Oil and gas reservoir identification method based on isochronous stratigraphic framework stratigraphic fine comparison

Abstract

The invention discloses a hydrocarbon reservoir identification method based on isochronous stratigraphic framework stratigraphic fine comparison, and relates to the technical field of petroleum logging, and the method comprises the steps: determining a first sequence interface set based on logging curve characteristics, and determining a second sequence interface set based on well-side seismic information and logging information; determining a target sequence interface set in the first sequence interface set and the second sequence interface set, and determining an isochronous stratigraphic framework by using the target sequence interface set; on the basis of the core data and a preset Archie formula, rock-electricity parameters and formation water resistivity are determined, and the porosity is calculated on the basis of the determined target porosity evaluation model; determining oil saturation of each sequence in the isochronous stratigraphic framework on the basis of the rock electricity parameters, the formation water resistivity, the porosity and a preset Archie formula, and comparing reservoir units on the basis of the logging curve, so as to identify oil and gas reservoirs in each sequence by using the obtained comparison result, the porosity and the oil saturation. The reliability of hydrocarbon reservoir identification is improved.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum well logging, and in particular to a method for identifying oil and gas layers based on isochronous stratigraphic grid and stratigraphic fine comparison. Background Art

[0002] In the process of oil and gas exploration and development, reservoir correlation is the key prerequisite for accurately identifying oil and gas layers.

[0003] At present, logging technicians mostly use lithologic stratigraphic correlation method in reservoir evaluation. That is, based on the similar geophysical logging response characteristics of specific lithologic strata in the same formation, according to the principle of "mudstone to mudstone, sandstone to sandstone", the oil and gas layers are identified by changes in logging curves such as resistivity and porosity between wells, and by referring to the oil and gas layer identification standards established by oil test results. However, this method has many defects. First, the morphology of logging curves in different formations may be similar, which may easily lead to formation comparison errors. Secondly, logging data can only reflect part of the formation information. For complex formations, the similarity of logging curves is poor, making it difficult to achieve accurate comparison. Furthermore, when a sudden change occurs in the formation, the logging curve will be abnormal, which will seriously affect the accuracy of formation comparison. As a result, the same small layer between wells under lithologic stratigraphic comparison is not in the same sedimentary environment, and there are differences in their formation water resistivity and rock electrical parameters. The oil and gas saturation calculated based on this lacks comparability between wells, and the measured resistivity, porosity and other logging curves have no lateral comparison significance, which makes it difficult to meet the needs of efficient oil and gas exploration and development.

[0004] Therefore, how to improve the accuracy and efficiency of oil and gas layer identification is an urgent problem to be solved. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method for identifying oil and gas layers based on isochronous stratigraphic grid fine stratum comparison, which can improve the accuracy and efficiency of oil and gas layer identification. The specific scheme is as follows:

[0006] In a first aspect, the present application provides a method for identifying oil and gas layers based on isochronous stratigraphic framework stratigraphic fine correlation, comprising:

[0007] In the target oil and gas exploration area, a first sequence interface set is determined based on the characteristics of the well logging curve, and a second sequence interface set is determined based on the seismic information near the well and the well logging information;

[0008] Determining a target sequence interface set from the first sequence interface set and the second sequence interface set based on a preset interface determination rule, and determining an isochronous stratigraphic framework using the target sequence interface set to calibrate sequences in the isochronous stratigraphic framework;

[0009] Under the isochronous stratigraphic framework, the rock electrical parameters and formation water resistivity of each of the sequences are determined based on core data and a preset Archie formula, and a target porosity evaluation model of each of the sequences is determined based on three-porosity logging curve information and the core data, so as to determine the porosity of the sequence using the target porosity evaluation model;

[0010] The oil saturation of each of the sequences is determined based on the rock electrical parameters, the formation water resistivity, the porosity and the preset Archie formula, and reservoir unit comparison is performed based on the logging curve to identify the oil and gas layers in each of the sequences using the comparison results, the porosity and the oil saturation.

[0011] Optionally, determining the first sequence interface set based on the well logging curve characteristics includes:

[0012] A well including drilling coring information and logging information is used as a key well, and the logging information is modified using core data to construct a standard profile of the key well based on the modified logging information;

[0013] In the standard section, a first sequence interface set is determined based on the logging curve characteristics in the logging information.

[0014] Optionally, determining the second sequence interface set based on wellside seismic information and well logging information includes:

[0015] Determine a synthetic seismic record based on the acoustic wave curve and the density curve in the well logging information, and modify the synthetic seismic record according to the wellside seismic information to obtain the synthetic seismic record that meets the preset similarity condition;

[0016] A seismic profile of the key well is constructed based on the modified well logging information, and a second sequence interface set is determined in the seismic profile using the seismic synthetic records that meet the preset similarity conditions.

[0017] Optionally, the determining of the rock electrical parameters and formation water resistivity of each sequence based on the core data and the preset Archie formula includes:

[0018] Obtaining formation factors, porosity data, resistivity increase coefficient, water saturation and formation water information from the core data;

[0019] Determine the rock electrical parameters of each of the sequences based on the preset Archie formula, the formation factors, the porosity data, the resistivity increase coefficient and the water saturation;

[0020] Converting the ion mineralization into an equivalent NaCl mineralization based on an equivalent coefficient of the ion mineralization in the formation water information, and determining the formation water resistivity under experimental test conditions using the equivalent NaCl mineralization;

[0021] The formation water resistivity under formation conditions is determined based on a preset conversion formula and the formation water resistivity under the experimental test conditions.

[0022] Optionally, determining the target porosity evaluation model for each sequence based on the three-porosity logging curve information and the core data includes:

[0023] Modifying the depth information in the core data according to the depth information in the well logging information to obtain target depth information in which the depth information of the core data is consistent with the depth information in the well logging information;

[0024] Acquire three-porosity logging curve information of corresponding depth based on the target depth information, and respectively determine the relationship information of the porosity data and the acoustic wave, density and neutron in the three-porosity logging curve information;

[0025] Converting the relationship information into a relationship curve, and performing single-item fitting or multi-item fitting using the relationship curve and the porosity data to obtain each porosity evaluation model;

[0026] Among the porosity evaluation models, a porosity evaluation model that meets a preset correlation condition is determined as a target porosity evaluation model.

[0027] Optionally, the reservoir unit comparison based on the well logging curve includes:

[0028] The logging curves satisfying the preset sensitivity conditions in the logging information are determined as comparison curves, and reservoir units of the tested wells and the wells to be tested are compared based on the comparison curves to obtain comparison results.

[0029] Optionally, the identifying the oil and gas layers in each of the sequences by using the obtained comparison results, the porosity and the oil saturation includes:

[0030] Obtaining the reservoir unit lithology and curve change information in the comparison results;

[0031] The reservoir type of each of the sequences is determined based on the reservoir unit lithology, the curve change information, the porosity and the oil saturation, so as to determine the oil and gas layers in each of the sequences using the reservoir type.

[0032] In a second aspect, the present application provides a device for identifying oil and gas layers based on isochronous stratigraphic grid fine stratum comparison, comprising:

[0033] An interface determination module is used to determine a first sequence interface set based on well logging curve characteristics and a second sequence interface set based on wellside seismic information and well logging information in a target oil and gas exploration area;

[0034] a framework determination module, configured to determine a target sequence interface set in the first sequence interface set and the second sequence interface set based on a preset interface determination rule, and determine an isochronous stratigraphic framework using the target sequence interface set to calibrate sequences in the isochronous stratigraphic framework;

[0035] A porosity determination module, for determining the rock electrical parameters and formation water resistivity of each of the sequences under the isochronous stratigraphic framework based on core data and a preset Archie formula, and determining a target porosity evaluation model for each of the sequences based on three-porosity logging curve information and the core data, so as to determine the porosity of the sequence using the target porosity evaluation model;

[0036] The oil and gas layer identification module is used to determine the oil saturation of each of the sequences based on the rock electrical parameters, the formation water resistivity, the porosity and the preset Archie formula, and to compare reservoir units based on the logging curves, so as to identify the oil and gas layers in each of the sequences using the comparison results, the porosity and the oil saturation.

[0037] In a third aspect, the present application provides an electronic device, including:

[0038] Memory, used to store computer programs;

[0039] The processor is used to execute the computer program to implement the aforementioned method for identifying oil and gas layers based on isochronous stratigraphic framework and fine stratigraphic comparison.

[0040] In a fourth aspect, the present application provides a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the aforementioned method for identifying oil and gas layers based on fine comparison of isochronous stratigraphic frameworks is implemented.

[0041] In the present application, in the target oil and gas exploration area, a first sequence interface set is determined based on the characteristics of the well logging curve, and a second sequence interface set is determined based on the wellside seismic information and the well logging information; a target sequence interface set is determined in the first sequence interface set and the second sequence interface set based on a preset interface determination rule, and an isochronous stratigraphic framework is determined using the target sequence interface set to calibrate the sequence in the isochronous stratigraphic framework; under the isochronous stratigraphic framework, the rock electrical parameters of each sequence are determined based on the core data and the preset Archie formula. number and formation water resistivity, and determine the target porosity evaluation model of each of the sequences based on the three-porosity logging curve information and the core data, so as to determine the porosity of the sequence using the target porosity evaluation model; determine the oil saturation of each of the sequences based on the rock electrical parameters, the formation water resistivity, the porosity and the preset Archie formula, and compare reservoir units based on the logging curves, so as to identify the oil and gas layers in each of the sequences using the comparison results, the porosity and the oil saturation. As can be seen from the above, the present application first obtains the first sequence interface set based on the logging curve characteristics, and obtains the second sequence interface set based on the wellside seismic information and logging information. Determine the target sequence interface set from the two according to the preset rules, and construct an isochronous stratigraphic framework and calibrate the sequence accordingly. Under this framework, the rock electrical parameters and formation water resistivity of the sequence are determined by core data and the preset Archie formula, and the target porosity evaluation model is determined based on the three-porosity logging curve and core data to calculate the porosity. The oil saturation is then calculated based on the rock electrical parameters, formation water resistivity, porosity and the preset Archie formula, and the reservoir unit comparison is carried out based on the logging curve. The oil and gas layers in each sequence are identified by the comparison results, porosity and oil saturation. In this way, this application can improve the accuracy and efficiency of oil and gas layer identification, thereby enhancing the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0043] Figure 1 A flow chart of a method for identifying oil and gas layers based on isochronous stratigraphic grid and fine stratigraphic comparison disclosed in the present application;

[0044] Figure 2 A schematic diagram of an isochronous stratigraphic framework in a target oil and gas exploration area disclosed in the present application;

[0045] Figure 3 A schematic diagram of the relationship between formation factors and porosity disclosed in this application;

[0046] Figure 4 A schematic diagram of the relationship between a resistance increase coefficient and water saturation disclosed in the present application;

[0047] Figure 5 A schematic diagram of the relationship between density, acoustic wave, neutron and porosity data in SH5 disclosed in this application;

[0048] Figure 6 A schematic diagram of the comprehensive results of the X1 well disclosed in this application;

[0049] Figure 7 A schematic diagram of the comprehensive results of the X2 well disclosed in this application;

[0050] Figure 8 A schematic diagram of the comprehensive results of Well X3 (left) and Well X4 (right) disclosed in this application;

[0051] Fig. 9 A schematic diagram of the comprehensive results of Well X5 (left) and Well X6 (right) disclosed in this application;

[0052] Fig.10 This is a schematic diagram of the structure of an oil and gas layer identification device based on isochronous stratigraphic grid fine stratum comparison disclosed in the present application;

[0053] Fig.11 This is a structural diagram of an electronic device disclosed in this application. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0055] For the current reservoir evaluation methods, the logging curves of different strata may be similar in shape, which can easily lead to errors in stratigraphic comparison. Secondly, logging data can only reflect part of the stratigraphic information. For complex strata, the logging curves have poor similarity and are difficult to achieve accurate comparison. Furthermore, when a sudden change occurs in the stratum, the logging curve will be abnormal, which seriously affects the accuracy of stratigraphic comparison. As a result, the same sublayer between wells under lithologic stratigraphic comparison is not in the same sedimentary environment, and there are differences in their formation water resistivity and rock electrical parameters. The oil and gas saturation calculated based on this lacks comparability between wells, and the measured resistivity, porosity and other logging curves have no lateral comparison significance, which is difficult to meet the needs of efficient oil and gas exploration and development. To this end, the present application provides a method for identifying oil and gas layers based on fine stratigraphic comparison of isochronous stratigraphic frameworks, which can improve the accuracy and efficiency of oil and gas layer identification.

[0056] See also Figure 1 As shown, the embodiment of the present application discloses a method for identifying oil and gas layers based on isochronous stratigraphic framework stratigraphic fine comparison, comprising:

[0057] Step S11: In the target oil and gas exploration area, a first sequence interface set is determined based on the characteristics of the well logging curves, and a second sequence interface set is determined based on the wellside seismic information and the well logging information.

[0058] In this embodiment, a well containing drilling coring information and logging information is taken as a key well, and the logging information is modified using core data to construct a standard profile of the key well based on the modified logging information. It should be noted that for key wells, the information contained therein is relatively comprehensive and representative, and can provide a solid data basis for subsequent analysis. The operation of modifying the logging information using core data is intended to further improve the reliability of the logging information. Core data is the most intuitive reflection of underground rock formations. It is used to calibrate logging information so that the logging information can better fit the actual formation conditions. On this basis, the standard profile of the key well is constructed based on the modified logging information. This standard profile is like a precise reference system, providing a framework for the subsequent determination of the sequence interface set.

[0059] After the standard section is determined, the first sequence interface set is determined in the standard section based on the logging curve characteristics in the logging information. Specifically, the logging curve characteristics include but are not limited to resistivity curve characteristics, natural gamma curves, etc. Different formations often have obvious differences in logging curve characteristics such as resistivity and natural gamma. For example, sandstone formations may show the characteristics of low natural gamma values ​​and high resistivity values, while mudstone formations are the opposite, showing high natural gamma values ​​and low resistivity values. By analyzing many details such as the numerical changes and morphological characteristics of these logging curves, the interfaces that divide different sequences can be identified, and then the first sequence interface set can be determined. For example, the first sequence interface set can be named sequence interface a.

[0060] In this embodiment, a synthetic seismic record is determined based on the acoustic wave curve and density curve in the well logging information, and the synthetic seismic record is modified according to the wellside seismic information to obtain the synthetic seismic record that meets the preset similarity condition. It should be noted that the acoustic wave curve and the density curve each reflect the physical properties of different aspects of the formation, and they can be combined by specific technical means to generate a synthetic seismic record, which simulates the response of the formation under the action of an earthquake to some extent. However, the initially generated synthetic seismic record may not fully meet the actual requirements, so it is necessary to modify it according to the wellside seismic information until a synthetic seismic record that meets the preset similarity condition is obtained. Among them, the preset similarity condition is to make the synthetic seismic record have the maximum similarity with the wellside seismic information.

[0061] Further, in this embodiment, a seismic profile of the key well is constructed based on the modified well logging information, and a second sequence interface set is determined in the seismic profile using the seismic synthetic records that meet the preset similarity condition. For example, the second sequence interface set can be named sequence interface b.

[0062] Step S12: determining a target sequence interface set in the first sequence interface set and the second sequence interface set based on a preset interface determination rule, and determining an isochronous stratigraphic framework using the target sequence interface set to calibrate sequences in the isochronous stratigraphic framework.

[0063] It should be noted that the process of determining the target sequence interface set in the first sequence interface set and the second sequence interface set needs to be carried out under the constraint of the seismic profile, that is, the target sequence interface set needs to be determined in the first sequence interface set and the second sequence interface set based on the preset interface determination rule. It can be understood that the seismic profile can clearly show the distribution form, thickness change and continuity of the strata in the underground, and this information provides an intuitive and important reference for the comparison of sequence interfaces.

[0064] After the target sequence interface set is determined, the isochronous stratigraphic framework can be determined based on the target sequence interface set. The constructed isochronous stratigraphic framework can be as follows: Figure 2 As shown in the figure, SH1, SH2, SH3, SH4, SH5, SH6, SH7, SH8, SH9, SH10 and SH11 are 11 IV sequences calibrated in the isochronous stratigraphic framework, and the dividing line between sequences is the sequence interface. After subsequent operations, it can be determined that the oil and gas layers are mainly located in SH3, SH5 and SH8.

[0065] Step S13, under the isochronous stratigraphic framework, determine the rock electrical parameters and formation water resistivity of each of the sequences based on the core data and the preset Archie formula, and determine the target porosity evaluation model of each of the sequences based on the three-porosity logging curve information and the core data, so as to determine the porosity of the sequence using the target porosity evaluation model.

[0066] In this embodiment, the determination of rock electrical parameters and formation water resistivity and subsequent processes are all carried out under an isochronous stratigraphic framework, that is, under a relatively accurate and unified geological background. Specifically, firstly, the stratigraphic factors, porosity data, resistivity increase coefficient, water saturation and formation water information in the core data are obtained.

[0067] Furthermore, in this embodiment, the rock electrical parameters of each sequence are determined based on the preset Archie formula, the formation factors, the porosity data, the resistivity increase coefficient and the water saturation. The rock electrical parameters may include a (i.e., a lithology coefficient related to lithology), b (i.e., a constant related to lithology), m (i.e., ) and n (also known as the saturation index). In addition, the Archie formula for a pure water layer is as follows:

[0068] ;

[0069] Where F is the formation factor, is the porosity data. For example, see Figure 3 As shown in the figure, with formation factor F as the ordinate and porosity as the On the double logarithmic coordinates with the horizontal axis, the slope of the straight line is m. =100% is a. Therefore, we can first calculate F, The natural logarithm of the rock electrical parameters is obtained by making a cross plot of the two and obtaining a=1.6223 and m=1.6729.

[0070] In this embodiment, the Archie formula for a pure oil layer is as follows:

[0071] ;

[0072] Where I is the resistance increase coefficient, S w is the water saturation. For example, see Figure 4 As shown in the figure, the resistance increase coefficient I is taken as the ordinate and the water saturation S is taken as the ordinate. w On the double logarithmic coordinates with the horizontal axis, the slope of the straight line is n, S w =100% is b. Therefore, we can first calculate I and S w The natural logarithm of the rock electrical parameters is obtained by making a cross plot of the two, and b=1.0605 and n=1.508.

[0073] At the same time, in this embodiment, the ion mineralization is converted into an equivalent NaCl mineralization based on the equivalent coefficient of the ion mineralization in the formation water information, and the formation water resistivity under the experimental test conditions is determined using the equivalent NaCl mineralization. When the temperature in the experimental test is 24°C, the calculation formula for the formation water resistivity can be as follows:

[0074] ;

[0075] In the formula, R wl is the formation water resistivity, P w is the equivalent NaCl mineralization.

[0076] After calculating the formation water resistivity under the experimental test conditions, the formation water resistivity under the formation conditions is determined based on a preset conversion formula and the formation water resistivity under the experimental test conditions. The preset conversion formula is as follows:

[0077] ;

[0078] In the formula, R w is the formation water resistivity under formation conditions, T l 、T f are the laboratory temperature (i.e. the temperature under experimental test conditions, 24°C) and the formation temperature, respectively, and T f The calculation formula is as follows:

[0079] ;

[0080] Where, T s is the surface temperature (in °C), g D is the geothermal gradient (in °C / 100 m), and H is the formation depth (in meters).

[0081] In this embodiment, the rock electrical parameters and formation water resistivity of SH3, SH5 and SH8 may be as shown in Table 1.

[0082] Table 1

[0083]

[0084] Furthermore, in this embodiment, a porosity evaluation model for each sequence in the target oil and gas exploration area is determined. Specifically, the depth information in the core data is modified according to the depth information in the well logging information to obtain target depth information in which the depth information of the core data is consistent with the depth information in the well logging information;

[0085] After obtaining the target depth information, the three-porosity logging curve information of the corresponding depth is obtained based on the target depth information, and the relationship information between the porosity data and the acoustic wave, density and neutron in the three-porosity logging curve information is determined respectively. Figure 5 As shown in FIG. 1 , it is a relationship image between the porosity data corresponding to SH5 and the acoustic wave, density and neutron in the three-porosity logging curve information. Figure 5 It can be seen that the correlation coefficient between acoustic wave and porosity data in SH5 is the best, while the density and porosity data, neutron and porosity data, are affected by lithology and fluid in the pores, have large numerical changes, and have poor correlation with porosity data.

[0086] In this embodiment, the relationship information is converted into a relationship curve, and the relationship curve and the porosity data are used to perform single-item fitting or multi-item fitting to obtain each porosity evaluation model; in each porosity evaluation model, the porosity evaluation model that meets the preset correlation condition is determined as the target porosity evaluation model. In addition, as shown in Table 2, for the above-selected sequence with oil and gas layers, the neutron, density, and acoustic wave ternary regression model is finally selected as the basis for calculating the SH3 formation porosity, the acoustic wave univariate regression model is used as the basis for calculating the SH5 formation porosity, and the neutron and acoustic wave binary regression model is used as the basis for calculating the SH8 formation porosity.

[0087] Table 2

[0088]

[0089] Step S14, determining the oil saturation of each of the sequences based on the rock electrical parameters, the formation water resistivity, the porosity and the preset Archie formula, and performing reservoir unit comparison based on the logging curve, so as to identify the oil and gas layers in each of the sequences using the comparison results, the porosity and the oil saturation.

[0090] In this embodiment, the water saturation of each sequence is first determined according to the rock electrical parameters, the formation water resistivity and the porosity. The formula for calculating the water saturation is as follows:

[0091] ;

[0092] In the formula, S w is water saturation (in %), R t is the reservoir resistivity (in Ω·m).

[0093] The oil saturation of each sequence is determined based on the calculated water saturation and oil saturation calculation formulas. The calculation formula for oil saturation is as follows:

[0094] S O =1-S W ;

[0095] In the formula, S O is the oil saturation (in %).

[0096] Furthermore, in this embodiment, the logging curve that meets the preset sensitivity condition in the logging information is determined as the comparison curve, and the reservoir unit comparison (i.e., small layer comparison) of the tested well and the well to be tested is performed based on the comparison curve to obtain the comparison result. That is, the sand bodies deposited in the same period in space have similar logging curve characteristics, and the small layers of the well to be tested and the tested well are compared. Among them, it should be emphasized that the tested well is a well that has been put into production or a well with complete coring data, logging data, and relatively multiple logging series, and the relevant data of the tested well is relatively complete, but its completeness is less than that of the above-mentioned key wells. In addition, the logging curve that meets the preset sensitivity condition can include natural gamma curves, lateral, induction and gradient resistivity curves.

[0097] Finally, the reservoir unit lithology and curve change information in the obtained comparison results are obtained, and the reservoir type of each sequence is determined based on the reservoir unit lithology, the curve change information, the porosity and the oil saturation, so as to determine the oil and gas layers in each sequence using the reservoir type. In addition, as shown in Table 3, the reservoir interpretation evaluation standard for the target oil and gas exploration area can be established based on the various information data required for the final determination of the oil and gas layers, and the oil and gas layers in each sequence can be determined by the reservoir interpretation evaluation standard for the target oil and gas exploration area.

[0098] Table 3

[0099]

[0100] As can be seen from the above, the present application first obtains the first sequence interface set according to the characteristics of the well logging curve, and obtains the second sequence interface set according to the wellside seismic information and the well logging information. According to the preset rules, the target sequence interface set is determined from the two, and the isochronous stratigraphic framework is constructed and the sequence is calibrated. Under this framework, the rock electrical parameters and formation water resistivity of the sequence are determined by core data and the preset Archie formula, and the target porosity evaluation model is determined according to the three-porosity well logging curve and the core data to calculate the porosity. Then, the oil saturation is calculated according to the rock electrical parameters, formation water resistivity, porosity and the preset Archie formula, and the reservoir unit comparison is carried out based on the well logging curve, and the oil and gas layers in each sequence are identified by the comparison results, porosity and oil saturation. In this way, the present application can improve the accuracy and efficiency of oil and gas layer identification, thereby enhancing the user experience.

[0101] Combine the following Figure 6 , Figure 7 , Figure 8 as well as Fig. 9 The schematic diagram shown specifically illustrates the technical solution of the embodiment of the present application.

[0102] Specifically, in a specific embodiment, see Figure 6 and Figure 7 As shown, the accuracy of the present invention is verified by referring to the test and production results of the X2 well. Figure 6 For X1 well, Figure 7 Well X2, Well X1 is the target well (i.e. the tested well), Well X2 is the well to be evaluated (i.e. the well to be tested), both are located in the SH5 formation. Take the 30th layer 3020m of Well X2 as an example to calculate the porosity and oil saturation. The acoustic wave value AC at this depth point is 248μs / m, the deep induction resistivity value Rt is 3.8Ω·m, and the rock electrical parameters and formation water resistivity use the above values, i.e. a=1.0565, m=1.0752, b=1.0228, n=1.4942, Rw=0.073. Among them, the calculation process of the porosity of this layer is as follows:

[0103] ;

[0104] In addition, the calculation process of the water saturation of this layer is as follows:

[0105] ;

[0106] Therefore, the oil saturation of the layer can be obtained by calculating the porosity and water saturation of the layer. The calculation process of the oil saturation is as follows:

[0107] ;

[0108] Comparing the target well X1 and the well to be evaluated X2, it can be seen that the natural gamma curve has similar characteristics at about 3152m in X1 and 3005.5m in X2, the deep induction resistivity curve has similar characteristics at about 3138.5m in X1 and 2995m in X2, and the 4-meter gradient curve has similar characteristics at about 3158m in X1 and 3014m in X2. Overall, the logging curve characteristics of 2995-3064.4m in X2 and 3138-3208m in X1 are similar, indicating that they are sand bodies deposited in the same period, with strong contrast.

[0109] Based on the comparison of sand groups, the 3018-3052m section of Well X2 corresponds to the 3166-3186m section of Well X1 where industrial oil flow was obtained. The acoustic curve shows that the physical properties of Well X2 are better than those of Well X1, and the resistivity curve shows that the value of Well X2 is higher than that of Well X1, with good oil content. Its calculated porosity is between 10% and 18%, and its oil saturation is greater than 50%. According to the established comprehensive reservoir interpretation standard (that is, the reservoir interpretation and evaluation standard for the target oil and gas exploration area), Well X2 can be evaluated as an oil layer. In fact, Well X2 was tested to produce 10 tons of oil per day without water, and the production conclusion was that it was an oil layer.

[0110] In one embodiment, see Figure 8 As shown, the accuracy of the present invention is verified with reference to the test and production results of the X4 well. Figure 8 As shown in the figure, the comprehensive results of well X3 (left) and well X4 (right), the left side is the target well X3, and the right side is the well to be evaluated X4, both are located in the SH3 formation. By comparing the target well X3 and the well to be evaluated X4, it was found that the natural gamma, natural potential and deep (middle) induction curves at 4500-4504m, 4512-4558m and 4570-4610m of X3 well had similar characteristics with those at 4508-4512m, 4520-4548m and 4576-4620m of X4 well, respectively, indicating that they were sand bodies deposited in the same period. Well logging data showed that both X3 and X4 wells were pure sandstones with comparable sand body thickness, reservoir physical properties and oil content. The No. 4 and No. 7 layers of X3 well obtained industrial oil flow in testing, and the calculated porosity of X4 well was between 10% and 18%, with oil saturation greater than 50%. Based on the comparison results of the sand bodies of the two wells and the established comprehensive reservoir interpretation standards, the No. 3 and No. 6 layers of X4 well were evaluated as oil layers, the No. 4 and No. 7 layers were evaluated as oil-water layers, and the No. 5 and No. 8 layers were evaluated as water layers. The No. 3 and No. 6 layers of X4 well were perforated, producing 49 tons of oil per day without water, and the production conclusion was that it was an oil layer.

[0111] In one embodiment, see Fig. 9 As shown, the accuracy of the present invention is verified by referring to the test and production results of the X6 well. Fig. 9The X5 well (left) and X6 well (right) comprehensive results shown in the figure, the target well X5 well is on the left, and the well X6 well to be evaluated is on the right, both located in the SH8 formation. Comparing the target well X5 well and the well X6 well to be evaluated, it is found that the natural gamma and deep (middle) induction curves at 1792-1802m, 1810-1822m, and 1837-1860m of the X5 well have similar characteristics to those at 1936-1839m, 1840-1855m, and 1878-1900m of the X6 well, respectively, indicating that they are sand bodies deposited in the same period. Well logging data show that both Wells X5 and X6 are gray sandstone. The sand body of Well X6 is thicker and the deep-medium induction resistivity value is slightly higher. The physical properties of the two wells are comparable. Well X5 obtained industrial oil flow during testing. Based on the comparison results of the sand bodies of the two wells and the established comprehensive reservoir interpretation standards, Well X6's 27-30, 33, 35-37, and 39 layers were evaluated as oil layers. The test produced 16.1 tons of oil per day and was water-free. The conclusion of the production was that it was an oil layer.

[0112] Accordingly, see Fig.10 As shown, the embodiment of the present application provides a device for identifying oil and gas layers based on isochronous stratigraphic grid fine stratum comparison, comprising:

[0113] The interface determination module 11 is used to determine the first sequence interface set based on the logging curve characteristics in the target oil and gas exploration area, and to determine the second sequence interface set based on the wellside seismic information and the logging information;

[0114] A framework determination module 12 is used to determine a target sequence interface set in the first sequence interface set and the second sequence interface set based on a preset interface determination rule, and determine an isochronous stratigraphic framework using the target sequence interface set to calibrate sequences in the isochronous stratigraphic framework;

[0115] A porosity determination module 13 is used to determine the rock electrical parameters and formation water resistivity of each of the sequences under the isochronous stratigraphic framework based on core data and a preset Archie formula, and to determine a target porosity evaluation model for each of the sequences based on three-porosity logging curve information and the core data, so as to determine the porosity of the sequence using the target porosity evaluation model;

[0116] The oil and gas layer identification module 14 is used to determine the oil saturation of each of the sequences based on the rock electrical parameters, the formation water resistivity, the porosity and the preset Archie formula, and to compare reservoir units based on the logging curves, so as to identify the oil and gas layers in each of the sequences using the comparison results, the porosity and the oil saturation.

[0117] As can be seen from the above, the present application first obtains the first sequence interface set according to the characteristics of the well logging curve, and obtains the second sequence interface set according to the wellside seismic information and the well logging information. According to the preset rules, the target sequence interface set is determined from the two, and the isochronous stratigraphic framework is constructed and the sequence is calibrated. Under this framework, the rock electrical parameters and formation water resistivity of the sequence are determined by core data and the preset Archie formula, and the target porosity evaluation model is determined according to the three-porosity well logging curve and the core data to calculate the porosity. Then, the oil saturation is calculated according to the rock electrical parameters, formation water resistivity, porosity and the preset Archie formula, and the reservoir unit comparison is carried out based on the well logging curve, and the oil and gas layers in each sequence are identified by the comparison results, porosity and oil saturation. In this way, the present application can improve the accuracy and efficiency of oil and gas layer identification, thereby enhancing the user experience.

[0118] In a specific implementation, the interface determination module 11 specifically includes:

[0119] A standard profile construction unit, used to take a well containing drilling coring information and logging information as a key well, and modify the logging information using core data to construct a standard profile of the key well based on the modified logging information;

[0120] The first interface set determination unit is used to determine the first sequence interface set in the standard section based on the logging curve characteristics in the logging information.

[0121] In a specific implementation, the interface determination module 11 specifically includes:

[0122] A record determination unit, configured to determine a synthetic seismic record based on the acoustic wave curve and the density curve in the well logging information, and to modify the synthetic seismic record according to the wellside seismic information to obtain the synthetic seismic record that meets a preset similarity condition;

[0123] The second interface set determination unit is used to construct the seismic profile of the key well based on the modified logging information, and determine the second sequence interface set in the seismic profile using the seismic synthetic records that meet the preset similarity conditions.

[0124] In a specific implementation, the porosity determination module 13 specifically includes:

[0125] An information acquisition unit, used to acquire formation factors, porosity data, resistivity increase coefficient, water saturation and formation water information in the core data;

[0126] A rock electrical parameter determination unit, used to determine the rock electrical parameters of each of the sequences based on a preset Archie formula, the formation factors, the porosity data, the resistivity increase coefficient and the water saturation;

[0127] A first resistivity determination unit, configured to convert the ion mineralization into an equivalent NaCl mineralization based on an equivalent coefficient of the ion mineralization in the formation water information, and determine the resistivity of the formation water under experimental test conditions using the equivalent NaCl mineralization;

[0128] The second resistivity determination unit is used to determine the resistivity of the formation water under formation conditions based on a preset conversion formula and the resistivity of the formation water under the experimental test conditions.

[0129] In a specific implementation, the porosity determination module 13 specifically includes:

[0130] a depth information determination unit, configured to modify the depth information in the core data according to the depth information in the well logging information, so as to obtain target depth information in which the depth information of the core data is consistent with the depth information in the well logging information;

[0131] A relationship information determination unit, configured to obtain three-porosity logging curve information of a corresponding depth based on the target depth information, and to respectively determine the relationship information of the porosity data and the acoustic wave, density and neutron in the three-porosity logging curve information;

[0132] Each model determination unit is used to convert the relationship information into a relationship curve, and use the relationship curve and the porosity data to perform single-item fitting or multi-item fitting to obtain each porosity evaluation model;

[0133] The target model determination unit is used to determine the porosity evaluation model that meets the preset correlation condition among the porosity evaluation models as the target porosity evaluation model.

[0134] In a specific implementation, the oil and gas layer identification module 14 specifically includes:

[0135] The unit comparison unit is used to determine the logging curve that meets the preset sensitivity condition in the logging information as the comparison curve, and compare the reservoir units of the tested well and the well to be tested based on the comparison curve to obtain a comparison result.

[0136] In a specific implementation, the oil and gas layer identification module 14 specifically includes:

[0137] An information acquisition unit, used to obtain reservoir unit lithology and curve change information in the obtained comparison results;

[0138] The oil and gas layer identification unit is used to determine the reservoir type of each of the sequences based on the reservoir unit lithology, the curve change information, the porosity and the oil saturation, so as to determine the oil and gas layers in each of the sequences using the reservoir type.

[0139] Furthermore, the present application also discloses an electronic device. Fig.11 It is a structural diagram of an electronic device 20 shown according to an exemplary embodiment, and the content in the figure cannot be regarded as any limitation on the scope of use of this application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. Among them, the memory 22 is used to store a computer program, and the computer program is loaded and executed by the processor 21 to implement the relevant steps in the method for identifying oil and gas layers based on isochronous stratigraphic grid stratigraphic fine comparison disclosed in any of the aforementioned embodiments. In addition, the electronic device 20 in this embodiment may specifically be an electronic computer.

[0140] In this embodiment, the power supply 23 is used to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and the external device, and the communication protocol it follows is any communication protocol that can be applied to the technical solution of the present application, and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0141] In addition, the memory 22 as a carrier for resource storage may be a read-only memory, a random access memory, a disk or an optical disk, etc. The resources stored thereon may include an operating system 221, a computer program 222, etc., and the storage method may be temporary storage or permanent storage.

[0142] The operating system 221 is used to manage and control the hardware devices and computer program 222 on the electronic device 20, and can be Windows Server, Netware, Unix, Linux, etc. In addition to the computer program that can be used to complete the method for identifying oil and gas layers based on isochronous stratigraphic grid stratigraphic fine comparison performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 can further include computer programs that can be used to complete other specific tasks.

[0143] Furthermore, the present application also discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the aforementioned disclosed method for identifying oil and gas layers based on isochronous stratigraphic grid stratigraphic fine comparison is implemented. The specific steps of the method can be referred to the corresponding contents disclosed in the aforementioned embodiments, and will not be repeated here.

[0144] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0145] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0146] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0147] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article 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, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0148] The technical solution provided by the present application is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for general technicians in this field, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for identifying oil and gas layers based on isochronous stratigraphic framework and fine stratigraphic correlation, characterized in that: include: In the target oil and gas exploration area, a first sequence interface set is determined based on the characteristics of the well logging curve, and a second sequence interface set is determined based on the seismic information near the well and the well logging information; Determining a target sequence interface set from the first sequence interface set and the second sequence interface set based on a preset interface determination rule, and determining an isochronous stratigraphic framework using the target sequence interface set to calibrate sequences in the isochronous stratigraphic framework; Under the isochronous stratigraphic framework, the rock electrical parameters and formation water resistivity of each of the sequences are determined based on core data and a preset Archie formula, and a target porosity evaluation model of each of the sequences is determined based on three-porosity logging curve information and the core data, so as to determine the porosity of the sequence using the target porosity evaluation model; The oil saturation of each of the sequences is determined based on the rock electrical parameters, the formation water resistivity, the porosity and the preset Archie formula, and reservoir unit comparison is performed based on the logging curve to identify the oil and gas layers in each of the sequences using the comparison results, the porosity and the oil saturation.

2. The method for identifying oil and gas layers based on isochronous stratigraphic framework and fine stratigraphic correlation according to claim 1 is characterized in that: The determining of the first sequence interface set based on the logging curve characteristics comprises: A well including drilling coring information and logging information is used as a key well, and the logging information is modified using core data to construct a standard profile of the key well based on the modified logging information; In the standard section, a first sequence interface set is determined based on the logging curve characteristics in the logging information.

3. The method for identifying oil and gas layers based on isochronous stratigraphic framework and fine stratigraphic correlation according to claim 2 is characterized in that: The determining of the second sequence interface set based on wellside seismic information and well logging information comprises: Determine a synthetic seismic record based on the acoustic wave curve and the density curve in the well logging information, and modify the synthetic seismic record according to the wellside seismic information to obtain the synthetic seismic record that meets the preset similarity condition; A seismic profile of the key well is constructed based on the modified well logging information, and a second sequence interface set is determined in the seismic profile using the seismic synthetic records that meet the preset similarity conditions.

4. The method for identifying oil and gas layers based on isochronous stratigraphic framework and fine stratigraphic correlation according to claim 1 is characterized in that: The method of determining the rock electrical parameters and formation water resistivity of each sequence based on the core data and the preset Archie formula includes: Obtaining formation factors, porosity data, resistivity increase coefficient, water saturation and formation water information from the core data; Determine the rock electrical parameters of each of the sequences based on the preset Archie formula, the formation factors, the porosity data, the resistivity increase coefficient and the water saturation; Converting the ion mineralization into an equivalent NaCl mineralization based on an equivalent coefficient of the ion mineralization in the formation water information, and determining the formation water resistivity under experimental test conditions using the equivalent NaCl mineralization; The formation water resistivity under formation conditions is determined based on a preset conversion formula and the formation water resistivity under the experimental test conditions.

5. The method for identifying oil and gas layers based on isochronous stratigraphic framework and fine stratigraphic correlation according to claim 4 is characterized in that: The target porosity evaluation model for each sequence is determined based on the three-porosity logging curve information and the core data, including: Modifying the depth information in the core data according to the depth information in the well logging information to obtain target depth information in which the depth information of the core data is consistent with the depth information in the well logging information; Acquire three-porosity logging curve information of corresponding depth based on the target depth information, and respectively determine the relationship information of the porosity data and the acoustic wave, density and neutron in the three-porosity logging curve information; Converting the relationship information into a relationship curve, and performing single-item fitting or multi-item fitting using the relationship curve and the porosity data to obtain each porosity evaluation model; Among the porosity evaluation models, a porosity evaluation model that meets a preset correlation condition is determined as a target porosity evaluation model.

6. The method for identifying oil and gas layers based on isochronous stratigraphic grid fine stratum correlation according to any one of claims 1 to 5, characterized in that: The reservoir unit comparison based on the well logging curve includes: The logging curves satisfying the preset sensitivity conditions in the logging information are determined as comparison curves, and reservoir units of the tested wells and the wells to be tested are compared based on the comparison curves to obtain comparison results.

7. The method for identifying oil and gas layers based on isochronous stratigraphic framework and fine stratigraphic correlation according to claim 1 is characterized in that: The method of identifying the oil and gas layers in each of the sequences by using the obtained comparison results, the porosity and the oil saturation includes: Obtaining the reservoir unit lithology and curve change information in the comparison results; The reservoir type of each of the sequences is determined based on the reservoir unit lithology, the curve change information, the porosity and the oil saturation, so as to determine the oil and gas layers in each of the sequences using the reservoir type.

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