Method, apparatus, device, medium and product for well logging environment correction

Abstract

The present application provides a method, device, equipment, medium and product for well logging environment correction, belonging to the technical field of oil and gas exploration and development. The technical solution provided by the embodiments of the present application differentiates shale sections and sandstone sections according to the depth curve of well logging and the corresponding first spontaneous potential curve; based on the borehole diameter curve of the collapsed section of the shale section, a first density change relationship is obtained to correct the density curve of the entire well section; on the basis of the above correction, based on the porosity curve of the sandstone section, a second density change relationship is obtained to correct the density curve of the sandstone section; by combining the curves corrected twice, overall correction of the entire well section and key correction of the sandstone section are realized, achieving accurate correction of the density curves of sandstone and shale in the case of poor quality of conventional well logging curves, large-area borehole diameter collapse, no standard layer and standard curves, thereby effectively improving the quality of well logging data.

Description

Technical Field

[0001] This application relates to the technical field of oil and gas exploration and development, and particularly relates to a method, device, equipment, medium and product for well logging environment correction. Background Art

[0002] In the process of oil and gas exploration and development, well logging curves have always been one of the important means of oil and gas exploration. Especially in aspects such as seismic synthetic record calibration, high-quality reservoir prediction, and hydrocarbon detection, the accuracy of well logging curves can directly affect the reliability evaluation of data. During conventional well logging, due to environmental factors such as differences in compaction of the original formation, drill bit vibration, and long mud immersion time, wellbore formation collapse has become a common phenomenon. Usually, in the case of less or local wellbore collapse, the influence of these factors on well logging curves is relatively small, and the environmental correction method can be used to eliminate them. However, in the case of severe wellbore collapse, it directly leads to distortion of well logging data such as density and acoustic travel time, making it difficult to truly reflect the actual situation of the formation, and unable to reasonably carry out related work such as well logging interpretation, horizon calibration, rock physics modeling, reservoir prediction, and hydrocarbon detection, thus unable to meet the requirements of fine exploration production.

[0003] With the continuous deepening of exploration work, high-quality acoustic and density well logging curves play an increasingly important role in the production process. Therefore, environmental correction for wellbore collapse has become an essential important link in the well logging correction process.

[0004] Currently, the more commonly used curve correction methods mainly include two types: one is to perform fitting based on the empirical formula Gardner equation, and the other is to perform multiple fitting using conventional well logging curves (natural gamma, deep resistivity, neutron, etc. curves). However, the above two correction methods are usually only applicable to areas with less severe or moderately severe wellbore collapse, and are not applicable to areas with large-scale severe wellbore collapse. Moreover, only mudstone is corrected, ignoring the correction of sandstone curves that are more sensitive to the reservoir, and the quality of the corrected well logging data is not high. Summary of the Invention

[0005] The embodiments of this application provide a method, device, equipment, medium and product for well logging environment correction, which can accurately correct the density curves of sandstone and mudstone in the case of poor quality of conventional well logging curves, large-scale wellbore collapse, no standard layer, and standard curves, thereby effectively improving the quality of well logging data. The technical solution is as follows:

[0006] On the one hand, a method for well logging environment correction is provided, and the method includes:

[0007] Obtain the depth curve of well logging and the corresponding first spontaneous potential curve;

[0008] Based on this depth curve, the first spontaneous potential curve is corrected to obtain a corrected second spontaneous potential curve. The second spontaneous potential curve between the minimum and maximum values of the first spontaneous potential curve corresponds to the shale section, and the other second spontaneous potential curves correspond to the sandstone section;

[0009] Based on the borehole diameter curve in the collapse section, the first density curve, and the measured density value of the shale core, a first density change relationship is obtained;

[0010] Based on this first density change relationship, the density curve of the entire well section is corrected to obtain a corrected second density curve;

[0011] Based on the total nuclear magnetic porosity and the porosity of the effective shale section, the porosity curve of the sandstone section is calculated;

[0012] Based on this second density curve and the measured density value of the sandstone core, the relative change in the second density of the collapse section is calculated;

[0013] Based on the porosity curve of this sandstone section and this relative change in the second density, fitting is performed to obtain a second density change relationship;

[0014] Based on this second density change relationship, the density curve of the sandstone section is corrected to obtain a corrected third density curve;

[0015] Combining this second density curve and this third density curve, a fourth density curve is obtained, where the shale section corresponds to the second density curve and the sandstone section corresponds to the third density curve.

[0016] In a possible implementation manner, obtaining the first density change relationship based on the borehole diameter curve in the collapse section, the first density curve, and the measured density value of the shale core includes:

[0017] Based on the borehole diameter curve in the collapse section, the diameter expansion rate of the shale section is calculated;

[0018] Based on the first density curve in the collapse section and the measured density value of the shale core, the relative change in the first density of the collapse section is calculated;

[0019] Based on this diameter expansion rate and this relative change in the first density, fitting is performed to obtain a first density change relationship.

[0020] In a possible implementation manner, the method further includes:

[0021] Using a large-scale median filtering method to filter this diameter expansion rate and this relative change in the first density.

[0022] In a possible implementation manner, the method further includes:

[0023] Adopt a large-scale median filtering method to filter the porosity curve of this sandstone section.

[0024] In a possible implementation manner, the method further includes:

[0025] Verify the rationality of this fourth density curve based on well logging data and seismic data.

[0026] On the one hand, a device for well logging environment correction is provided. The device includes:

[0027] A data acquisition module for acquiring the depth curve of well logging and the corresponding first spontaneous potential curve;

[0028] A data processing module for correcting the first spontaneous potential curve based on the depth curve to obtain a corrected second spontaneous potential curve. The second spontaneous potential curve between the minimum value and the maximum value of the first spontaneous potential curve corresponds to the shale section, and other second spontaneous potential curves correspond to the sandstone section;

[0029] A full well section module for obtaining a first density change relationship based on the borehole diameter curve of the caving section, the first density curve, and the measured density value of shale core sampling;

[0030] The full well section module is also used for correcting the density curve of the full well section based on the first density change relationship to obtain a corrected second density curve;

[0031] A sandstone module for calculating the porosity curve of the sandstone section based on the total nuclear magnetic porosity and the porosity of the effective shale section;

[0032] The sandstone module is also used for calculating the relative change amount of the second density in the caving section based on the second density curve and the measured density value of sandstone core sampling;

[0033] The sandstone module is also used for fitting the porosity curve of the sandstone section and the relative change amount of the second density to obtain a second density change relationship;

[0034] The sandstone module is also used for correcting the density curve of the sandstone section based on the second density change relationship to obtain a corrected third density curve;

[0035] A combination module for combining the second density curve and the third density curve to obtain a fourth density curve, where the shale section corresponds to the second density curve and the sandstone section corresponds to the third density curve.

[0036] In a possible implementation manner, the full well section module is used for:

[0037] Calculate the hole enlargement rate of the shale section based on the borehole diameter curve of the caving section;

[0038] Based on the first density curve of the caving section and the measured density value of the mudstone core, calculate the relative change in the first density of the caving section;

[0039] Based on the diameter enlargement rate and the relative change in the first density, perform fitting to obtain the relationship of the change in the first density.

[0040] On the one hand, an electronic device is provided, including:

[0041] One or more processors;

[0042] One or more memories for storing executable instructions of the one or more processors;

[0043] Wherein, the one or more processors are configured to execute the instructions to implement the method for well logging environment correction provided in any of the above possible implementation manners.

[0044] On the one hand, a storage medium is provided. When the instructions in the storage medium are executed by the processor of the electronic device, the electronic device can execute the method for well logging environment correction provided in any of the above possible implementation manners.

[0045] On the one hand, a computer program product is provided, including computer instructions, and when the computer instructions are executed by the processor, the method for well logging environment correction provided in any of the above possible implementation manners is implemented.

[0046] The technical solution provided in the embodiments of the present application distinguishes the mudstone section and the sandstone section according to the depth curve of well logging and the corresponding first spontaneous potential curve; based on the caving section well diameter curve of the mudstone section, obtains the relationship of the change in the first density, and corrects the density curve of the entire well section; on the basis of the above correction, based on the porosity curve of the sandstone section, obtains the relationship of the change in the second density, and corrects the density curve of the sandstone section; by combining the curves of the two corrections, realizes the overall correction of the entire well section and the key correction of the sandstone section. This technical solution is based on the double-trend control of calculating the well diameter caving rate and porosity, superimposes the details of the relative change in density, and realizes the accurate correction of the density curves of sandstone and mudstone in the case of poor quality of conventional well logging curves, large-area well diameter caving, no standard layer, and standard curves, thereby effectively improving the quality of well logging data. Description of the Drawings

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings.

[0048] Figure 1 is a flowchart of a method for well logging environment correction provided by an embodiment of the present application;

[0049] Figure 2 is a flowchart of a method for well logging environment correction provided by an embodiment of the present application;

[0050] Figure 3 is Figure 2 a technical idea flowchart of the corresponding method for well logging environment correction;

[0051] Figure 4 is a synthetic log calibration comparison chart of a borehole diameter collapse before, multiple regression fitting, and the method for well logging environment correction provided by an embodiment of the present application;

[0052] Figure 5 is a schematic structural diagram of a device for well logging environment correction provided by an embodiment of the present application;

[0053] Figure 6 is a schematic structural diagram of an electronic device provided by an embodiment of the present application. Detailed implementation manners

[0054] To make the objectives, technical solutions, and advantages of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the accompanying drawings.

[0055] Figure 1 is a flowchart of a method for well logging environment correction provided by an embodiment of the present application. Please refer to Figure 1 , this method can be applied to an electronic device, and the method includes:

[0056] 101. Obtain the depth curve of the well logging and the corresponding first spontaneous potential curve.

[0057] 102. Based on the depth curve, correct the first spontaneous potential curve to obtain a corrected second spontaneous potential curve.

[0058] Among them, the second spontaneous potential curve between the minimum value and the maximum value of the first spontaneous potential curve corresponds to the shale section, and the other second spontaneous potential curves correspond to the sandstone section.

[0059] 103. Based on the borehole diameter curve in the collapsed section, the first density curve, and the measured density value of the shale core, obtain a first density change relationship.

[0060] 104. Based on the first density change relationship, correct the density curve of the entire well section to obtain a corrected second density curve.

[0061] 105. Calculate the porosity curve of the sandstone section based on the total nuclear magnetic porosity and the porosity of the effective shale section.

[0062] 106. Calculate the relative change in the second density of the caving section based on the second density curve and the measured density value of the sandstone core.

[0063] 107. Fit the porosity curve of the sandstone section and the relative change in the second density to obtain the relationship of the change in the second density.

[0064] 108. Correct the density curve of the sandstone section based on the relationship of the change in the second density to obtain the corrected third density curve.

[0065] 109. Combine the second density curve and the third density curve to obtain the fourth density curve, where the shale section corresponds to the second density curve and the sandstone section corresponds to the third density curve.

[0066] The technical solution provided by the embodiment of the present application distinguishes the shale section and the sandstone section according to the depth curve of the well logging and the corresponding first spontaneous potential curve; based on the wellbore diameter curve of the caving section in the shale section, obtain the relationship of the first density change, and correct the density curve of the entire well section; on the basis of the above correction, based on the porosity curve of the sandstone section, obtain the relationship of the second density change, and correct the density curve of the sandstone section; by combining the curves corrected twice, realize the overall correction of the entire well section and the key correction of the sandstone section. This technical solution is based on the double trend control of calculating the wellbore diameter caving rate and porosity, and superimposes the relative change details of the density, so as to accurately correct the density curves of sandstone and shale in the case of poor quality of conventional well logging curves, large-area wellbore caving, no standard layer and standard curve, thereby effectively improving the quality of well logging data.

[0067] In a possible implementation manner, obtaining the relationship of the first density change based on the wellbore diameter curve of the caving section, the first density curve, and the measured density value of the shale core includes:

[0068] Calculate the hole enlargement rate of the shale section based on the wellbore diameter curve of the caving section.

[0069] Calculate the relative change in the first density of the caving section based on the first density curve of the caving section and the measured density value of the shale core.

[0070] Fit the hole enlargement rate and the relative change in the first density to obtain the relationship of the first density change.

[0071] In a possible implementation manner, the method further includes:

[0072] Use the large-scale median filtering method to filter the hole enlargement rate and the relative change in the first density.

[0073] In a possible implementation, the method further includes:

[0074] Adopt a large-scale median filtering method to filter the porosity curve of the sandstone section.

[0075] In a possible implementation, the method further includes:

[0076] Verify the rationality of the fourth density curve based on well logging data and seismic data.

[0077] All of the above optional technical solutions can be combined arbitrarily to form optional embodiments of the present application, which will not be elaborated herein one by one.

[0078] Figure 2 It is a flowchart of a well logging environment correction method provided by an embodiment of the present application. This method can be applied to an electronic device. Figure 3 is Figure 2 The technical idea flowchart of the corresponding well logging environment correction method. Please refer to Figure 2 and Figure 3 , and this method includes:

[0079] 201. Obtain the depth curve of the well logging and the corresponding first spontaneous potential curve.

[0080] Among them, the depth curve represents the corresponding relationship between the rock formation and the depth. For the research area, due to reasons such as borehole collapse, the gamma curve reflecting the sand-shale relationship is distorted. Therefore, in this embodiment, the spontaneous potential curve (SP curve), which is also sensitive to the distinction between sandstone and shale, is used for fine lithology division. In the mudstone formation, the shape of the SP curve is close to a straight line. However, due to the influence of formation water and mud filtrate, there is a phenomenon of mudstone baseline drift in the SP curve. Therefore, step 202 is used to remove the influence of the mudstone baseline on the SP curve.

[0081] 202. Based on the depth curve, correct the first spontaneous potential curve to obtain a corrected second spontaneous potential curve.

[0082] Among them, the second spontaneous potential curve located between the minimum value and the maximum value of the first spontaneous potential curve corresponds to the mudstone section, and other second spontaneous potential curves correspond to the sandstone section.

[0083] Specifically, this step 202 includes: based on the intersection relationship between the depth curve and the SP curve, that is, the characteristics of the mudstone changing with depth, pick up the depth values and SP values on the mudstone section in different layers, use polynomials for fitting to obtain the baseline drift amount ΔSP of the SP curve (see the following relational expression 1), and perform mutual operations on the SP curve and the ΔSP curve for correction to obtain SP’ (see the following relational expression 2), ensuring that the SP’ curve approaches a straight line in the mudstone formation.

[0084] ΔSP = A * Depth 2 + B * Depth + C Relationship 1

[0085] SP’ = (SP, ΔSP) Relationship 2

[0086] Wherein, SP represents the first spontaneous potential value of the formation, V;

[0087] ΔSP represents the baseline drift value, V;

[0088] SP’ represents the corrected second spontaneous potential value, V;

[0089] A, B, and C are coefficients to be determined, dimensionless;

[0090] Depth represents the logging depth, m.

[0091] When applying this embodiment to an electronic device, the lithology curve can be marked based on a programming language to more clearly distinguish mudstone and sandstone. In the programming language, according to the result of the corrected SP’, the following conditional statement is applied to finely divide sandstone and mudstone.

[0092] If

[0093] SP’ > SP Mud_min and SP’ < SP Mud_max

[0094] Lithology = 1

[0095] else

[0096] Lithology = 2

[0097] Wherein, SP Mud_min represents the minimum value of the spontaneous potential value of the given mudstone, V;

[0098] SP Mud_max represents the maximum value of the spontaneous potential value of the given mudstone, V;

[0099] Lithology represents the lithology curve;

[0100] 1 represents mudstone;

[0101] 2 represents sandstone.

[0102] In this embodiment, by analyzing the relationship between mudstone and sandstone, it is known that:

[0103] 1) Seismic data shows that the channel sand bodies in this area exhibit strong amplitude reflection characteristics of "bright spots", indicating that there is an impedance change relationship between the channel sand bodies and the surrounding rocks (mudstones), which is contradictory to the view of impedance superposition of sandstones and mudstones from the results of log crossplots. Through comprehensive analysis of logs and seismic data, since the phenomenon of borehole diameter collapse is relatively common in this area, it seriously affects the quality of log curves, especially the density curve.

[0104] 2) Comparing synthetic seismograms calibrated with logs of different collapse degrees, those with high impedance of mudstone and low impedance of sandstone have the best calibration effect. At the same time, pure sandstone and pure mudstone intersections with better borehole diameter conditions and different burial depths are selected, which also have the characteristics of high impedance of mudstone and low impedance of sandstone.

[0105] Next, since the density log curve in the study area is seriously affected by borehole diameter collapse, in order to quantitatively characterize the influence of hole enlargement on density logging, two concepts, namely hole enlargement rate and relative density change amount, are introduced.

[0106] 203. Based on the borehole diameter curve in the collapsed section, calculate the hole enlargement rate of the mudstone section.

[0107] Specifically, the hole enlargement rate can be calculated according to the following relational expression 3.

[0108] α = (CAL - BITS) / BITS Relational expression 3

[0109] Where, α is the hole enlargement rate, %;

[0110] CAL is the borehole diameter, m;

[0111] BITS is the bit diameter, m.

[0112] 204. Based on the first density curve in the collapsed section and the measured density value of mudstone core, calculate the first relative density change amount of the collapsed section.

[0113] Specifically, the first relative density change amount can be calculated according to the following relational expression 4.

[0114] Δρ1 = (DEN1 取芯 - DEN 实测 ) Relational expression 4

[0115] Where, Δρ1 is the first relative density change amount, g / cm 3 ;

[0116] DEN1 取芯 is the density value of mudstone core, g / cm 3 ;

[0117] DEN 实测 is the measured density value, g / cm 3 .

[0118] 205. Apply the large-scale median filtering method to filter the diameter expansion rate and the relative change in the first density.

[0119] Specifically, apply the large-scale median filtering method to filter the diameter expansion rate α and the relative change in the first density Δρ to obtain the filtered diameter expansion rate α1 and the fitted relative change in the first density Δρ1. The purpose of the above median filtering is to eliminate the influence of high-frequency noises such as spike pulses, steps, ramps, random noises, and non-stratum factors, remove the fine change characteristics inside the curve, and retain the large stratum trend background, laying a foundation for curve fitting.

[0120] 206. Fit based on the filtered diameter expansion rate and the relative change in the first density to obtain the relationship formula for the change in the first density.

[0121] Among them, the relationship formula for the change in the first density can be expressed by the following relationship formula 5.

[0122] △ρ1 = D * α1 + E Relationship formula 5

[0123] Among them, △ρ1 is the relative change in the first density, g / cm 3 ;

[0124] α1 is the filtered diameter expansion rate, dimensionless;

[0125] D and E are coefficients to be obtained, dimensionless.

[0126] 207. Based on the relationship formula for the change in the first density, correct the density curve of the entire well section to obtain the corrected second density curve.

[0127] Among them, the second density curve is also the correction result of the density curve of the entire well section, and the expression of the second density curve can be expressed by the following relationship formula 6.

[0128] ρ 全 = D * α1 + E + DEN 实测 Relationship formula 6

[0129] Among them, ρ 全 represents the second density obtained after correcting the entire well section, g / cm 3 ;

[0130] α1 is the filtered diameter expansion rate, dimensionless;

[0131] D and E are coefficients to be obtained, dimensionless;

[0132] DEN 实测 is the measured density value, g / cm 3 .

[0133] Next, based on the previously established relative relationship between sandstone and mudstone, on the background of wellbore collapse in the entire well section, the sandstone trend is corrected with emphasis. Two concepts, namely sandstone porosity measure and relative change in the second density, which are highly correlated with sandstone density, are introduced.

[0134] 208. Calculate the porosity curve of the sandstone section based on the total nuclear magnetic porosity and the porosity of the effective mudstone section.

[0135] Among them, the total nuclear magnetic porosity is the porosity measured based on nuclear magnetic resonance logging technology, and the porosity of the sandstone section can be expressed by the following relational expression 7.

[0136] β = Por - Por sh Relational expression 7

[0137] Among them, β is the porosity of the sandstone section, %;

[0138] Por is the total nuclear magnetic porosity, %;

[0139] Por sh is the porosity of the effective mudstone section, %.

[0140] 209. Calculate the relative change in the second density of the collapsed section based on this second density curve and the measured density value of the sandstone core.

[0141] Among them, the relative change in the second density can be expressed by the following relational expression 8.

[0142] Δ ρ2 =(ρ 全 - DEN2 取芯 ) Relational expression 8

[0143] Among them, △ρ2 is the relative change in the second density, g / cm 3 ;

[0144] ρ 全 represents the second density obtained after correction of the entire well section, g / cm 3 ;

[0145] DEN2 取芯 is the density value of the sandstone core, g / cm 3 .

[0146] 210. Use the large-scale median filtering method to filter the porosity curve of this sandstone section.

[0147] Similarly, use the large-scale filtering method to filter the porosity curve of the sandstone section to obtain the filtered porosity curve β1.

[0148] 211. Fit based on the filtered porosity curve of this sandstone section and this relative change in the second density to obtain the relational expression of the change in the second density.

[0149] Among them, the first density change relationship can be expressed by the following relationship 9.

[0150] △ρ2 = F * β1 + G Relationship 9

[0151] Among them, △ρ2 is the relative change in the first density, g / cm 3 ;

[0152] β1 is the porosity after filtering in the sandstone section, dimensionless;

[0153] F and G are coefficients to be obtained, dimensionless.

[0154] 212. Based on the second density change relationship, the density curve of the sandstone section is corrected to obtain the corrected third density curve.

[0155] Among them, the third density curve is also the result of density curve trend correction mainly for the sandstone section, and the expression of the third density curve can be expressed by the following relationship 10.

[0156] ρ 砂 = ρ 全 -(F * β1 + G) Relationship 10

[0157] Among them, ρ 砂 represents the third density obtained after correcting the sandstone section, g / cm 3 ;

[0158] ρ 全 represents the second density obtained after correcting the entire well section, g / cm 3 ;

[0159] β1 is the porosity after filtering in the sandstone section, dimensionless;

[0160] F and G are coefficients to be obtained, dimensionless.

[0161] 213. Combine the second density curve and the third density curve to obtain the fourth density curve, where the mudstone section corresponds to the second density curve and the sandstone section corresponds to the third density curve.

[0162] When applying this embodiment to an electronic device, the lithology curve can be distinguished based on the markings made in the programming language in step 202 above, so as to more clearly distinguish mudstone and sandstone. In the programming language,

[0163] Apply conditional statements to achieve the overall correction of sandstone and mudstone and obtain the finally corrected data volume.

[0164] If lithology = 1

[0165] DEN 校正 = ρ 全

[0166] Else lithology = 2

[0167] DEN 校正 = ρ 砂

[0168] Verify the rationality of the fourth density curve based on well logging data and seismic data.

[0169] In this step, check the rationality of the corrected curve according to the relative relationship determined by well logging and seismic data and the understanding of seismic data to ensure accurate results.

[0170] Please refer to Figure 4 , Figure 4 is a synthetic record calibration comparison chart of a wellbore diameter collapse before, multiple regression fitting, and the well logging environment correction method provided by the embodiments of the present application. Figure 4 respectively shows the wellbore diameter, original density, expanded diameter rate density, original acoustic wave, expanded diameter rate acoustic wave, lithology, stratification, original synthetic record, synthetic record of the conventional method, synthetic record of the improved method provided by the present embodiment, FD5 three-dimensional Jurassic data, and time-depth. Among them, the layer numbers corresponding to the stratification column are, from top to bottom: k1tg, j3q3, j3q2, j3q, j2t3, j2t2, j2t1; the correlation corresponding to the original synthetic record is 0.48, the correlation corresponding to the synthetic record of the conventional method is 0.51, and the correlation corresponding to the synthetic record of the improved method provided by the present embodiment is 0.80; the left numbers corresponding to time-depth are time, from top to bottom: 2800ms, 2900ms, 3000ms, 3100ms, and the right numbers corresponding to time-depth are depth, from top to bottom: 1800m, 2000m, 2200m, 2400m, 2600m. Based on Figure 4 , first, a comparative analysis is carried out before and after the correction in the shale section. Before correction, the density curve in the collapsed section is negatively correlated with the wellbore diameter collapse rate, which does not conform to the actual geological situation; after correction, there is a linear relationship between the collapse amplitude and the corrected density, eliminating the influence of the collapsed wellbore diameter on the shale density. Similarly, a comparative analysis is also carried out before and after the correction in the sandstone section. Before correction, the relationship between the sandstone density and porosity is chaotic, which violates the basic principles of rock physics; after correction, the sandstone density curve is negatively correlated with the effective porosity, which conforms to the general geological law.

[0171] All of the above optional technical solutions can be combined arbitrarily to form optional embodiments of the present application, which will not be elaborated here one by one.

[0172] The technical solution provided by the embodiments of this application distinguishes shale sections and sandstone sections based on the depth curve of well logging and the corresponding first spontaneous potential curve; based on the caliper curve of the collapsed section in the shale section, the first density change relationship is obtained to correct the density curve of the entire well section; on the basis of the above correction, based on the porosity curve of the sandstone section, the second density change relationship is obtained to correct the density curve of the sandstone section; by combining the curves corrected twice, the overall correction of the entire well section and the key correction of the sandstone section are realized. This technical solution is based on the dual-trend control of calculating the caliper collapse rate and porosity, and superimposes the relative density change details, realizing the accurate correction of the density curves of sandstone and shale in the case of poor quality of conventional well logging curves, large-area caliper collapse, no standard layer, and standard curves, thereby effectively improving the quality of well logging data.

[0173] After correction based on the above method, the influence of the caliper on the density curve is eliminated, and a positive correlation between the sandstone porosity and density is established; the background trend of the density curve is changed, but the details of the density amplitude change are retained, which is more in line with the geological law.

[0174] Figure 5 It is a schematic structural diagram of a device for well logging environment correction provided by the embodiments of this application. Please refer to Figure 5 This device includes:

[0175] The data acquisition module 501 is used to acquire the depth curve of well logging and the corresponding first spontaneous potential curve;

[0176] The data processing module 502 is used to correct the first spontaneous potential curve based on the depth curve to obtain the corrected second spontaneous potential curve. The second spontaneous potential curve between the minimum value and the maximum value of the first spontaneous potential curve corresponds to the shale section, and other second spontaneous potential curves correspond to the sandstone section;

[0177] The entire well section module 503 is used to obtain the first density change relationship based on the caliper curve of the collapsed section, the first density curve, and the measured density value of the shale core;

[0178] The entire well section module 503 is also used to correct the density curve of the entire well section based on the first density change relationship to obtain the corrected second density curve;

[0179] The sandstone module 504 is used to calculate the porosity curve of the sandstone section based on the total nuclear magnetic porosity and the porosity of the effective shale section;

[0180] The sandstone module 504 is also used to calculate the relative second density change of the collapsed section based on the second density curve and the measured density value of the sandstone core;

[0181] The sandstone module 504 is also used to perform fitting based on the porosity curve of the sandstone section and the relative change amount of the second density to obtain a second density change amount relationship formula;

[0182] The sandstone module 504 is also used to correct the density curve of the sandstone section based on the second density change amount relationship formula to obtain a corrected third density curve;

[0183] The combination module 505 is used to combine the second density curve and the third density curve to obtain a fourth density curve, where the shale section corresponds to the second density curve and the sandstone section corresponds to the third density curve.

[0184] In a possible implementation manner, the full well section module 503 is used for:

[0185] Calculating the hole enlargement rate of the shale section based on the hole diameter curve of the caving section;

[0186] Calculating the relative change amount of the first density of the caving section based on the first density curve of the caving section and the measured density value of the shale core;

[0187] Performing fitting based on the hole enlargement rate and the relative change amount of the first density to obtain a first density change amount relationship formula.

[0188] The technical solution provided by the embodiment of the present application distinguishes the shale section and the sandstone section according to the depth curve of the well logging and the corresponding first spontaneous potential curve; based on the hole diameter curve of the caving section of the shale section, a first density change amount relationship formula is obtained to correct the density curve of the full well section; on the basis of the above correction, based on the porosity curve of the sandstone section, a second density change amount relationship formula is obtained to correct the density curve of the sandstone section; by combining the curves corrected twice, the overall correction of the full well section and the key correction of the sandstone section are realized. This technical solution is based on the double trend control of calculating the hole diameter caving rate and porosity, and superimposes the relative change details of the density, realizing accurate correction of the density curves of sandstone and shale in the case of poor quality of conventional well logging curves, large-area hole diameter caving, no standard layer, and standard curves, thereby effectively improving the quality of well logging data.

[0189] It should be noted that: when the well logging environment correction device provided in the above embodiment performs well logging environment correction, only the above-mentioned division of each functional module is used for illustration. In actual application, the above functions can be allocated to different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the well logging environment correction device provided in the above embodiment and the method embodiment of well logging environment correction belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be elaborated here.

[0190] Figure 6It is a schematic structural diagram of an electronic device provided by an embodiment of the present application. The electronic device 60 may vary greatly due to different configurations or performances, and may include one or more central processing units (CPUs) 61 and one or more memories 62. Among them, at least one program code is stored in the memory 62, and the at least one program code is loaded and executed by the processor 61 to implement the methods provided in the above-mentioned method embodiments. Of course, the electronic device may also have components such as wired or wireless network interfaces, keyboards, and input / output interfaces for input / output. The electronic device may also include other components for implementing device functions, which will not be elaborated here.

[0191] In some embodiments, the computer program involved in the embodiments of the present application may be deployed to be executed on an electronic device, or on multiple electronic devices located at one location, or on multiple electronic devices distributed at multiple locations and interconnected through a communication network. The multiple electronic devices distributed at multiple locations and interconnected through a communication network may form a blockchain system.

[0192] In an exemplary embodiment, a computer-readable storage medium is also provided, such as a memory including program code. The above program code can be executed by a processor in an electronic device to complete the method for well logging environment correction in the above embodiments. For example, the computer-readable storage medium may be a Read-Only Memory (ROM), a Random Access Memory (RAM), a Compact Disc Read-Only Memory (CD-ROM), magnetic tape, floppy disk, and optical data storage device, etc.

[0193] Those of ordinary skill in the art can understand that all or part of the steps for implementing the above embodiments can be completed by hardware, or can be completed by a program instructing relevant hardware. The above program can be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk, or an optical disc, etc.

[0194] In an exemplary embodiment, a computer program product is also provided, including computer instructions, and when the computer instructions are executed by a processor, the method for well logging environment correction provided in any of the above possible implementation manners is implemented.

[0195] The above are only optional embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for well logging environment correction, characterized in that, The method includes: Obtaining the depth curve of well logging and the corresponding first spontaneous potential curve; Based on the depth curve, correcting the first spontaneous potential curve to obtain the corrected second spontaneous potential curve. The second spontaneous potential curve between the minimum value and the maximum value of the first spontaneous potential curve corresponds to the shale section, and other second spontaneous potential curves correspond to the sandstone section; Based on the borehole diameter curve in the collapse section, the first density curve, and the measured density value of shale core sampling, obtaining the first density change amount relationship; Based on the first density change amount relationship, correcting the density curve of the entire well section to obtain the corrected second density curve; Based on the nuclear magnetic total porosity and the porosity of the effective shale section, calculating the porosity curve of the sandstone section; Based on the second density curve and the measured density value of sandstone core sampling, calculating the relative change amount of the second density in the collapse section; Based on the porosity curve of the sandstone section and the relative change amount of the second density, performing fitting to obtain the second density change amount relationship; Based on the second density change amount relationship, correcting the density curve of the sandstone section to obtain the corrected third density curve; Combining the second density curve and the third density curve to obtain the fourth density curve, where the shale section corresponds to the second density curve and the sandstone section corresponds to the third density curve.

2. The method according to claim 1, characterized in that The obtaining the first density change amount relationship based on the borehole diameter curve in the collapse section, the first density curve, and the measured density value of shale core sampling includes: Based on the borehole diameter curve in the collapse section, calculating the diameter expansion rate of the shale section; Based on the first density curve in the collapse section and the measured density value of shale core sampling, calculating the relative change amount of the first density in the collapse section; Based on the diameter expansion rate and the relative change amount of the first density, performing fitting to obtain the first density change amount relationship.

3. The method according to claim 2, characterized in that, The method further includes: Using the large-scale median filtering method to filter the diameter expansion rate and the relative change amount of the first density.

4. The method according to claim 1, characterized in that, The method further includes: Using the large-scale median filtering method to filter the porosity curve of the sandstone section.

5. The method according to claim 1, characterized in that The method further includes: Based on well logging data and seismic data, verifying the rationality of the fourth density curve.

6. A device for well logging environment correction, characterized in that, The device includes: A data acquisition module, configured to obtain the depth curve of well logging and the corresponding first spontaneous potential curve; A data processing module, configured to correct the first spontaneous potential curve based on the depth curve to obtain the corrected second spontaneous potential curve. The second spontaneous potential curve between the minimum value and the maximum value of the first spontaneous potential curve corresponds to the shale section, and other second spontaneous potential curves correspond to the sandstone section; An entire well section module, configured to obtain the first density change amount relationship based on the borehole diameter curve in the collapse section, the first density curve, and the measured density value of shale core sampling; The entire well section module is further configured to correct the density curve of the entire well section based on the first density change amount relationship to obtain the corrected second density curve; A sandstone module, configured to calculate the porosity curve of the sandstone section based on the nuclear magnetic total porosity and the porosity of the effective shale section; The sandstone module is also used to calculate the relative change in the second density of the collapsed section based on the second density curve and the measured density value of the sandstone core sample. The sandstone module is also used to perform fitting based on the porosity curve of the sandstone section and the relative change in the second density to obtain a relationship for the change in the second density. The sandstone module is also used to correct the density curve of the sandstone section based on the relationship for the change in the second density to obtain a corrected third density curve. The combining module is used to combine the second density curve and the third density curve to obtain a fourth density curve, where the shale section corresponds to the second density curve and the sandstone section corresponds to the third density curve.

7. The device according to claim 6, characterized in that, The full well section module is used to: Calculate the hole enlargement rate of the shale section based on the hole diameter curve of the collapsed section. Calculate the relative change in the first density of the collapsed section based on the first density curve of the collapsed section and the measured density value of the shale core sample. Perform fitting based on the hole enlargement rate and the relative change in the first density to obtain a relationship for the change in the first density.

8. An electronic device, characterized in that, Comprising: One or more processors; One or more memories for storing instructions executable by the one or more processors; Wherein, the one or more processors are configured to execute the instructions to implement the well logging environment correction method according to any one of claims 1 to 5.

9. A storage medium, characterized in that, When the instructions in the storage medium are executed by the processor of the electronic device, the electronic device is enabled to execute the well logging environment correction method according to any one of claims 1 to 5.

10. A computer program product, comprising computer instructions, characterized in that, The computer instructions, when executed by the processor, implement the well logging environment correction method according to any one of claims 1 to 5.

Images