A method, device and medium for surveying and describing low permeability oil and gas reservoirs

Abstract

The present application discloses a method, device and medium for surveying and describing low permeability oil and gas reservoirs, and relates to the technical field of oil and gas reservoir surveying. The method includes: obtaining historical mining data of low permeability oil and gas reservoirs, dividing the historical mining data according to pre-set data dimensions to obtain multi-dimensional historical data of low permeability oil and gas reservoirs; extracting features from the multi-dimensional historical data to obtain multi-dimensional feature data, inputting the multi-dimensional feature data into a pre-determined low permeability oil layer analysis model, and determining the oil layer value score of the low permeability oil and gas reservoir through the low permeability oil layer analysis model; determining the re-exploitation index of the low permeability oil and gas reservoir according to the oil layer value score, and determining the remaining type of the low permeability oil and gas reservoir according to the re-exploitation index, and determining the re-exploitation plan according to the remaining type. The present application uses multi-dimensional data processing and model construction, combined with the characteristics of low permeability oil and gas reservoirs, to efficiently utilize the remaining value of low permeability oil and gas reservoirs and improve the mining value of oil wells.

Description

Technical Field

[0001] The present application relates to the technical field of oil and gas reservoir exploration, and in particular to a method, equipment and medium for exploring and describing low permeability oil and gas reservoirs. Background Art

[0002] Low permeability oil and gas reservoirs refer to oil and gas reservoirs with low permeability, where oil and gas flow is more difficult. According to the difference in permeability, low permeability oil and gas reservoirs can be divided into different types such as ultra-low permeability, low permeability, medium permeability and high permeability. Low permeability oil and gas reservoirs have the characteristics of poor pressure conductivity, low single well productivity and great development difficulty. Low permeability oil and gas reservoirs usually have smaller porosity and permeability, as well as lower oil-gas ratio and higher viscosity. Due to the rich resources of low permeability oil and gas reservoirs, the development of low permeability oil and gas reservoirs can bring better economic and social benefits.

[0003] Due to the dense lithology, small pore throat and large specific surface area of ​​low permeability reservoirs, the electrochemical effect, microcapillary effect and surface effect on the solid-liquid interface are increased, so it has non-Darcy seepage characteristics. The existence of the starting pressure gradient is more likely to lead to the phenomenon of failure to inject and produce, high pressure near the bottom of the injection well and low pressure near the bottom of the production well. Once the oil well is shut down, it is difficult to start it again, and the damaged oil layer is also difficult to recover. This phenomenon becomes more obvious as the permeability decreases. Summary of the invention

[0004] In order to solve the above problems, the present application proposes a method for surveying and describing low permeability oil and gas reservoirs, including: acquiring historical production data of the low permeability oil and gas reservoirs, dividing the historical production data according to pre-set data dimensions to obtain multi-dimensional historical data of the low permeability oil and gas reservoirs; performing feature extraction on the multi-dimensional historical data to obtain multi-dimensional feature data, inputting the multi-dimensional feature data into a predetermined low permeability oil layer analysis model, and determining the oil layer value score of the low permeability oil and gas reservoir through the low permeability oil layer analysis model; determining the re-exploitation index of the low permeability oil and gas reservoir according to the oil layer value score, and determining the remaining type of the low permeability oil and gas reservoir according to the re-exploitation index, so as to determine the re-exploitation plan according to the remaining type.

[0005] In one example, the method further includes: determining a historical survey type of the low permeability oil and gas reservoir, and determining the data dimension according to the historical survey type, wherein the historical survey type includes but is not limited to physical survey, drilling survey, and logging survey.

[0006] In one example, feature extraction is performed on the multi-dimensional historical data, specifically including: determining feature parameters according to the historical survey type, wherein the feature parameters include but are not limited to porosity and irreducible water saturation; and calculating the permeability of the low permeability oil and gas reservoir according to the feature parameters, wherein the calculation formula of the permeability is:

[0007]

[0008] Wherein, K is the permeability, is the porosity, S is the irreducible water saturation; and the multidimensional characteristic data is determined according to the porosity, the irreducible water saturation and the permeability.

[0009] In one example, the oil layer value score of the low permeability oil and gas reservoir is determined through the low permeability oil layer analysis model, specifically including: determining the production equipment of the low permeability oil and gas reservoir, determining the production parameters of the production equipment according to the characteristic parameters and the permeability, and inputting the production parameters and the multidimensional characteristic data into the low permeability oil layer analysis model; determining the weights corresponding to the multidimensional characteristic data according to the production parameters through the low permeability oil layer analysis model; and determining the oil layer value score according to the weights and the multidimensional characteristic data.

[0010] In one example, before determining the re-exploitation index of the low permeability oil and gas reservoir according to the oil layer value score, the method also includes: determining the environmental parameters of the low permeability oil and gas reservoir, determining the exploitation value threshold of the low permeability oil and gas reservoir according to the environmental parameters and the exploitation parameters, and comparing the oil layer value score with the exploitation value threshold; if the oil layer value score is greater than or equal to the exploitation value threshold, determining the re-exploitation index of the low permeability oil and gas reservoir to continue exploitation; if the oil layer value score is less than the exploitation value threshold, determining the re-exploitation index of the low permeability oil and gas reservoir to not continue exploitation.

[0011] In one example, after determining that the re-exploitation index of the low permeability oil and gas reservoir is to continue exploitation, the method further includes: determining the remaining type of the low permeability oil and gas reservoir according to the environmental parameters and the exploitation parameters, wherein the remaining type includes but is not limited to an uncontrolled well network type, an imperfect injection and production type, a retention type at the top of a thick oil layer, a river channel side zone type, an interlayer interference type, and a retention area type.

[0012] In one example, the method further includes: determining the remaining oil layer distribution characteristics of the low permeability oil and gas reservoir according to the remaining type, and determining the remaining oil layer distribution model of the low permeability oil and gas reservoir according to the remaining oil layer distribution characteristics; and setting a corresponding re-exploitation plan according to the remaining oil layer distribution model.

[0013] In one example, before inputting the multi-dimensional feature data into a predetermined low permeability oil layer analysis model, the method further includes: determining a production case of the low permeability oil and gas reservoir based on the historical production data, and inputting the production case into a neural network model for model training to obtain the low permeability oil layer analysis model.

[0014] On the other hand, the present application also proposes a survey and description device for low permeability oil and gas reservoirs, comprising: at least one processor; and a memory connected to the at least one processor in communication. The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the survey and description device for low permeability oil and gas reservoirs can perform: obtaining historical production data of low permeability oil and gas reservoirs, dividing the historical production data according to pre-set data dimensions to obtain multi-dimensional historical data of the low permeability oil and gas reservoirs; extracting features from the multi-dimensional historical data to obtain multi-dimensional feature data, inputting the multi-dimensional feature data into a pre-determined low permeability oil layer analysis model, and determining the oil layer value score of the low permeability oil and gas reservoir through the low permeability oil layer analysis model; determining the re-production index of the low permeability oil and gas reservoir according to the oil layer value score, and determining the remaining type of the low permeability oil and gas reservoir according to the re-production index, so as to determine the re-production plan according to the remaining type.

[0015] On the other hand, the present application also proposes a non-volatile computer storage medium storing computer executable instructions, wherein the computer executable instructions are configured to: obtain historical production data of a low permeability oil and gas reservoir, divide the historical production data according to preset data dimensions, so as to obtain multi-dimensional historical data of the low permeability oil and gas reservoir; perform feature extraction on the multi-dimensional historical data to obtain multi-dimensional feature data, input the multi-dimensional feature data into a predetermined low permeability oil layer analysis model, and determine the oil layer value score of the low permeability oil and gas reservoir through the low permeability oil layer analysis model; determine the re-production index of the low permeability oil and gas reservoir according to the oil layer value score, and determine the remaining type of the low permeability oil and gas reservoir according to the re-production index, so as to determine the re-production plan according to the remaining type.

[0016] This application uses multi-dimensional data processing and model construction, combined with the characteristics of low-permeability oil and gas reservoirs, to efficiently explore and utilize the residual value of low-permeability oil and gas reservoirs, and rationally develops low-permeability oil and gas reservoirs after oil wells are shut down, allowing oil wells to be put into operation again, thereby increasing the value of oil well extraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0018] Figure 1 A schematic flow chart of a method for surveying and describing a low permeability oil and gas reservoir in an embodiment of the present application;

[0019] Figure 2 This is a schematic diagram of a low permeability oil and gas reservoir survey and description device in an embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0021] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0022] Low permeability reservoirs generally have a small distribution range of sand bodies and poor continuity of oil layers. Therefore, a reasonable arrangement of injection and production wells is the key to the development of low permeability oil fields. Due to the dense lithology, small pore throats and large specific surface area of ​​low permeability reservoirs, the electrochemical effect, microcapillary effect and surface effect on the solid-liquid interface are increased, so they have non-Darcy seepage characteristics. The existence of the starting pressure gradient is more likely to lead to the phenomenon of failure to inject and production, high pressure near the bottom of the injection well and low pressure near the bottom of the production well. Once the oil well is shut down, it is difficult to start it again, and the damaged oil layer is also difficult to recover. This phenomenon becomes more obvious as the permeability decreases. After the oil wells in low permeability reservoirs seep water, they have a great feature: the oil and liquid production indexes drop significantly. Generally, it drops to the lowest when the water content is 50%~60%, and the dimensionless liquid production index is only about 0.4. Under the dual influence of increased water content and low liquid production index, the dimensionless oil production index drops more seriously, only 0.15. This phenomenon is not very obvious in medium and high permeability reservoirs. Even after water breakthrough, the production index and oil recovery index still have an upward trend. There are many reasons for this phenomenon. The preliminary analysis is mainly due to the influence of factors such as wettability, oil-water viscosity ratio, salt sensitivity and water sensitivity of clay minerals. Low permeability reservoirs generally have low underground crude oil viscosity, small oil-water viscosity ratio, hydrophilic rock surface, high bound water saturation, small pore throat, and are more easily blocked by mineral particles. Therefore, the oil-water relative permeability curve of low permeability reservoirs has the following characteristics: with the increase of water saturation, the relative permeability of the water phase rises slowly, while the relative permeability of the oil phase decreases sharply. The relative permeability of the water phase at the residual oil saturation is also small, generally in the range of 0.2~0.4, the two-phase co-permeability point is very low, and the seepage resistance is large. As a result, the liquid production and oil production will be significantly reduced after water breakthrough in the oil well, so it is difficult to maintain stable production by increasing the discharge volume. Low permeability reservoirs are often accompanied by the development of natural or artificial fractures. The key to the successful development of low permeability reservoirs is the understanding and utilization of the fracture system. Fracture systems play a very important role in well network planning, trajectory design, reservoir protection, water injection development, etc. Therefore, the focus of understanding low-permeability reservoirs is not the spatial distribution and changes of matrix permeability, but the spatial distribution and changes of fracture systems. The primary target of reservoir protection is not matrix pore throats, but fracture network systems. In terms of well location, completion methods, trajectory design, water injection development, etc., attention should be paid to the development of fracture network systems.

[0023] like Figure 1 As shown, in order to solve the above problems, an embodiment of the present application provides a method for surveying and describing a low permeability oil and gas reservoir, the method comprising:

[0024] S101. Acquire historical production data of a low permeability oil and gas reservoir, and divide the historical production data according to preset data dimensions to obtain multi-dimensional historical data of the low permeability oil and gas reservoir.

[0025] Low permeability oil and gas reservoirs are generally surveyed by geophysical survey, drilling survey, logging survey and other methods. Among them, geophysical survey uses physical principles to study geophysical fields, and infers the properties of underground rock formations and the existence of oil and gas reservoirs by measuring and interpreting data such as seismic waves, electric fields, and magnetic fields. This technology includes a variety of methods such as seismic exploration, electrical exploration, and magnetic exploration, and has the advantages of low cost, high efficiency, and a wide range of detection. Drilling survey technology is a method of directly obtaining underground core samples. By analyzing core samples, parameters such as lithology, physical properties, and oil content of the formation can be obtained, providing direct evidence for judging the existence and scale of oil and gas reservoirs. This technology has the advantages of high precision and strong reliability, but it is costly and has a long cycle. Well logging exploration technology is a method of measuring physical parameters of formations in boreholes. By analyzing logging data, parameters such as lithology, physical properties, and oil content of the formation can be inferred, providing indirect evidence for judging the existence and scale of oil and gas reservoirs. This technology has the advantages of non-destructive and continuous measurement, but its accuracy and reliability are relatively low. After the low permeability oil and gas reservoirs are surveyed and mined through the above process, there will be residual oil and gas resources in the oil wells, and historical mining data of low permeability oil and gas reservoirs can be obtained. These data may include oil well production data, geological information, rock physical properties, etc. The data can be obtained from the database of the oil and gas company, geological survey reports, and other reliable sources. The acquired data may contain noise, outliers or missing values, and data cleaning is required. This includes removing duplicate data, processing outliers, filling missing values, etc., to ensure the accuracy and completeness of the data. The above historical mining data is divided according to the type of survey, and each survey method represents a dimension, thereby obtaining multi-dimensional historical data of low permeability oil and gas reservoirs. After the division, the multi-dimensional historical data needs to be stored for subsequent analysis and modeling.

[0026] S102. Extract features from the multi-dimensional historical data to obtain multi-dimensional feature data, input the multi-dimensional feature data into a predetermined low permeability oil layer analysis model, and determine the oil layer value score of the low permeability oil and gas reservoir through the low permeability oil layer analysis model.

[0027] In the identification and evaluation of low permeability oil and gas reservoirs, well logging faces two prominent difficulties: low signal-to-noise ratio and variable interpretation models. In terms of technical thinking, the fine interpretation of low permeability reservoir logging abandons the original single-well interpretation method of establishing interpretation models according to blocks and stratified sections. Instead, it establishes interpretation models based on the reservoir formation mechanism and control factors under low-amplitude closure conditions, using rock physical phase-logging phase correspondence analysis. This technology is based on high-precision CNC and imaging logging acquisition. Conventional logging methods rely on skeleton parameters to calculate porosity. In formations with complex lithology, it is very difficult to accurately determine rock skeleton parameters. Well logging usually uses sonic time difference to calculate porosity, but in dense formations, the cementation mode of mud and rock particles has a great influence on sonic logging, and the accuracy of porosity calculated by logging is difficult to guarantee. The basis for determining formation porosity by nuclear magnetic logging comes from the proportional relationship between the observed signal intensity and the content of hydrogen nuclei in the pore fluid. Since hydrogen nuclei in the rock skeleton have a very short relaxation time, their signals cannot be detected by instruments, so the interpreted porosity is independent of lithology.

[0028] Characteristic parameters are determined according to the historical survey type, where the characteristic parameters include but are not limited to porosity and irreducible water saturation. The permeability of low permeability oil and gas reservoirs is calculated according to the characteristic parameters. The calculation formula of permeability is:

[0029]

[0030] Where K is the permeability, is the porosity, S is the irreducible water saturation; the applicability of this formula is also relatively common. However, it is very difficult to obtain irreducible water saturation from conventional logging data. Nuclear magnetic resonance logging can use T spectrum analysis to obtain irreducible water saturation more accurately, thereby improving the effect of permeability evaluation. Multidimensional characteristic data are determined based on the porosity, irreducible water saturation and permeability, and these multidimensional characteristic data are formed into characteristic data in the form of a matrix.

[0031] In one embodiment, before establishing a low permeability oil layer analysis model, it is necessary to discretize the historical production data to generate corresponding data parameters in the study area. The attribute modeling selects the sequential Gaussian simulation method under phase control. When modeling, a variogram needs to be set to reflect the spatial correlation of reservoir parameters. The range of spatial correlation of a reservoir parameter is understood through the variogram. The parameters of the variogram include range, sill value, and nugget value. Use geostatistical software (such as GSLIB, GS+, etc.) to perform variogram analysis on the permeability data and fit the parameters of the variogram. The parameters of the permeability variogram are obtained, for example, the range is 100 meters, the sill value is 0.5 Darcy, and the nugget value is 0.05 Darcy. These parameters will be used for sequential Gaussian simulation. Permeability data often does not conform to the Gaussian distribution, and parameter conversion is required to apply the Gaussian simulation method.

[0032] Set the standard deviation to reflect the numerical variability of the rock physical parameters in each phase type. Set parameter transformation to make it conform to the Gaussian distribution through parameter transformation so that the Gaussian simulation method can be used for modeling. Use statistical software (such as SPSS, R, etc.) to check the distribution of permeability data. Select an appropriate transformation method based on the distribution of the data, such as logarithmic transformation, Box-Cox transformation, etc. In this example, logarithmic transformation is selected to transform the permeability data into a Gaussian distribution. Use the sequential Gaussian simulation method to combine the variogram and the transformed permeability data to establish a permeability model.

[0033] Set the correlation relationship to reflect the correlation degree of different types of rock physical parameters. Set the coarsening parameters to average the parameters in the well model on the scale of the simulation grid. In most cases, the well model is matched with the three-dimensional grid by the coarsening method. Select the appropriate coarsening method according to the physical meaning and geological characteristics of the parameters. The arithmetic mean method is used for the coarsening of porosity and irreducible water saturation, while the geometric mean method is used for permeability. On each unit of the simulation grid, the coarsened parameter value is calculated according to the well point data and the coarsening method. The coarsened parameter value is assigned to the corresponding unit of the three-dimensional grid to complete the matching of the well model with the three-dimensional grid. In this study, based on the corresponding data transformation of parameters such as phase type, sand body thickness, porosity, permeability and irreducible water saturation, the permeability, porosity, net-to-gross ratio model and irreducible water saturation model of the target reservoir are established by using the data analysis results and the sequential Gaussian simulation method to obtain the low permeability oil layer analysis model.

[0034] In one embodiment, the production equipment of low permeability oil and gas reservoirs is determined, and the production parameters of the production equipment are determined according to the characteristic parameters and permeability. These parameters may include injection pressure, oil production rate, water injection volume, oil recovery ratio, etc. The type of oil and gas reservoir that can be produced by the production equipment can be determined according to the production parameters, which involves the production of oil and gas reservoirs with different permeability values. The production parameters and multi-dimensional characteristic data are input into the low permeability oil layer analysis model. Through the low permeability oil layer analysis model, the weight corresponding to the multi-dimensional characteristic data is determined according to the production parameters; the cumulative oil production and water content data are analyzed using historical production data to determine the relationship between the cumulative oil production and water content in different production periods, and to clarify the wells with development contradictions in different development stages, such as production wells with high water content in the early stage of production. The water content includes low water content (0%-30%), medium water content (30%-60%), and high water content (60%-100%). The gray correlation method is used to divide the physical properties of the oil layer. Taking the test oil production as the main variable, the gray correlation method is used to obtain the weights of some parameters of the oil reservoir. First, the selected parameters are standardized to eliminate the physical meaning of each parameter and make each parameter on the same order of magnitude. First, the mean and standard deviation of each sequence are calculated respectively, and then the original data is subtracted from the mean and divided by the standard deviation. The new data sequence obtained is the standardized sequence. The dimension is that its mean is 0 and the variance is 1. After all parameters are standardized, the grey correlation between each indicator and the main indicator is further calculated. The oil layer value score is determined according to the weight and multi-dimensional feature data, and the parameter weight coefficient is multiplied by the standardized value of each parameter, and then the multiplied values ​​are added to obtain the oil layer value score.

[0035] S103. Determine a re-exploitation index of the low permeability oil and gas reservoir according to the oil layer value score, and determine a remaining type of the low permeability oil and gas reservoir according to the re-exploitation index, so as to determine a re-exploitation plan according to the remaining type.

[0036] In one embodiment, before determining the re-exploitation index of the low permeability oil and gas reservoir according to the oil layer value score, the environmental parameters of the low permeability oil and gas reservoir are determined. The environmental parameters include temperature, humidity, traffic conditions, etc. The exploitation value of the remaining oil and gas reservoir in a harsh environment is not high. The exploitation value threshold of the low permeability oil and gas reservoir is determined according to the environmental parameters and the exploitation parameters. The oil layer value score is compared with the exploitation value threshold; if the oil layer value score is greater than or equal to the exploitation value threshold, the re-exploitation index of the low permeability oil and gas reservoir is determined to continue exploitation; if the oil layer value score is less than the exploitation value threshold, the re-exploitation index of the low permeability oil and gas reservoir is determined to not continue exploitation.

[0037] In one embodiment, the re-exploitation index of the low permeability oil and gas reservoir is determined as follows: after continued exploitation, the remaining type of the low permeability oil and gas reservoir is determined according to environmental parameters and exploitation parameters, wherein the remaining types include but are not limited to uncontrolled well network type, imperfect injection and production type, retention type at the top of thick oil layer, river channel side zone type, interlayer interference type, and retention area type.

[0038] Micro-sand bodies usually refer to sandy sediments with small scale, complex morphology and wide distribution. Compared with large sand bodies, micro-sand bodies are usually smaller in scale and may be limited to a local area or sedimentary layer. Micro-sand bodies have various shapes and may present complex shapes such as irregular, branched, and lens-shaped. Although the scale of individual micro-sand bodies is small, they may be widely distributed in a certain area or sedimentary layer to form a dense sand body network. When the number of micro-sand bodies in a certain area or sedimentary layer is large and the distribution is dense, it can be considered that the micro-sand bodies in the area are highly developed. For fluvial reservoirs, micro-sand bodies with a thickness of less than 1 to 2 meters and a width of less than 200 to 300 meters are relatively developed. Even many periods of main river channels, abandoned river channels, ditch fillings, breach fans and other sand bodies belong to this type of sand body. Its oil abundance is high, but it is difficult to control its distribution for most well networks, so it is the focus of tapping the potential of remaining oil. Imperfect injection and production type residual oil is an important way for the formation of residual oil in the severe planar heterogeneity of thick oil layers. In the original well network, only oil wells or only water wells are drilled into river sand bodies; oil and water wells are connected through thin sand layers between rivers; or there are large areas of low permeability layers between oil and water wells, which may cause imperfect injection and production and form residual oil. In a broad sense, imperfect injection and production are also caused by oil layer pollution, casing damage, and second-line effect, forming the potential for residual oil. Retained residual oil at the top of thick oil layers, due to the presence of interlayers and permeability differences in the thick oil layers, the injected water advances along the high permeability zone at the bottom of the oil layer, while the injected water at the top of the thick oil layer is not affected or is affected very weakly, thus forming residual oil. Residual oil in the splicing zone of the river channel or the irregular edge of the river channel, in the large-area distributed sand body composed of multiple river channel sand bodies, under the conditions of large row spacing and sparse well network injection and production, because the injected water preferentially advances along the main zone of each river channel, a strip of residual oil is left in the splicing zone of different river channel sands. At the same time, the edges of the sand bodies in a single river channel are tortuous and changeable in some local areas, and the water drive effect is poor, resulting in residual oil. In the case of multi-layer joint injection and production, due to the heterogeneity of the layers, the low permeability layer is difficult to mobilize under the same production pressure difference, thus forming a residual oil enrichment area. The residual oil in the retention area forms a pressure balance area between the injection wells, between the group-shaped oil production wells, and between the edge water and the injection wells, forming a retained residual oil.

[0039] In one embodiment, the distribution characteristics of the remaining oil layer of the low permeability oil and gas reservoir are determined according to the remaining type, and the distribution model of the remaining oil layer of the low permeability oil and gas reservoir is determined according to the distribution characteristics of the remaining oil layer. By analyzing the heterogeneity characteristics of the sand body in the plane and vertical direction of the river phase reservoir, the vertical and plane remaining oil distribution patterns of the reservoir in the study area are studied. For example, the remaining oil in the sand body of the high river phase reservoir is distributed in different parts of the sand body in the form of dispersed phase, sheet, and aggregate block. Among them, for each thick river channel sand oil layer, the water-washed part in the lower coarse grains is mainly dispersed phase residual oil or mud wedge retention residual oil; the middle part is the transition section, which is partially water-washed; the upper siltstone and mudstone, which are partially water-washed and unwashed, are mainly layered low permeability remaining oil. Interlayer interference type residual oil is formed between different sand bodies with large permeability differences due to interlayer interference. The side edges of the main body of the channel sand are mainly thin layers of nearly unflooded residual oil layers and up-dip pinch-out residual oil caused by breach scallops or overflow banks, while in any part of the composite sand body, there may be missed micro-sand bodies, micro-structural types, and extended fault-edge residual oil. The current distribution of the remaining oil in the reservoir is obtained through numerical simulation of the reservoir. For example, due to the small injection-production ratio and the long distance between the bottom water and the oil-water relationship in the oil layer, a large amount of residual oil remains. In some well areas, flooding occurs due to the invasion of edge and bottom water. According to the distribution model of the remaining oil layer, the corresponding re-exploitation plan is set. On the basis of correctly understanding the distribution change law and control factors of the remaining oil in the reservoir, the potential for improving the reserve utilization degree and water drive efficiency is further analyzed, and then the re-exploitation plan is set according to the analysis results.

[0040] like Figure 2 As shown, the embodiment of the present application also provides a low permeability oil and gas reservoir survey and description device, including:

[0041] at least one processor; and,

[0042] a memory communicatively connected to at least one processor; wherein,

[0043] The memory stores instructions executable by at least one processor, the instructions being executed by the at least one processor to enable a low permeability oil and gas reservoir survey and description apparatus to be performed.

[0044] The historical production data of the low permeability oil and gas reservoir is obtained, and the historical production data is divided according to a preset data dimension to obtain multi-dimensional historical data of the low permeability oil and gas reservoir.

[0045] Feature extraction is performed on the multi-dimensional historical data to obtain multi-dimensional feature data; the multi-dimensional feature data is input into a predetermined low permeability oil layer analysis model, and the oil layer value score of the low permeability oil and gas reservoir is determined by the low permeability oil layer analysis model.

[0046] The re-production index of the low permeability oil and gas reservoir is determined according to the oil layer value score, and the remaining type of the low permeability oil and gas reservoir is determined according to the re-production index, so as to determine a re-production plan according to the remaining type.

[0047] The embodiment of the present application further provides a non-volatile computer storage medium storing computer executable instructions, wherein the computer executable instructions are configured as follows:

[0048] Acquire historical production data of a low permeability oil and gas reservoir, and divide the historical production data according to a preset data dimension to obtain multi-dimensional historical data of the low permeability oil and gas reservoir;

[0049] Extracting features from the multi-dimensional historical data to obtain multi-dimensional feature data, inputting the multi-dimensional feature data into a predetermined low permeability oil layer analysis model, and determining the oil layer value score of the low permeability oil and gas reservoir through the low permeability oil layer analysis model;

[0050] The re-production index of the low permeability oil and gas reservoir is determined according to the oil layer value score, and the remaining type of the low permeability oil and gas reservoir is determined according to the re-production index, so as to determine a re-production plan according to the remaining type.

[0051] In the 1990s, it was very clear whether the improvement of a technology was hardware improvement (for example, improvement of the circuit structure of diodes, transistors, switches, etc.) or software improvement (improvement of the method flow). However, with the development of technology, many improvements of the method flow today can be regarded as direct improvements of the hardware circuit structure. Designers almost always obtain the corresponding hardware circuit structure by programming the improved method flow into the hardware circuit. Therefore, it cannot be said that the improvement of a method flow cannot be implemented with hardware entity modules. For example, a programmable logic device (PLD) (such as a field programmable gate array (FPGA)) is such an integrated circuit whose logical function is determined by the user's programming of the device. Designers can "integrate" a digital system on a PLD by programming it themselves, without having to ask chip manufacturers to design and make dedicated integrated circuit chips. Moreover, nowadays, instead of making integrated circuit chips manually, this kind of programming is mostly implemented by "logic compiler" software, which is similar to the software compiler used when developing and writing programs, and the original code before compilation must also be written in a specific programming language, which is called hardware description language (HDL). And there is not only one kind of HDL, but many kinds, such as ABEL (Advanced Boolean Expression Language), AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description Language), etc. The most commonly used ones are VHDL (Very-High-Speed ​​Integrated Circuit Hardware Description Language) and Verilog. Those skilled in the art should also know that it is only necessary to program the method flow slightly in the above-mentioned hardware description languages ​​and program it into the integrated circuit, and then it is easy to obtain the hardware circuit that implements the logic method flow.

[0052] The controller may be implemented in any suitable manner, for example, the controller may take the form of a microprocessor or processor and a computer-readable medium storing a computer-readable program code (e.g., software or firmware) executable by the (micro)processor, a logic gate, a switch, an ASIC (Application Specific Integrated Circuit), a programmable logic controller, and an embedded microcontroller. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320. The memory controller may also be implemented as part of the control logic of the memory. It is also known to those skilled in the art that, in addition to implementing the controller in a purely computer-readable program code manner, the controller may be implemented in the form of a logic gate, a switch, an ASIC, a programmable logic controller, and an embedded microcontroller by logically programming the method steps. Therefore, such a controller may be considered as a hardware component, and the devices included therein for implementing various functions may also be considered as structures within the hardware component. Even more, the devices for implementing various functions may be considered as both software modules for implementing the method and structures within the hardware component.

[0053] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer may be a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0054] For the convenience of description, the above device is described by dividing it into various units according to its function. Of course, when implementing this specification, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0055] Each embodiment in this application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device and medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0056] The device and medium provided in the embodiments of the present application correspond one-to-one with the method, so the device and medium also have similar beneficial technical effects as the corresponding method. Since the beneficial technical effects of the method have been described in detail above, the beneficial technical effects of the device and medium will not be repeated here.

[0057] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0058] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0059] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0060] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0061] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0062] Memory may include non-permanent storage in a computer-readable medium, in the form of random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

[0063] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0064] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0065] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A method for surveying and describing low permeability oil and gas reservoirs, characterized in that: include: Acquire historical production data of a low permeability oil and gas reservoir, and divide the historical production data according to a preset data dimension to obtain multi-dimensional historical data of the low permeability oil and gas reservoir; Extracting features from the multi-dimensional historical data to obtain multi-dimensional feature data, inputting the multi-dimensional feature data into a predetermined low permeability oil layer analysis model, and determining the oil layer value score of the low permeability oil and gas reservoir through the low permeability oil layer analysis model; Determine the re-exploitation index of the low permeability oil and gas reservoir according to the oil layer value score, determine the remaining type of the low permeability oil and gas reservoir according to the re-exploitation index, and determine the re-exploitation plan according to the remaining type; Determine the historical survey type of the low permeability oil and gas reservoir, and determine the data dimension according to the historical survey type, wherein the historical survey type includes but is not limited to physical survey, drilling survey, and logging survey; Extracting features from the multi-dimensional historical data specifically includes: Determine characteristic parameters according to the historical survey type, wherein the characteristic parameters include but are not limited to porosity and irreducible water saturation; The permeability of the low permeability oil and gas reservoir is calculated according to the characteristic parameters, and the calculation formula of the permeability is: Wherein, K is the permeability, is the porosity, S is the irreducible water saturation; Determining the multi-dimensional characteristic data according to the porosity, irreducible water saturation and permeability; Determining the oil layer value score of the low permeability oil and gas reservoir by using the low permeability oil layer analysis model specifically includes: Determine the production equipment of the low permeability oil and gas reservoir, determine the production parameters of the production equipment according to the characteristic parameters and the permeability, and input the production parameters and the multi-dimensional characteristic data into the low permeability oil layer analysis model; Determine the weight corresponding to the multi-dimensional feature data according to the production parameters by using the low permeability oil layer analysis model; The oil layer value score is determined according to the weight and the multi-dimensional feature data.

2. The method according to claim 1, characterized in that Before determining the re-production index of the low permeability oil and gas reservoir according to the oil layer value score, the method further includes: Determine the environmental parameters of the low permeability oil and gas reservoir, determine the exploitation value threshold of the low permeability oil and gas reservoir according to the environmental parameters and the exploitation parameters, and compare the oil layer value score with the exploitation value threshold; If the oil layer value score is greater than or equal to the exploitation value threshold, determining the re-exploitation index of the low permeability oil and gas reservoir to continue exploitation; If the oil layer value score is less than the exploitation value threshold, the re-exploitation index of the low permeability oil and gas reservoir is determined to be not to continue exploitation.

3. The method according to claim 2, characterized in that After determining that the re-production index of the low permeability oil and gas reservoir is to continue production, the method further includes: The remaining type of the low permeability oil and gas reservoir is determined according to the environmental parameters and the production parameters, wherein the remaining type includes but is not limited to uncontrolled well network type, imperfect injection and production type, retention type at the top of thick oil layer, river channel side zone type, interlayer interference type, and retention area type.

4. The method according to claim 1, characterized in that: The method further comprises: Determining the remaining oil layer distribution characteristics of the low permeability oil and gas reservoir according to the remaining type, and determining the remaining oil layer distribution model of the low permeability oil and gas reservoir according to the remaining oil layer distribution characteristics; A corresponding re-exploitation plan is set according to the remaining oil layer distribution model.

5. The method according to claim 1, characterized in that: Before inputting the multi-dimensional characteristic data into a predetermined low permeability oil layer analysis model, the method further comprises: The exploitation cases of the low permeability oil and gas reservoirs are determined according to the historical exploitation data, and the exploitation cases are input into a neural network model for model training to obtain the low permeability oil layer analysis model.

6. A survey and description device for low permeability oil and gas reservoirs, characterized in that: include: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the low permeability oil and gas reservoir survey and description device to perform: Acquire historical production data of a low permeability oil and gas reservoir, and divide the historical production data according to a preset data dimension to obtain multi-dimensional historical data of the low permeability oil and gas reservoir; Extracting features from the multi-dimensional historical data to obtain multi-dimensional feature data, inputting the multi-dimensional feature data into a predetermined low permeability oil layer analysis model, and determining the oil layer value score of the low permeability oil and gas reservoir through the low permeability oil layer analysis model; Determine a re-exploitation index of the low permeability oil and gas reservoir according to the oil layer value score, and determine a residual type of the low permeability oil and gas reservoir according to the re-exploitation index, so as to determine a re-exploitation plan according to the residual type; Determine the historical survey type of the low permeability oil and gas reservoir, and determine the data dimension according to the historical survey type, wherein the historical survey type includes but is not limited to physical survey, drilling survey, and logging survey; Extracting features from the multi-dimensional historical data specifically includes: Determine characteristic parameters according to the historical survey type, wherein the characteristic parameters include but are not limited to porosity and irreducible water saturation; The permeability of the low permeability oil and gas reservoir is calculated according to the characteristic parameters, and the calculation formula of the permeability is: Wherein, K is the permeability, is the porosity, S is the irreducible water saturation; Determining the multi-dimensional characteristic data according to the porosity, irreducible water saturation and permeability; Determining the oil layer value score of the low permeability oil and gas reservoir by using the low permeability oil layer analysis model specifically includes: Determine the production equipment of the low permeability oil and gas reservoir, determine the production parameters of the production equipment according to the characteristic parameters and the permeability, and input the production parameters and the multi-dimensional characteristic data into the low permeability oil layer analysis model; Determine the weight corresponding to the multi-dimensional feature data according to the production parameters by using the low permeability oil layer analysis model; The oil layer value score is determined according to the weight and the multi-dimensional feature data.

7. A non-volatile computer storage medium storing computer executable instructions, characterized in that: The computer executable instructions are configured to: Acquire historical production data of a low permeability oil and gas reservoir, and divide the historical production data according to a preset data dimension to obtain multi-dimensional historical data of the low permeability oil and gas reservoir; Extracting features from the multi-dimensional historical data to obtain multi-dimensional feature data, inputting the multi-dimensional feature data into a predetermined low permeability oil layer analysis model, and determining the oil layer value score of the low permeability oil and gas reservoir through the low permeability oil layer analysis model; Determine a re-exploitation index of the low permeability oil and gas reservoir according to the oil layer value score, and determine a residual type of the low permeability oil and gas reservoir according to the re-exploitation index, so as to determine a re-exploitation plan according to the residual type; Determine the historical survey type of the low permeability oil and gas reservoir, and determine the data dimension according to the historical survey type, wherein the historical survey type includes but is not limited to physical survey, drilling survey, and logging survey; Extracting features from the multi-dimensional historical data specifically includes: Determine characteristic parameters according to the historical survey type, wherein the characteristic parameters include but are not limited to porosity and irreducible water saturation; The permeability of the low permeability oil and gas reservoir is calculated according to the characteristic parameters, and the calculation formula of the permeability is: Wherein, K is the permeability, is the porosity, S is the irreducible water saturation; Determining the multi-dimensional characteristic data according to the porosity, irreducible water saturation and permeability; Determining the oil layer value score of the low permeability oil and gas reservoir by using the low permeability oil layer analysis model specifically includes: Determine the production equipment of the low permeability oil and gas reservoir, determine the production parameters of the production equipment according to the characteristic parameters and the permeability, and input the production parameters and the multi-dimensional characteristic data into the low permeability oil layer analysis model; Determine the weight corresponding to the multi-dimensional feature data according to the production parameters by using the low permeability oil layer analysis model; The oil layer value score is determined according to the weight and the multi-dimensional feature data.

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