it is determined that the target sublayer is not effectively utilized.

[0113] It should be noted that, in this embodiment, the pressure at the end of water flooding in the small layer during mine production and the production pressure after conversion to chemical flooding can be used to determine the effective utilization of the small layer during mine production.

[0114] When P cfi >β×P wf When , it indicates that the small layer is effectively used. cfi is the production pressure of the sublayer during chemical flooding; P wf is the production pressure at the end of water flooding; β is the dimensionless effective production pressure converted by the mine production scale. Otherwise, it means that the small layer is not effectively produced.

[0115] Specifically, this embodiment can determine whether the sub-layer is effectively produced when oil and gas are produced in the sub-layer based on the dimensionless effective producing pressure of the sub-layer at the mine scale.

[0116] It can be understood that this embodiment can determine the dimensionless effective producing pressure of each small layer in the combined mining interval at the mine scale.

[0117] Specifically, in the method for determining the effective utilization of a mine reservoir, this embodiment can apply the results of indoor experiments to mine production. The power law fluid viscosity model, the core equivalent shear rate model, and the radial flow velocity distribution model are used to determine the dimensionless expansion multiple of the wellhead pressure in the mine radial flow, and then the pressure at the end of the mine water flooding and the pressure after the conversion to chemical flooding are used to determine the effective utilization of the reservoir under mine production conditions.

[0118] It should be noted that this embodiment can determine the startup situation during the existing small layer injection process and upgrade to the effective utilization of the small layer, that is, the small layer is restored to its original liquid production capacity, and the effective utilization of the small layer is determined by using a multi-layer core flooding experiment. In combination with the actual injection-production pressure difference and the production work system on site, the injection well pressure that meets the effective utilization of oil layers with different permeabilities under actual conditions of the mine is given, which provides guidance for the mine injection.

[0119] This embodiment can determine the startup situation during the existing small-layer injection process, and upgrade to the effective utilization of the small layer. It uses a multi-layer core flooding experiment to determine the effective utilization of the small layer, and combines the actual injection-production pressure difference and production work system on site to give the injection well pressure that meets the effective utilization of oil layers with different permeabilities under actual conditions of the mine.

[0120] The method for determining the effective producing pressure of a multi-layer reservoir proposed in this embodiment can carry out a multi-layer parallel core flooding experiment on core samples corresponding to multiple small layers in a combined production interval, and monitor and record the diversion rate and injection pressure in the water flooding experiment and multiple chemical flooding experiments of the multi-layer parallel core flooding experiment, so as to determine the dimensionless effective producing pressure of each core sample at the laboratory scale. Based on the dimensionless effective producing pressure of each core sample at the laboratory scale, the dimensionless effective producing pressure of the small layer at the mine scale can be determined, thereby enriching the number of liquid-related indicators.

[0121] based on Figure 1 This embodiment proposes a second method for determining the effective producing pressure of a multi-layer oil reservoir. Before step S101, the method may further include:

[0122] Based on the logging information and perforation information of typical well groups, determine the physical property information of each small layer in the combined production interval;

[0123] According to the physical property information of each small layer, the geometric similarity rules and seepage similarity rules of the core from the mine to the laboratory, the corresponding lithology samples of each small layer are made.

[0124] Specifically, this embodiment can carry out effective production limit research of each layer of multi-layer reservoir for typical well groups in oil fields, and collect logging information of typical well groups. Optionally, the logging information of typical well groups includes depth, acoustic time difference, well diameter, compensated neutron, density, natural gamma, micro-lateral resistivity, shallow lateral resistivity, natural point position, vertical depth, effective porosity, water saturation, fluid type, lithofacies, permeability, mud content, net-to-gross ratio, absolute permeability, current porosity, pressure and oil saturation. Afterwards, this embodiment can combine the perforation information to determine the layer physical property information within the combined production layer.

[0125] Specifically, this embodiment can perform statistics, collation and core parameter design of physical property information of typical well groups. Data information includes but is not limited to: small layer depth, thickness, porosity, permeability, lithofacies, shale content, oil saturation, and perforation information; perforation information is used to determine the combined production layer section, reservoir, collation, and calculation of physical property information in the combined production layer section: number of small layers, grade difference, development status, etc.; and the geometric characteristics and physical property parameters of the core are determined using the geometry and seepage similarity criteria from the mine to the indoor experiment.

[0126] Optionally, the physical property information of each sublayer includes permeability. The permeability of each sublayer is different, and the permeability of each core sample is the same as that of the corresponding sublayer.

[0127] Optionally, after step S102, the above method may further include:

[0128] If it is determined that the second diversion rate of the highest permeability rock in the chemical flooding experiment remains less than the first diversion rate of the highest permeability rock, it is prohibited to determine the dimensionless effective producing pressure of the highest permeability rock in the chemical flooding experiment; wherein the highest permeability rock is the core sample with the highest permeability among multiple core samples.

[0129] It should be noted that when performing multi-layer parallel core flooding experiments on multiple core samples, the diversion rate of the highest permeability rock will generally decrease after switching from water flooding to chemical flooding. Therefore, the diversion rate of the highest permeability rock in the chemical flooding experiment is generally lower than its diversion rate in the water flooding experiment, and the second diversion rate of the highest permeability rock in the chemical flooding experiment will not be higher than its first diversion rate in the water flooding experiment, which means that the prerequisite in step S103 cannot be met and step S103 cannot be executed.

[0130] based on Figure 3 This embodiment proposes another method for determining the effective producing pressure of a multi-layer oil reservoir, which includes steps S1, S2, S3, S4, S5, S6 and S7.

[0131] Specifically, this embodiment can collect and organize logging information of typical well groups, use perforation information to determine the combined production section, count the thickness, porosity, permeability and other parameters of each core layer in the combined production section and the development status of the combined production section, design and produce relevant cores, and conduct multi-layer core oil recovery experiments on this; use the comparison between the small layer diversion rate and the water drive diversion rate to determine whether the small layer is effectively utilized, record the effective utilization pressure limit of the small layer, and perform dimensionless processing with the water drive pressure so that it can be applied to chemical drive production in the mine.

[0132] In this embodiment, in step S1, the logging information of typical well groups can be collected and sorted, including the permeability, thickness and porosity of each sublayer in the commingled production interval. The social information of the commingled production layer is determined. The commingled production information is counted to determine the number of layers, grade difference and development status in the commingled production interval.

[0133] In step S2, core preparation and physical property parameter testing can be performed, and core samples can be constructed according to similar criteria of field-indoor experiments.

[0134] In step S3, this embodiment can perform multi-layer parallel core flooding experiments on multiple core samples, which can specifically include vacuuming, water saturation, oil saturation, water flooding to development state, conversion to chemical flooding, conversion to water flooding and data collection.

[0135] In step S4, this embodiment can perform effective mobilization determination of small layers according to the determination conditions. The determination conditions are f wi(c) >f wi(w) , f wi(c) is the second diversion rate of the core sample in the chemical flooding experiment, f wi(w) is the first diversion rate of the core sample in the water flooding experiment.

[0136] In step S5, this embodiment can perform dimensionless processing, and the specific formula is ξ=P i / P w .P i and P w They are the chemical flooding pressure and water flooding pressure recorded in the water flooding experiment and chemical flooding experiment on core samples, respectively.

[0137] In step S6, this embodiment can convert the wellhead pressure based on the power-law fluid viscosity formula, the core equivalent shear rate formula and the radial flow velocity distribution formula. The power-law fluid viscosity formula, the core equivalent shear rate formula and the radial flow velocity distribution formula are the power-law fluid viscosity model, the core equivalent shear rate model and the radial flow velocity distribution model, respectively.

[0138] In step S7, this embodiment can determine whether the i-th layer is used during oil and gas production. cfi >β×P wf When , the ith sublayer is determined to be used, otherwise it is not used. Where i is the sublayer number except the highest permeability rock.

[0139] Specifically, this embodiment can produce corresponding core samples according to the physical property information of each small layer in the combined mining section. When it is determined that the core permeability combination of each small layer in the combined mining section is 6500×3000×1500×1000×500 millidarcy, the thickness of the small layer is about 9m, and the geometry and seepage similarity rules of the experiment from the mine to the indoor core are used to formulate a 30×3×3 cm core sample. The permeability combination of the core samples corresponding to each small layer is also 6500×3000×1500×1000×500 millidarcy.

[0140] Specifically, in this embodiment, in the multi-layer parallel core flooding experiment on the core sample, the following can be used: Figure 4 The chemical flooding scheme shown in the figure is used to conduct chemical flooding experiments on core samples. Figure 4 The effective producing pressure of each core sample determined by the scheme is as follows: Figure 5In the experiment, the injection pressure P1 at the end of water flooding can be recorded, as well as the diversion rates F2, F3, F4, and F5 of each core sample except the highest permeability rock. After the chemical flooding, when the diversion rate of the small layer is greater than the diversion rate of water flooding, the injection pressure P2, P3, P4, and P5 are recorded at this time. This is the effective production pressure of the small layer.

[0141] Afterwards, if Figure 6 As shown, this embodiment can determine the dimensionless effective producing pressure chart of each core sample except the highest permeability rock in the chemical flooding experiment.

[0142] It should be noted that the indoor core experiment simulates the production state at the end of water flooding at a location 100m away from the wellhead. Based on the dimensionless production pressure map obtained from the indoor experimental test, the dimensionless expansion multiple of the wellhead pressure when the small layer is effectively produced is determined, such as Figure 7 shown.

[0143] like Figure 8 As shown, combined with the actual injection-production pressure difference and production work system on site, the injection well pressure that meets the effective production of oil layers with different permeability under actual conditions of the mine is given.

[0144] This embodiment not only takes into account the starting pressure of the small layer, that is, the injection pressure at which the diversion rate of the small layer is greater than zero, but also takes into account the effective use of the small layer, that is, when the diversion rate of the small layer is restored to the diversion rate during the original water drive, the small layer is effectively used. The use of layers with different permeability can be determined during the implementation of mine production.

[0145] This embodiment provides a method for determining the effective use of small layers in the process of multi-layer oil reservoir polymer injection. Specifically, starting from geological logging information, using similarity criteria combined with indoor experiments, the accurate determination of the effective use of small layers in the process of multi-layer oil reservoir polymer injection is achieved. This embodiment can overcome the problem that the related technology only considers the start-up of small layers, while considering the influence of interlayer interference on the start-up of small layers and the process of small layers recovering their original flow capacity. It can directly determine whether small layers with different permeabilities are effectively used by injection pressure, which is simple and effective.

[0146] This embodiment can determine the startup situation during the injection and polymerization of small layers in the relevant technology, and upgrade to the problem of effective utilization of small layers. It uses multi-layer core flooding experiments to determine the effective utilization of small layers, and combines the actual injection-production pressure difference and production work system on site to give the injection well pressure that meets the effective utilization of oil layers with different permeabilities under actual conditions of the mine.

[0147] The method for determining the effective production pressure of a multi-layer reservoir proposed in this embodiment not only takes into account the starting pressure gradient of the small layer, but also determines the effective production of the small layer under different viscosity chemical agent systems. It provides a method for determining the effective production of each layer of a multi-layer oil layer based on indoor experiments, realizes the characterization of the starting pressure gradient and effective production of the small layer, is easy to operate, and has accurate calculations. It can be used to determine the effective production of small layers with different permeabilities during chemical flooding in mines.

[0148] like Fig. 9 As shown, this embodiment proposes a method for determining the effective producing pressure of a multi-layer oil reservoir, and the device may include:

[0149] Experimental unit 901 is used to perform multi-layer parallel core flooding experiments on multiple core samples corresponding to multiple small layers in the commingled production interval of a typical well group; wherein the multi-layer parallel core flooding experiment includes a water flooding experiment and multiple chemical flooding experiments performed in sequence, and different chemical agents are used in each chemical flooding experiment;

[0150] The first recording unit 902 is used to record the water drive pressure and the first diversion rate of each core sample respectively when the comprehensive water content of the multiple core samples in the water drive oil experiment reaches the target water content; wherein the target water content is the water content of the commingled production layer at the end of the water drive oil experiment on the commingled production layer;

[0151] The second recording unit 903 is used to record the corresponding chemical flooding pressure when it is monitored that the second diversion rate of the core sample in the chemical flooding experiment is greater than the first diversion rate of the core sample;

[0152] A first determining unit 904 is used to determine the ratio of the chemical flooding pressure to the water flooding pressure as the dimensionless effective producing pressure of the core sample in the chemical flooding experiment;

[0153] The second determining unit 905 is used to determine the dimensionless effective producing pressure of each small layer at the mine scale according to the dimensionless effective producing pressure of each core sample in each chemical flooding experiment.

[0154] It should be noted that the processing of the experimental unit 901, the first recording unit 902, the second recording unit 903, the first determining unit 904 and the second determining unit 905 and the beneficial effects thereof can be respectively referred to in Figure 1 Steps S101 to S105 in the above are not described in detail.

[0155] The device for determining the effective producing pressure of a multi-layer reservoir proposed in this embodiment can perform multi-layer parallel core flooding experiments on core samples corresponding to multiple small layers in a combined production interval, and monitor and record the diversion rate and injection pressure in the water flooding experiment and multiple chemical flooding experiments of the multi-layer parallel core flooding experiment, so as to determine the dimensionless effective producing pressure of each core sample at the laboratory scale. Based on the dimensionless effective producing pressure of each core sample at the laboratory scale, the dimensionless effective producing pressure of the small layer at the mine scale can be determined, thereby enriching the number of liquid-related indicators.

[0156] The multi-layer reservoir effective production pressure determination device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0157] The embodiment of the present invention also provides a computer device having the above Fig. 9 The device for determining the effective producing pressure of a multi-layer oil reservoir is shown.

[0158] See also Fig.10 , a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. The various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process instructions executed in the computer device, including instructions stored in or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories. Similarly, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig.10 A processor 10 is taken as an example.

[0159] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0160] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0161] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function. The data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage devices. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0162] The memory 20 may include a volatile memory, such as a random access memory. The memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive. The memory 20 may also include a combination of the above-mentioned types of memory.

[0163] The computer device further comprises a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0164] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0165] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining the effective producing pressure of a multi-layer oil reservoir, characterized in that: include: Conducting a multi-layer parallel core flooding experiment on a plurality of core samples corresponding to a plurality of small layers in a commingled production interval of a typical well group; wherein the multi-layer parallel core flooding experiment includes a water flooding experiment and a plurality of chemical flooding experiments conducted in sequence, and different chemical agents are used in each of the chemical flooding experiments; When it is monitored that the comprehensive water content of the multiple core samples in the water flooding experiment reaches the target water content, the water flooding pressure and the first diversion rate of each core sample are recorded respectively; wherein the target water content is the water content of the commingled production interval at the end of the water flooding of the commingled production interval; When it is monitored that the second diversion rate of the core sample in the chemical flooding experiment is greater than the first diversion rate of the core sample, the corresponding chemical flooding pressure is recorded, and the ratio of the chemical flooding pressure to the water flooding pressure is determined as the dimensionless effective producing pressure of the core sample in the chemical flooding experiment; According to the dimensionless effective producing pressure of each core sample in each chemical flooding experiment, the dimensionless effective producing pressure of each sublayer at the mine field scale is determined.

2. The method according to claim 1, characterized in that The fluid viscosity of the chemical agent in each chemical flooding experiment is different; the dimensionless effective producing pressure of each of the small layers at the mine scale is determined according to the dimensionless effective producing pressure of each of the core samples in each of the chemical flooding experiments, including: Obtaining the fluid viscosity of the chemical agent in each of the chemical flooding experiments; For any of the core samples, the dimensionless effective producing pressure of the core sample in each of the chemical flooding experiments and each of the fluid viscosities are used to determine the relationship between the dimensionless effective producing pressure of the target sublayer at the mine scale, the fluid viscosity and the inter-well position; the corresponding target dimensionless effective producing pressure is determined based on the inter-well position of the target sublayer in the typical well group, the fluid viscosity of the chemical agent used in the chemical flooding of the typical well group and the relationship; and the target dimensionless effective producing pressure is used as the dimensionless effective producing pressure of the target sublayer at the mine scale.

3. The method according to claim 2, characterized in that Determining the relationship between the dimensionless effective producing pressure of the target sublayer at the field scale, the fluid viscosity and the well position according to the dimensionless effective producing pressure of the core sample in each chemical flooding experiment and each fluid viscosity, comprises: The relationship is constructed based on the dimensionless effective producing pressure of the core sample in each of the chemical flooding experiments, the viscosity of each of the fluids, the power-law fluid viscosity model, the core equivalent shear rate model and the radial flow velocity distribution model.

4. The method according to claim 2, characterized in that: After taking the target dimensionless effective producing pressure as the dimensionless effective producing pressure of the target sub-layer at the mine scale, the method further comprises: Acquire a first injection pressure when water flooding of the target sublayer is completed, and a second injection pressure when chemical flooding of the target sublayer is performed; Calculating the product of the dimensionless effective producing pressure of the target sublayer at the mine scale and the first injection pressure, and determining whether the second injection pressure is greater than the product; If the second injection pressure is greater than the product, it is determined that the target sublayer is effectively mobilized; If the second injection pressure is not greater than the product, it is determined that the target sublayer is not effectively utilized.

5. The method according to claim 1, characterized in that Before performing the multi-layer parallel core flooding experiment on a plurality of core samples corresponding one by one to a plurality of small layers in the combined production interval of a typical well group, the method further comprises: Determine the physical property information of each of the sub-layers in the combined production interval according to the logging information and perforation information of the typical well group; According to the physical property information of each sub-layer, the geometric similarity rule and the seepage similarity rule of the core from the mine to the laboratory, the lithology sample corresponding to each sub-layer is produced.

6. The method according to claim 5, characterized in that The physical property information of each of the sublayers includes permeability; The permeability of each of the sublayers is different, and the permeability of each of the core samples is the same as the corresponding sublayer.

7. The method according to claim 6, characterized in that After recording the water drive pressure and respectively recording the first diversion rate of each of the core samples, the method further comprises: If it is determined that the second diversion rate of the highest permeability rock in the chemical oil recovery experiment remains less than the first diversion rate of the highest permeability rock, it is prohibited to determine the dimensionless effective production pressure of the highest permeability rock in the chemical oil recovery experiment; wherein the highest permeability rock is the core sample with the highest permeability among the multiple core samples.

8. A device for determining effective producing pressure of a multi-layer oil reservoir, characterized in that: include: The experimental unit is used to perform a multi-layer parallel core flooding experiment on a plurality of core samples corresponding to a plurality of small layers in a commingled production interval of a typical well group; wherein the multi-layer parallel core flooding experiment includes a water flooding experiment and a plurality of chemical flooding experiments performed in sequence, and different chemical agents are used in each of the chemical flooding experiments; A first recording unit is used for recording the water drive pressure and the first diversion rate of each core sample respectively when it is monitored that the comprehensive water content of the plurality of core samples in the water drive oil experiment reaches the target water content; wherein the target water content is the water content of the commingled production interval when the water drive oil experiment on the commingled production interval ends; A second recording unit is used to record the corresponding chemical flooding pressure when it is monitored that the second diversion rate of the core sample in the chemical flooding experiment is greater than the first diversion rate of the core sample; A first determining unit is used to determine the ratio of the chemical flooding pressure to the water flooding pressure as the dimensionless effective producing pressure of the core sample in the chemical flooding experiment; The second determination unit is used to determine the dimensionless effective producing pressure of each of the sub-layers at the mine scale according to the dimensionless effective producing pressure of each of the core samples in each of the chemical flooding experiments.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for determining the effective producing pressure of a multi-layer oil reservoir as described in any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method for determining the effective producing pressure of a multi-layer oil reservoir according to any one of claims 1 to 7.

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