A method, apparatus, device and readable storage medium for stratigraphic division

Abstract

The application discloses a stratum division method, device and equipment and a readable storage medium, and relates to the technical field of oil and gas exploration and development. The method comprises the following steps: acquiring inversion resistivity data of different positions and different altitudes in a study area and well logging data of well logging points in the study area; performing first-order derivation on the inversion resistivity data to obtain first-order derivation data; determining top deep altitude data and bottom deep altitude data of a target layer according to the well logging data; performing position calibration on sawtooth points in the first-order derivation data corresponding to the well logging points according to the top deep altitude data and the bottom deep altitude data of the target layer to obtain calibrated positions; and determining a stratum layering line of the target layer according to the calibrated positions and the sawtooth points in the first-order derivation data. The stratum layering line of the target layer comprises a top layer layering line and a bottom layer layering line. The application further improves the accuracy of stratum division by using resistivity information.

Description

Technical Field

[0001] This invention relates to the technical field of oil and gas exploration and development, specifically to a stratigraphic division method, apparatus, equipment, and readable storage medium. Background Technology

[0002] With China's rapid economic growth, the demand for energy is increasing, and the depletion of domestic conventional oil and gas resources can no longer meet the needs of economic growth. Unconventional oil and gas resources are playing an increasingly important role in oil and gas exploration and development. Unconventional oil and gas reservoirs have significant overall development potential, but complex sedimentary patterns and intense diagenetic alteration result in strong reservoir heterogeneity and complex gas-water relationships. New technologies are needed to achieve a more accurate understanding of these gas-water relationships, thereby further improving the ultimate recovery rate of oil and gas reservoirs.

[0003] Wide-area electromagnetic (WEMA) exploration technology, as a type of electromagnetic exploration technology, has developed rapidly in recent years. It has seen comprehensive improvements in adaptability to exploration environments, flexibility in addressing geological problems, and resolution of geological targets, and its successful application in oil and gas exploration has gained widespread recognition. Due to its high sensitivity to fluids, it has been applied or shows great potential in various fields of exploration and development. WEMA, a type of electromagnetic method, involves emitting electromagnetic waves of different frequencies from the Earth's surface into the subsurface. Within a region not limited to the "far area," the electromagnetic field components are observed, and based on the derived surface wave calculation formula, a rigorous solution for the apparent resistivity is calculated, thus achieving an electromagnetic sounding method for detecting the resistivity of strata at different depths.

[0004] In the field of fluid identification, the resistivity of gas and water layers differs significantly. Due to its deep exploration depth, high accuracy, and sensitivity to fluids, the wide-area electromagnetic method (WEMA) is one of the most effective methods for identifying fluid properties. However, after identifying changes in the underground medium, it cannot accurately pinpoint the resistivity information to the target layer, making stratigraphic delineation difficult.

[0005] Existing technologies include methods for subsurface division using first-order curves. This method sums and averages the values ​​of data points at the same depth in a resistivity inversion profile to obtain the average soil resistivity at different depths. First-order differences are then performed on the average resistivity at two adjacent depths to obtain a first-order difference curve. This curve characterizes the difference in average resistivity between adjacent depths, and the stratification location of the soil can be determined based on the sawtooth points of the curve. However, this method is susceptible to subsurface shifts or errors due to data testing biases, resulting in low accuracy in stratigraphic division. Summary of the Invention

[0006] The technical problem this invention aims to solve is that existing stratigraphic delineation methods cannot accurately locate resistivity information to the target layer, resulting in low accuracy in stratigraphic delineation. The purpose of this invention is to provide a stratigraphic delineation method, apparatus, device, and readable storage medium that can improve the accuracy of stratigraphic delineation.

[0007] This invention is achieved through the following technical solution:

[0008] In a first aspect, the present invention provides a stratigraphic division method, the method comprising:

[0009] Acquire inversion resistivity data at different locations and altitudes in the study area, as well as well logging data from well logging points within the study area;

[0010] The first derivative of the inverted resistivity data is obtained by taking the first derivative.

[0011] Based on the well logging data, determine the top depth elevation data and bottom depth elevation data of the target layer;

[0012] Based on the top and bottom elevation data of the target layer, the sawtooth points in the first derivative data corresponding to the logging points are calibrated to obtain the calibration positions.

[0013] Based on the serrated points of the calibration location and the first-order derivative data, the stratigraphic division lines of the target layer are determined; the stratigraphic division lines of the target layer include the top layer division line and the bottom layer division line.

[0014] The above technical solution utilizes geological data, drilling data, and well logging data to understand the rock electrical characteristics of strata from top to bottom in the study area. Different strata exhibit varying rock electrical characteristics, with the greatest difference occurring at the interface between two strata. By leveraging the differences in rock electrical characteristics between each stratum and the adjacent strata, the first derivative of resistivity is calculated to locate stratigraphic interfaces, enabling the delineation of stratigraphic boundaries and further improving the accuracy of stratigraphic delineation using resistivity information.

[0015] Furthermore, the steps for obtaining the inverted resistivity data are as follows:

[0016] Acquire basic data for the study area, including electromagnetic field information, seismic data, geological data, well logging data, drilling data, and oil testing data;

[0017] A geoelectric model was established based on the basic data of the study area, and electromagnetic inversion was performed on the geoelectric model to obtain inverted resistivity data at different locations and altitudes in the study area.

[0018] Furthermore, based on the top and bottom elevation data of the target layer, the sawtooth points in the first-order derivative data corresponding to the logging points are calibrated to obtain the calibration positions, including:

[0019] Based on well logging data, determine the location data of well logging points;

[0020] Based on the location data of the logging points, determine the target derivative data corresponding to the logging points in the first-order derivative data;

[0021] Based on the top and bottom elevation data of the target layer, the serrated points in the target derivative data are calibrated to obtain the calibration positions; the calibration positions include the top depth position and the bottom depth position.

[0022] Furthermore, based on the top and bottom elevation data of the target layer, the positions of the jagged points in the target derivative data are calibrated to obtain the calibration positions, including:

[0023] Based on the top depth elevation data of the target layer, the position of the sawtooth points in the target derivative data is determined to obtain the top depth position;

[0024] The location of the sawtooth points in the target derivative data is determined by calibrating the bottom depth and elevation data of the target layer.

[0025] Furthermore, the top-level layering lines are obtained through the following steps:

[0026] Based on the top depth location, determine the first sawtooth zone where the sawtooth point in the first-order derivative data corresponding to the logging point is located; the first sawtooth zone is used to characterize the initial top layer division range of the target layer;

[0027] Based on the top depth position, determine the top depth position point corresponding to each saw tooth point on the first saw tooth band;

[0028] Connect the top depth points corresponding to each sawtooth point on the first sawtooth strip to obtain the top layer layering line of the target layer.

[0029] Furthermore, the bottom-level layer lines are obtained through the following steps:

[0030] Based on the bottom depth, determine the second sawtooth zone where the sawtooth point in the first-order derivative data corresponding to the logging point is located; the second sawtooth zone is used to characterize the initial bottom layer division range of the target layer;

[0031] Based on the bottom depth position, determine the bottom depth position points corresponding to each saw tooth point on the second saw tooth strip;

[0032] Connect the bottom depth points corresponding to each sawtooth point on the second sawtooth strip to obtain the bottom layer layering line of the target layer.

[0033] Furthermore, if the target sawtooth point is not obvious in the first sawtooth band, the top depth position point corresponding to the target sawtooth point is obtained through the following steps:

[0034] Determine the first and second sawtooth points on the first sawtooth strip that are adjacent to the target sawtooth point;

[0035] Based on the inverted resistivity data, determine the first elevation value corresponding to the top depth position of the first sawtooth point;

[0036] Based on the inverted resistivity data, determine the second elevation value corresponding to the top depth position of the second sawtooth point;

[0037] Calculate the average of the first and second altitude values ​​to obtain the corrected position;

[0038] The correction position is taken as the top depth position of the target sawtooth point.

[0039] Furthermore, after taking the first derivative of the inverted resistivity data to obtain the first derivative data, the method also includes:

[0040] Differentiate the first-order derivative data to obtain the second-order derivative data;

[0041] Based on the top and bottom elevation data of the target layer, the sawtooth points in the first-order derivative data corresponding to the logging points are calibrated to obtain the calibration positions, including:

[0042] Based on the top and bottom elevation data of the target layer, the sawtooth points in the second-order derivative data corresponding to the logging points are calibrated to obtain the calibration positions.

[0043] Based on the zigzag points of the calibration location and first-order derivative data, determine the stratigraphic division lines of the target layer, including:

[0044] Based on the zigzag points of the calibration location and the second-order derivative data, the stratigraphic division line of the target layer is determined.

[0045] Secondly, the present invention provides a stratigraphic division device, the device comprising:

[0046] The acquisition unit is used to acquire inversion resistivity data at different locations and altitudes in the study area, as well as well logging data from well logging points within the study area.

[0047] The first-order derivative unit is used to perform first-order derivative on the inverted resistivity data to obtain first-order derivative data.

[0048] The top and bottom elevation data determination unit is used to determine the top and bottom elevation data of the target layer based on well logging data.

[0049] The location calibration unit is used to calibrate the location of the sawtooth points in the first-order derivative data corresponding to the logging point based on the top depth elevation data and bottom depth elevation data of the target layer, and obtain the calibration location; the calibration location includes the top depth location and the bottom depth location.

[0050] The stratigraphic stratification line determination unit is used to determine the stratigraphic stratification line of the target layer based on the calibration location and the sawtooth points of the first-order derivative data; the stratigraphic stratification line of the target layer includes the top stratigraphic stratification line and the bottom stratigraphic stratification line.

[0051] Furthermore, the position calibration unit includes:

[0052] The first determining subunit is used to determine the location data of the logging point based on the logging data;

[0053] The second determining subunit is used to determine the target derivative data corresponding to the well logging point in the first-order derivative data based on the location data of the well logging point;

[0054] The calibration subunit is used to calibrate the position of the sawtooth points in the target derivative data based on the top depth elevation data and bottom depth elevation data of the target layer, and obtain the calibration position.

[0055] Furthermore, the stratigraphic unit for determining stratigraphic boundaries includes:

[0056] The top-level layering line determination sub-unit is used to determine the first sawtooth zone where the sawtooth points in the first-order derivative data corresponding to the logging point are located based on the top depth position; the first sawtooth zone is used to characterize the initial top-level division range of the target layer; the top depth position point corresponding to each sawtooth point on the first sawtooth zone is determined based on the top depth position; and the top depth position points corresponding to each sawtooth point on the first sawtooth zone are connected to obtain the top-level layering line of the target layer.

[0057] The bottom layer delineation subunit is used to determine the second sawtooth zone where the sawtooth points in the first-order derivative data corresponding to the logging point are located, based on the bottom depth position. The second sawtooth zone is used to characterize the initial bottom layer division range of the target layer. Based on the bottom depth position, the bottom depth position points corresponding to each sawtooth point on the second sawtooth zone are determined. And by connecting the bottom depth position points corresponding to each sawtooth point on the second sawtooth zone, the bottom layer delineation line of the target layer is obtained.

[0058] Furthermore, when the target sawtooth point is not obvious in the first sawtooth band of the top-level layer line determination sub-unit, the top depth position point corresponding to the target sawtooth point is obtained through the following process:

[0059] Determine the first and second sawtooth points on the first sawtooth strip that are adjacent to the target sawtooth point;

[0060] Based on the inverted resistivity data, determine the first elevation value corresponding to the top depth position of the first sawtooth point;

[0061] Based on the inverted resistivity data, determine the second elevation value corresponding to the top depth position of the second sawtooth point;

[0062] Calculate the average of the first and second altitude values ​​to obtain the corrected position;

[0063] The correction position is taken as the top depth position of the target sawtooth point.

[0064] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described stratigraphic division method.

[0065] Fourthly, the present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described stratigraphic division method.

[0066] Fifthly, the present invention also provides a computer program product, including a computer program / instruction that, when executed by a processor, implements the steps of the above-described stratigraphic division method.

[0067] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0068] This invention provides a method, apparatus, device, and readable storage medium for stratigraphic division. Compared to existing technologies that first homogenize data points at the same depth in different locations and then directly take the vertex of the sawtooth points of the first-order difference curve as the stratigraphic division line, this invention directly performs first-order differentiation on the original data. The resulting first-order difference curve is more consistent with the actual situation. Then, the top and bottom elevation data of the target layer are determined through well logging data. Based on the top and bottom elevation data of the target layer, the sawtooth points in the first-order derivative data corresponding to the well logging points are calibrated and their positions are corrected. Finally, the stratigraphic division line of the target layer is determined based on the calibrated positions and the sawtooth points of the first-order derivative data, which can improve the accuracy of stratigraphic division. Attached Figure Description

[0069] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0070] Figure 1 This is a flowchart of the stratigraphic division method according to Embodiment 1 of the present invention;

[0071] Figure 2 This is a schematic diagram of the inverted resistivity data in Embodiment 1 of the present invention;

[0072] Figure 3 This is a schematic diagram of the first-order derivative data in Embodiment 1 of the present invention;

[0073] Figure 4 This is a schematic diagram of the second-order derivative data in Embodiment 1 of the present invention;

[0074] Figure 5 This is a cross-sectional view of the first-order derivative data of Embodiment 1 of the present invention;

[0075] Figure 6 This is a cross-sectional view of the second-order derivative data in Embodiment 1 of the present invention;

[0076] Figure 7 This is a schematic diagram of the stratigraphic division lines in Embodiment 1 of the present invention;

[0077] Figure 8 This is a structural block diagram of the stratigraphic division device according to Embodiment 2 of the present invention. Detailed Implementation

[0078] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0079] Example 1

[0080] like Figure 1 As shown, the present invention provides a stratigraphic division method, the method comprising:

[0081] Acquire inversion resistivity data at different locations and altitudes in the study area, as well as well logging data from well logging points within the study area;

[0082] The first derivative of the inverted resistivity data is obtained by taking the first derivative.

[0083] Based on the well logging data, determine the top depth elevation data and bottom depth elevation data of the target layer;

[0084] Based on the top and bottom elevation data of the target layer, the sawtooth points in the first derivative data corresponding to the logging points are calibrated to obtain the calibration positions.

[0085] Based on the serrated points of the calibration location and the first-order derivative data, the stratigraphic division lines of the target layer are determined; the stratigraphic division lines of the target layer include the top layer division line and the bottom layer division line.

[0086] Understandably, the steps for obtaining inverted resistivity data are as follows:

[0087] Acquire basic data for the study area, including electromagnetic field information, seismic data, geological data, well logging data, drilling data, and oil testing data;

[0088] A geoelectric model was established based on the basic data of the study area, and electromagnetic inversion was performed on the geoelectric model to obtain inverted resistivity data at different locations and altitudes in the study area.

[0089] The inverted resistivity data is a wide-area inverted resistivity data sample. First, the three-dimensional seismic geological framework of the study area is extracted from the geological data to obtain the geological characteristics and structural features of the study area. A geological structure model is established based on the seismic data, and the geological structure model is divided into finite element elements. Then, the electrical characteristics of oil and gas wells in the study area are determined based on well logging data, drilling data, and oil testing data. Based on the electrical characteristics of oil and gas wells in the study area, electrical stratification is performed. The resistivity parameters of each physical stratum in the region are obtained based on electromagnetic field information. Based on the resistivity parameters and the geological structure model, a geoelectric model (geoelectric model) is established. The geoelectric model is used as a partitioning constraint condition for electromagnetic inversion to obtain the wide-area inverted resistivity data, i.e., the inverted resistivity data.

[0090] It should be noted that the principle for determining the inverted resistivity data is existing technology known to those skilled in the art, and will not be explained in detail here.

[0091] like Figure 2 As shown, the inverted resistivity data includes three aspects: point spacing, altitude, and wide-area resistivity. Different point spacings represent different locations, that is, the location of each point on each survey line when conducting wide-area measurement and laying out the data, represented by the distance from the first point on the survey line; multiple altitudes with the same point spacing represent the longitudinal depth value from top to bottom at a certain location; the wide-area resistivity corresponding to a certain point spacing and a certain altitude is the resistivity at a certain longitudinal depth at a certain location.

[0092] The above technical solution utilizes geological data, drilling data, and well logging data to understand the rock electrical characteristics of strata from top to bottom in the study area. Different strata exhibit varying rock electrical characteristics, with the greatest difference occurring at the interface between two strata. By leveraging the differences in rock electrical characteristics between each stratum and the adjacent strata, the first derivative of resistivity is calculated to locate stratigraphic interfaces, enabling the delineation of stratigraphic boundaries and further improving the accuracy of stratigraphic delineation using resistivity information.

[0093] Based on the inverted resistivity data, the first derivative (physical meaning of the first derivative: the range of resistivity variation in a certain segment of the formation at a given location) is calculated for the wide-area resistivity at a continuously varying depth along the vertical path, yielding the first-order difference curve for that point. The formula for calculating the first derivative is:

[0094] R x2 = (Y2-Y1) / (R) x2 -R x1 );

[0095] Where x is the point distance, Y1 represents the elevation of a certain stratum at point distance x, Y2 represents the elevation of the next closest stratum at point distance x, and R... x1 R represents the wide-area resistivity at elevation Y1 at a point distance x.x2 This represents the wide-area resistivity at elevation point Y2 at a distance x.

[0096] Using computer programming software and following a unified method, the first-order derivatives at each location point are calculated, generating first-order derivative data for the longitudinal section of the strata, such as... Figure 3 As shown, Figure 3 This is a data illustration for first-order derivative data. For example... Figure 5 As shown, based on the first-order derivative data, the derivative values ​​are magnified by the same factor to plot a high-resolution phase profile of the wide-area inverted resistivity (the magnification factor can be adjusted automatically using programming software, with the main goal being that the magnified high-resolution phase map clearly shows the magnitude of the change). The vertices of the sawtooth points are defined as follows: a rightward apex represents a positive change magnitude, and a leftward apex represents a negative change magnitude. The trend and magnitude of resistivity changes are clearly visible on the high-resolution phase map. The magnitude of the resistivity change represents the magnitude of the change in resistivity between the current and next strata. A positive change magnitude indicates an increase in resistivity from high to low altitude, representing a positive phase and indicating a transition from a relatively low-resistivity stratum to a relatively high-resistivity stratum. A negative change magnitude indicates a decrease in resistivity from low to high altitude, representing a negative phase and indicating a transition from a relatively high-low resistivity stratum to a relatively low-resistivity stratum.

[0097] It should be noted that the vertex of the sawtooth point refers to the vertex facing right or left.

[0098] In some embodiments of the present invention, such as Figure 4 and Figure 6 After obtaining the first-order derivative data by taking the first derivative of the inverted resistivity data, the method further includes:

[0099] Differentiate the first-order derivative data to obtain the second-order derivative data;

[0100] Based on the top and bottom elevation data of the target layer, the sawtooth points in the first-order derivative data corresponding to the logging points are calibrated to obtain the calibration positions, including:

[0101] Based on the top and bottom elevation data of the target layer, the sawtooth points in the second-order derivative data corresponding to the logging points are calibrated to obtain the calibration positions.

[0102] Based on the zigzag points of the calibration location and first-order derivative data, determine the stratigraphic division lines of the target layer, including:

[0103] Based on the zigzag points of the calibration location and the second-order derivative data, the stratigraphic division line of the target layer is determined.

[0104] Based on the first-order derivative data, the resistivity at a specific location is differentiated by a second derivative (the second derivative's physical meaning is the rate of change of resistivity in a certain section of the formation at that location) at continuously varying depths. This yields the second-order derivative data. It is understandable that, compared to the high-resolution phase profile of the resistivity phase profile derived from the first-order derivative data, the second-order derivative data shows a greater difference in resistivity between the top and bottom interfaces of the target layer, and better continuity at points laterally, resulting in a more accurate stratigraphic delineation of the target layer.

[0105] In some embodiments, multiple derivatives can be performed on the basis of the second-order derivative data until a high-resolution profile of the wide-area inverted resistivity phase is obtained, which shows the greatest difference in resistivity between the top and bottom interfaces of the target layer and the best continuity at each point in the lateral direction, so as to obtain a more accurate stratigraphic line of the target layer.

[0106] It should be noted that the process of second-order differentiation and multi-order differentiation is similar to that of first-order differentiation, and will not be explained in detail here.

[0107] In some embodiments of the present invention, such as Figure 7 As shown, based on the top and bottom elevation data of the target layer, the sawtooth points in the first-order derivative data corresponding to the logging points are calibrated to obtain the calibration positions, including:

[0108] Based on well logging data, determine the location data of well logging points;

[0109] Based on the location data of the logging points, determine the target derivative data corresponding to the logging points in the first-order derivative data;

[0110] Based on the top and bottom elevation data of the target layer, the positions of the sawtooth points in the target derivative data are calibrated to obtain the calibration positions.

[0111] Specifically, the calibration location includes the top depth location and the bottom depth location. Based on the top depth elevation data and bottom depth elevation data of the target layer, the locations of the jagged points in the target derivative data are calibrated to obtain the calibration location, including:

[0112] Based on the top depth elevation data of the target layer, the position of the sawtooth points in the target derivative data is determined to obtain the top depth position;

[0113] The location of the sawtooth points in the target derivative data is determined by calibrating the bottom depth and elevation data of the target layer.

[0114] Specifically, the stratigraphic lines of the target layer include the top stratigraphic line and the bottom stratigraphic line. The top stratigraphic line is obtained through the following steps:

[0115] Based on the top depth location, the first sawtooth zone where the sawtooth point in the first-order derivative data corresponding to the logging point is located is determined; the first sawtooth zone is used to characterize the initial top layer division range of the target layer;

[0116] Based on the top depth position, determine the top depth position points corresponding to each saw tooth point on the first saw tooth band;

[0117] Connect the top depth points corresponding to each sawtooth point on the first sawtooth strip to obtain the top layer layering line of the target layer.

[0118] Specifically, the bottom layer lines are obtained through the following steps:

[0119] Based on the bottom depth, determine the second sawtooth zone where the sawtooth point in the first-order derivative data corresponding to the logging point is located; the second sawtooth zone is used to characterize the initial bottom layer division range of the target layer;

[0120] Based on the bottom depth position, determine the bottom depth position points corresponding to each saw tooth point on the second saw tooth strip;

[0121] Connect the bottom depth positions corresponding to each sawtooth point on the second sawtooth strip to obtain the bottom layer layering line of the target layer.

[0122] Understandably, the location of the logging point (i.e., oil and gas well) is obtained during wide-area electromagnetic measurement, and then its location is mapped to the high-resolution phase profile of the wide-area inverted resistivity. Based on the obtained logging data, the formation depth and elevation data of the well are extracted, such as the top and bottom elevation data of the target layer. This allows the determination of the resistivity amplitude variation segment corresponding to the top elevation of the target layer in the high-resolution phase profile of the wide-area inverted resistivity at that point, as well as the resistivity amplitude variation point corresponding to the bottom elevation of the target layer (i.e., the specific sawtooth point on the difference curve at that point).

[0123] After confirming the resistivity amplitude variation points (specific sawtooth points on the difference curves) corresponding to the top and bottom depth elevations of the oil and gas well locations in the high-resolution phase profile of the wide-area inverted resistivity, based on the characteristic that the formation is a continuous whole, the elevation differences of the sawtooth points on the difference curves between adjacent points are small, and the formation thickness changes are stable. Therefore, the top and bottom sawtooth points of the oil and gas well locations are moved to the adjacent points on both sides, and the sawtooth points on the difference curves of each point are connected to obtain the formation division lines in the high-resolution phase profile of the wide-area inverted resistivity.

[0124] Taking a specific embodiment as an example, such as Figure 7As shown, the measured oil and gas well is located at 7600m on the wide-area inverted resistivity phase high-resolution profile. The top depth elevation of the target layer is -4304m and the bottom depth elevation is -4384m. The location of the oil and gas well and the corresponding top and bottom elevation points of the formation are found on the wide-area inverted resistivity phase high-resolution profile. It is found that the top depth elevation is located at 1 / 5 of the end of the sawtooth point and the bottom depth elevation is located at 1 / 4 of the end of the sawtooth point. According to this rule, the top and bottom sawtooth points of the oil and gas well location are moved to the adjacent points on both sides. The top boundary is the 1 / 5 of the end of the sawtooth point where the top depth elevation is located, and the bottom boundary is the 1 / 4 of the end of the sawtooth point where the bottom depth elevation is located. The stratigraphic layering correction is performed to determine the top layer layer line and the bottom layer layer line of the target layer, thereby determining the stratigraphic boundary line of the entire formation.

[0125] in, Figures 5 to 7 The horizontal axis represents distance, starting from 0, in meters (m); the vertical axis represents altitude, also in meters (m). It should be noted that for clarity, [the following text is incomplete and requires further context]. Figure 7 It is placed by rotating it 90 degrees to the left under normal circumstances.

[0126] In some embodiments of the present invention, when the target sawtooth point is not obvious in the first sawtooth band, the top depth position point corresponding to the target sawtooth point is obtained through the following steps:

[0127] Determine the first and second sawtooth points on the first sawtooth strip that are adjacent to the target sawtooth point;

[0128] Based on the inverted resistivity data, determine the first elevation value corresponding to the top depth position of the first sawtooth point;

[0129] Based on the inverted resistivity data, determine the second elevation value corresponding to the top depth position of the second sawtooth point;

[0130] Calculate the average of the first and second altitude values ​​to obtain the corrected position;

[0131] The correction position is taken as the top depth position of the target sawtooth point.

[0132] Understandably, the indistinctness of the target serration point indicates that it has disappeared or its shape is irregular, differing too much in shape and size from other serration points on the same serration zone, making it impossible to pinpoint the specific depth point on the target serration point. Since the first and second serration points can be correlated with first and second elevation values ​​after their depth points are pinpointed, the average of these two elevation values ​​can be used to determine the depth point of the target serration point, thus ensuring the continuity and accuracy of the stratigraphic division lines.

[0133] It should be noted that there are also cases where the saw teeth are not obvious in the second saw teeth band. This can also be corrected according to the method of the above embodiment, which will not be elaborated here.

[0134] In addition, it should be noted that the target sawtooth point can be a single sawtooth point or multiple consecutive sawtooth points. Both can be corrected according to the method described in the above embodiments, treating multiple sawtooth points as a single sawtooth point.

[0135] According to the stratigraphic division method of the present invention, compared with the existing method of first homogenizing data points of the same depth at different locations and then directly taking the vertex of the sawtooth point of the first-order difference curve as the stratigraphic division line, the present invention directly performs first-order differentiation on the original data. The resulting first-order difference curve is more consistent with the actual situation. Then, the top depth elevation data and bottom depth elevation data of the target layer are determined by well logging data. Based on the top depth elevation data and bottom depth elevation data of the target layer, the sawtooth points in the first-order derivative data corresponding to the well logging points are calibrated and specific position corrections are performed. Finally, the stratigraphic division line of the target layer is determined based on the calibrated position and the sawtooth points of the first-order derivative data, which can improve the accuracy of stratigraphic division.

[0136] Example 2

[0137] like Figure 8 As shown, the difference between this embodiment and Embodiment 1 is that this embodiment provides a stratigraphic division device, which includes:

[0138] The acquisition unit is used to acquire inversion resistivity data at different locations and altitudes in the study area, as well as well logging data from well logging points within the study area.

[0139] The first-order derivative unit is used to perform first-order derivative on the inverted resistivity data to obtain first-order derivative data.

[0140] The top and bottom elevation data determination unit is used to determine the top and bottom elevation data of the target layer based on well logging data.

[0141] The location calibration unit is used to calibrate the location of the sawtooth points in the first-order derivative data corresponding to the logging point based on the top depth elevation data and bottom depth elevation data of the target layer, and obtain the calibration location; the calibration location includes the top depth location and the bottom depth location.

[0142] The stratigraphic stratification line determination unit is used to determine the stratigraphic stratification line of the target layer based on the calibration location and the sawtooth points of the first-order derivative data; the stratigraphic stratification line of the target layer includes the top stratigraphic stratification line and the bottom stratigraphic stratification line.

[0143] like Figure 2As shown, the inverted resistivity data includes three aspects: point spacing, altitude, and wide-area resistivity. Different point spacings represent different locations, that is, the location of each point on each survey line when conducting wide-area measurement and laying out the data, represented by the distance from the first point on the survey line; multiple altitudes with the same point spacing represent the longitudinal depth value from top to bottom at a certain location; the wide-area resistivity corresponding to a certain point spacing and a certain altitude is the resistivity at a certain longitudinal depth at a certain location.

[0144] Geological data, drilling data, and well logging data can be used to understand the rock electrical characteristics of strata from top to bottom in the study area. Different strata exhibit different rock electrical characteristics, with the greatest difference occurring at the interface between two strata. By utilizing the differences in rock electrical characteristics between each stratum and the strata above and below, the first derivative of resistivity can be taken to locate the stratigraphic interfaces and delineate stratigraphic boundaries.

[0145] Based on the inverted resistivity data, the first derivative (physical meaning of the first derivative: the range of resistivity variation in a certain segment of the formation at a given location) is calculated for the wide-area resistivity at a continuously varying depth along the vertical path, yielding the first-order difference curve for that point. The formula for calculating the first derivative is:

[0146] R x2 = (Y2-Y1) / (R) x2 -R x1 );

[0147] Where x is the point distance, Y1 represents the elevation of a certain stratum at point distance x, Y2 represents the elevation of the next closest stratum at point distance x, and R... x1 R represents the wide-area resistivity at elevation Y1 at a point distance x. x2 This represents the wide-area resistivity at elevation point Y2 at a distance x.

[0148] Using computer programming software and following a unified method, the first-order derivatives at each location point are calculated, generating first-order derivative data for the longitudinal section of the strata, such as... Figure 3 As shown, Figure 3 This is a data illustration for first-order derivative data. For example... Figure 5As shown, based on the first-order derivative data, the derivative values ​​are magnified by the same factor to plot a high-resolution phase profile of the wide-area inverted resistivity (the magnification factor can be adjusted automatically using programming software, with the main goal being that the magnified high-resolution phase map clearly shows the magnitude of the change). The vertices of the sawtooth points are defined as follows: a rightward apex represents a positive change magnitude, and a leftward apex represents a negative change magnitude. The trend and magnitude of resistivity changes are clearly visible on the high-resolution phase map. The magnitude of the resistivity change represents the magnitude of the change in resistivity between the current and next strata. A positive change magnitude indicates an increase in resistivity from high to low altitude, representing a positive phase and indicating a transition from a relatively low-resistivity stratum to a relatively high-resistivity stratum. A negative change magnitude indicates a decrease in resistivity from low to high altitude, representing a negative phase and indicating a transition from a relatively high-low resistivity stratum to a relatively low-resistivity stratum.

[0149] Based on the first-order derivative data, the resistivity at a certain location point is subjected to multiple derivatives after the first-order derivative is obtained at a continuously varying depth in the longitudinal direction, until a high-resolution profile of the phase of the wide-area inverted resistivity is obtained, which shows the greatest difference in resistivity between the top and bottom interfaces of the target layer and the best continuity at each point in the lateral direction.

[0150] The location of the oil and gas well is obtained from the location points corresponding to the wide-area electromagnetic measurement, and then mapped to the location in the wide-area inversion resistivity phase high-resolution profile. Based on the obtained logging data, the formation depth and elevation data of the well are extracted, such as the top depth elevation data and bottom depth elevation data of the target layer. This allows us to confirm the resistivity amplitude change points corresponding to the top depth elevation of the target layer and the resistivity amplitude change points corresponding to the bottom depth elevation of the target layer in the wide-area inversion resistivity phase high-resolution profile at that point.

[0151] After confirming the resistivity amplitude variation points corresponding to the top and bottom depths and elevations of the strata at the location of the oil and gas well in the high-resolution phase profile of the wide-area inverted resistivity, based on the characteristic that the formation is a continuous whole, the elevation differences of the sawtooth points on the difference curves between adjacent points are small, and the formation thickness changes stably. Therefore, the top and bottom sawtooth points at the location of the oil and gas well are moved to the adjacent points on both sides, and the sawtooth points on the difference curves of each point are connected to obtain the strata division lines in the high-resolution phase profile of the wide-area inverted resistivity.

[0152] Taking a specific embodiment as an example, such as Figure 7As shown, the measured oil and gas well is located at 7600m on the wide-area inverted resistivity phase high-resolution profile. The top depth elevation of the target layer is -4304m and the bottom depth elevation is -4384m. The location of the oil and gas well and the corresponding top and bottom elevation points of the formation are found on the wide-area inverted resistivity phase high-resolution profile. It is found that the top depth elevation is located at 1 / 5 of the end of the sawtooth point and the bottom depth elevation is located at 1 / 4 of the end of the sawtooth point. According to this rule, the top and bottom sawtooth points of the oil and gas well location are moved to the adjacent points on both sides. The top boundary is the 1 / 5 of the end of the sawtooth point where the top depth elevation is located, and the bottom boundary is the 1 / 4 of the end of the sawtooth point where the bottom depth elevation is located. The stratigraphic layering correction is performed to determine the top layer layer line and the bottom layer layer line of the target layer, thereby determining the stratigraphic boundary line of the entire formation.

[0153] As a further implementation, the position calibration unit includes:

[0154] The first determining subunit is used to determine the location data of the logging point based on the logging data;

[0155] The second determining subunit is used to determine the target derivative data corresponding to the well logging point in the first-order derivative data based on the location data of the well logging point;

[0156] The calibration subunit is used to calibrate the position of the sawtooth points in the target derivative data based on the top depth elevation data and bottom depth elevation data of the target layer, and obtain the calibration position.

[0157] As a further implementation, the stratigraphic delineation unit includes:

[0158] The top-level layering line determination sub-unit is used to determine the first sawtooth zone where the sawtooth points in the first-order derivative data corresponding to the logging point are located based on the top depth position; the first sawtooth zone is used to characterize the initial top-level division range of the target layer; the top depth position point corresponding to each sawtooth point on the first sawtooth zone is determined based on the top depth position; and the top depth position points corresponding to each sawtooth point on the first sawtooth zone are connected to obtain the top-level layering line of the target layer.

[0159] The bottom layer delineation subunit is used to determine the second sawtooth zone where the sawtooth points in the first-order derivative data corresponding to the logging point are located, based on the bottom depth position. The second sawtooth zone is used to characterize the initial bottom layer division range of the target layer. Based on the bottom depth position, the bottom depth position points corresponding to each sawtooth point on the second sawtooth zone are determined. And by connecting the bottom depth position points corresponding to each sawtooth point on the second sawtooth zone, the bottom layer delineation line of the target layer is obtained.

[0160] As a further implementation, when the target sawtooth point is not obvious in the first sawtooth band of the top-level layer line determination sub-unit, the top depth position point corresponding to the target sawtooth point is obtained through the following process:

[0161] Determine the first and second sawtooth points on the first sawtooth strip that are adjacent to the target sawtooth point;

[0162] Based on the inverted resistivity data, determine the first elevation value corresponding to the top depth position of the first sawtooth point;

[0163] Based on the inverted resistivity data, determine the second elevation value corresponding to the top depth position of the second sawtooth point;

[0164] Calculate the average of the first and second altitude values ​​to obtain the corrected position;

[0165] The correction position is taken as the top depth position of the target sawtooth point.

[0166] The execution process of each unit can be carried out according to the steps of the stratigraphic division method in Example 1, and will not be described in detail in this example.

[0167] Meanwhile, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the aforementioned geological segregation method. The processor and the memory can be connected via a bus or other means.

[0168] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0169] The non-transient software program and instructions required to implement the stratigraphic division method of the above embodiments are stored in memory. When executed by the processor, the stratigraphic division method of the above embodiments is executed.

[0170] The electronic device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0171] Meanwhile, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above-described stratigraphic division method.

[0172] Meanwhile, the present invention also provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the above-described stratigraphic division method.

[0173] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0174] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0175] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0176] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0177] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for stratigraphic division, characterized in that, The method includes: Acquire inversion resistivity data at different locations and altitudes within the study area, as well as well logging data from well logging points within the study area; The inverted resistivity data is differentiated by first order to obtain the first-order derivative data; Based on the well logging data, determine the top depth elevation data and bottom depth elevation data of the target layer; Based on the top depth elevation data and the bottom depth elevation data of the target layer, the sawtooth points in the first-order derivative data corresponding to the logging point are calibrated to obtain the calibration position. Based on the calibration location and the sawtooth points of the first-order derivative data, the stratigraphic stratification line of the target layer is determined; the stratigraphic stratification line of the target layer includes the top stratigraphic stratification line and the bottom stratigraphic stratification line.

2. The stratigraphic division method according to claim 1, characterized in that, The steps for obtaining the inverted resistivity data are as follows: Acquire basic data for the study area, including electromagnetic field information, seismic data, geological data, well logging data, drilling data, and oil testing data; A geoelectric model was established based on the basic data of the study area, and electromagnetic inversion was performed on the geoelectric model to obtain inverted resistivity data at different locations and altitudes in the study area.

3. The stratigraphic division method according to claim 1, characterized in that, Based on the top depth elevation data and bottom depth elevation data of the target layer, the sawtooth points in the first-order derivative data corresponding to the logging point are calibrated to obtain the calibration positions, including: Based on the well logging data, the location data of the well logging point is determined; Based on the location data of the logging points, determine the target derivative data corresponding to the logging points in the first-order derivative data; Based on the top depth elevation data and the bottom depth elevation data of the target layer, the serrated points in the target derivative data are calibrated to obtain the calibration positions; the calibration positions include the top depth position and the bottom depth position.

4. The stratigraphic division method according to claim 3, characterized in that, Based on the top depth elevation data and the bottom depth elevation data of the target layer, the positions of the jagged points in the target derivative data are calibrated to obtain the calibrated positions, including: Based on the top depth elevation data of the target layer, the position of the sawtooth points in the target derivative data is determined to obtain the top depth position; Based on the bottom depth and elevation data of the target layer, the serrated points in the target derivative data are located to obtain the bottom depth position.

5. A stratigraphic division method according to claim 3, characterized in that, The top-level layer line is obtained through the following steps: Based on the top depth position, the first sawtooth zone where the sawtooth point in the first-order derivative data corresponding to the logging point is located is determined; the first sawtooth zone is used to characterize the initial top layer division range of the target layer; Based on the top depth position, determine the top depth position point corresponding to each saw tooth point on the first saw tooth strip; Connect the top depth points corresponding to each sawtooth point on the first sawtooth strip to obtain the top layer layering line of the target layer.

6. The stratigraphic division method according to claim 3, characterized in that, The underlying layer lines are obtained through the following steps: Based on the bottom depth location, determine the second sawtooth zone where the sawtooth point in the first-order derivative data corresponding to the logging point is located; the second sawtooth zone is used to characterize the initial bottom layer division range of the target layer; Based on the bottom depth position, determine the bottom depth position point corresponding to each saw tooth point on the second saw tooth strip; Connect the bottom depth positions corresponding to each sawtooth point on the second sawtooth strip to obtain the bottom layer layering line of the target layer.

7. A stratigraphic division method according to claim 5, characterized in that, When the target sawtooth point is not obvious in the first sawtooth band, the top depth position point corresponding to the target sawtooth point is obtained through the following steps: Determine the first and second sawtooth points on the first sawtooth strip that are adjacent to the target sawtooth point; Based on the inverted resistivity data, determine the first elevation value corresponding to the top depth position at the first sawtooth point; Based on the inverted resistivity data, determine the second elevation value corresponding to the top depth position at the second sawtooth point; Calculate the average of the first altitude value and the second altitude value to obtain the corrected position; The corrected position is taken as the top depth position of the target sawtooth point.

8. The stratigraphic division method according to claim 1, characterized in that, After obtaining the first-order derivative data by performing first-order differentiation on the inverted resistivity data, the method further includes: Differentiating the first-order derivative data yields the second-order derivative data; Based on the top depth elevation data and bottom depth elevation data of the target layer, the sawtooth points in the first-order derivative data corresponding to the logging point are calibrated to obtain the calibration positions, including: Based on the top depth elevation data and the bottom depth elevation data of the target layer, the sawtooth points in the second-order derivative data corresponding to the logging point are calibrated to obtain the calibrated positions. Based on the calibration location and the sawtooth points of the first-order derivative data, the stratigraphic division line of the target layer is determined, including: Based on the calibration location and the sawtooth points of the second-order derivative data, the stratigraphic division line of the target layer is determined.

9. A stratigraphic division device, characterized in that, The device includes: The acquisition unit is used to acquire inversion resistivity data at different locations and altitudes in the study area, as well as well logging data of well logging points in the study area. A first-order derivative unit is used to perform first-order derivative on the inverted resistivity data to obtain first-order derivative data. The top and bottom elevation data determination unit is used to determine the top depth elevation data and bottom depth elevation data of the target layer based on the well logging data. The location calibration unit is used to calibrate the location of the sawtooth points in the first-order derivative data corresponding to the logging point based on the top depth elevation data and the bottom depth elevation data of the target layer, so as to obtain the calibration location; the calibration location includes the top depth location and the bottom depth location. The stratigraphic stratification line determination unit is used to determine the stratigraphic stratification line of the target layer based on the calibration location and the sawtooth points of the first-order derivative data; the stratigraphic stratification line of the target layer includes the top stratigraphic stratification line and the bottom stratigraphic stratification line.

10. A stratigraphic division device according to claim 9, characterized in that, The position calibration unit includes: The first determining subunit is used to determine the location data of the logging point based on the logging data; The second determining subunit is used to determine the target derivative data corresponding to the well logging point in the first-order derivative data based on the location data of the well logging point; The calibration subunit is used to calibrate the position of the sawtooth points in the target derivative data based on the top depth elevation data and the bottom depth elevation data of the target layer, so as to obtain the calibration position.

11. A stratigraphic division device according to claim 9, characterized in that, The stratigraphic stratification line determination unit includes: The top-layer delineation subunit is used to determine the first sawtooth band where the sawtooth points in the first-order derivative data corresponding to the logging point are located, based on the top depth position; the first sawtooth band is used to characterize the initial top-layer division range of the target layer; the top depth position points corresponding to each sawtooth point on the first sawtooth band are determined based on the top depth position; and the top depth position points corresponding to each sawtooth point on the first sawtooth band are connected to obtain the top-layer delineation line of the target layer.

12. A stratigraphic division device according to claim 11, characterized in that, The stratigraphic stratification line determination unit also includes: The bottom layer delineation subunit is used to determine the second sawtooth band where the sawtooth point in the first-order derivative data corresponding to the logging point is located, based on the bottom depth position; the second sawtooth band is used to characterize the initial bottom layer division range of the target layer; the bottom depth position point corresponding to each sawtooth point on the second sawtooth band is determined based on the bottom depth position; and the bottom depth position points corresponding to each sawtooth point on the second sawtooth band are connected to obtain the bottom layer delineation line of the target layer.

13. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements a stratigraphic division method as described in any one of claims 1 to 8.

14. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements a stratigraphic division method as described in any one of claims 1 to 8.

15. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of a stratigraphic division method as described in any one of claims 1 to 8.

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