Deposition unconformity high-precision identification method, device and equipment based on double standard layers and medium

Abstract

The invention belongs to the technical field of geophysical prospecting engineering, and particularly discloses a deposition unconformity high-precision identification method, device and equipment based on double standard layers and a medium. The method comprises the following steps: firstly, on the basis of well connection comparative analysis of a drilled area, finely synthesizing seismic record calibration, and establishing a corresponding relation between depth domain stratigraphic geologic features and time domain seismic response; thirdly, identifying and tracking the unconformity surface through a double-standard layer-by-layer leveling unconformity identification method, then optimizing an unconformity horizon result by applying a weighted average optimization method to form a final unconformity interpretation horizon, and finally further checking and optimizing to compile an unconformity structure map. According to the method, the phenomena of unconformity upper and lower strata seismic homonymous axis homonymous direction, sharp angle bending, strata thickness trend abnormity and the like caused by inaccurate unconformity identification can be eliminated, the unconformity identification precision is improved, and the method is suitable for research on basin oil and gas reservoir rules in geophysical exploration.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of geophysical prospecting engineering, and particularly relates to a high-precision identification method, device, equipment and medium for sedimentary unconformity based on double standard layers. BACKGROUND

[0002] Unconformity refers to a surface where a deposition area is subjected to regional uplift, deposition is interrupted and denudation occurs, and then deposition occurs again in a later period. Research shows that unconformity plays an important role in the formation of some large gas fields: first, weathering crust karst action improves the porosity and permeability conditions of reservoirs below the unconformity surface, forming large-scale karst reservoirs; second, the vicinity of the unconformity surface is conducive to forming a good source-reservoir-cap combination, providing a basis for the formation of large gas fields; third, the unconformity produces stratigraphic pinch-out and uneven ancient landforms, forming large-area stratigraphic traps and lithologic trap groups; fourth, the unconformity provides an advantageous channel for lateral migration of oil and gas; and fifth, the unconformity is conducive to the large-scale accumulation of oil and gas. Therefore, the study of unconformity plays a very important role in the study of basin evolution and oil and gas reservoir regularity.

[0003] At present, the commonly used unconformity identification method for seismic data interpretation is to track the seismic homodromous axis through automatic, manual or man-machine interactive technical methods at a determined time or depth position based on well-to-seismic calibration, so as to realize the identification and interpretation of the unconformity. After the skeleton grid survey line tracking is completed, the horizon is finally interpreted into 1x1 grid through horizon interpolation method.

[0004] However, due to the large difference in lithology and lithofacies between the upper and lower strata of the unconformity, there are often ancient erosion surfaces between the two sets of strata, accompanied by ancient weathering crust, residual deposits or basal conglomerate; on the seismic profile, the main performance is the discontinuity of the homodromous axis, the complex wave form, thereby causing inaccurate tracking of the unconformity surface or insufficient tracking precision. Along the unconformity surface, the seismic data are subjected to horizon flattening display, and the upper and lower strata will simultaneously appear the same direction of the seismic homodromous axis, sharp angle bending, and even the phenomenon of sudden change in the thickness trend. These are the inevitable problems of inaccurate unconformity identification by conventional unconformity identification technical methods.

[0005] A Chinese invention patent application with the application publication number CN105607129A discloses a seismic identification method for complex fault block unconformity surface, which improves the matching correlation degree of the synthetic seismic record and the well seismic by reconstructing the sound wave curve, thereby improving the calibration precision of the seismic response characteristics of the unconformity surface in the complex structure area, and then combining the well-to-seismic profile characteristics of the simple structure area and the complex area to finally interpret the unconformity surface. Although this method can improve the interpretation precision of the unconformity of the strata near the well in the complex structure area, it has no obvious effect on the interpretation precision of the unconformity surface between the wells, and essentially still belongs to the regional unconformity surface stratum interpretation by applying the traditional interpretation method. SUMMARY

[0006] The present application aims to provide a high-precision identification method for depositional unconformity based on double standard layers to improve the identification precision of the unconformity.

[0007] The second object of the present application is to provide a high-precision identification device for depositional unconformity based on double standard layers for implementing the above-mentioned high-precision identification method for depositional unconformity based on double standard layers.

[0008] The third object of the present application is to provide a terminal device capable of implementing the above-mentioned high-precision identification method for depositional unconformity based on double standard layers when executing its own program.

[0009] The fourth object of the present application is to provide a computer-readable storage medium for storing the above-mentioned high-precision identification method for depositional unconformity based on double standard layers.

[0010] To achieve the above objects, the present application employs the following technical solutions:

[0011] A high-precision identification method for depositional unconformity based on double standard layers is performed in the following order of steps:

[0012] S1, layering is integrated based on well logging data, drilling data and well geology;

[0013] S2, on the basis of the layering, regional well correlation is performed on the drilled well data to analyze the distribution characteristics of the strata of each era in the horizontal direction and determine the missing strata and unconformity regions;

[0014] S3, on the basis of the clear geological layering and unconformity strata, synthetic seismogram is made by integrating acoustic travel time logging data and seismic data, fine calibration of the synthetic seismogram and well seismic record is completed, the depth-time correspondence between the geological layering and the seismic response position is established, and the unconformity seismic response characteristics are determined;

[0015] S4, standard layers are selected in the upper and lower strata of the unconformity to obtain upper and lower standard layers;

[0016] S5, the seismic events of the unconformity surface are tracked and interpreted with the upper standard layer as the reference and the lower standard layer as the reference;

[0017] S6, the unconformity positions tracked by the two sets of different standard layers are optimized by weighted average method to form the final unconformity position;

[0018] S7, on the basis of step S6, using unconformity horizon to carry out seismic data layer flattening, checking whether the upper and lower strata at the non-fault position have local same direction bending or thickness abnormal phenomenon, if not, directly executing step S8; if yes, returning to step S6 to modify the weighting coefficient and then re-executing from step S6, if still having problem, returning to S5 to check and modify the local interpretation result, interactive optimization until the unconformity horizon is correct, then executing step S8;

[0019] S8, carrying out layer interpolation on the unconformity horizon interpretation result, finally completing the seismic survey network density grid, and preparing unconformity interpretation horizon time structure map and depth structure map.

[0020] As a limitation, in step S5, in the tracking interpretation process, taking the thickness trend of the unconformity surface to the standard layer as a reference, the unconformity seismic same direction axis is tracked and interpreted; for the region with strong seismic reflection amplitude energy and lateral continuity, the automatic tracking method is adopted; for the region with weak seismic reflection amplitude energy and lateral discontinuity, the man-machine interaction or manual tracking method is adopted.

[0021] As a second limitation, in step S6, the weighted average method is expressed as

[0022] H P =(k1*H1+k2*H2) / (k1+k2)

[0023] In the formula, H P is the final unconformity horizon; H1 is the unconformity horizon result identified by referring to the upper standard layer; H2 is the unconformity result identified by referring to the lower standard layer; K1 is the weighting coefficient of H1 layer; K2 is the weighting coefficient of H2 layer, K1=70, K2=30.

[0024] A kind of high-precision recognition device of sedimentary unconformity based on double standard layer, for implementing the high-precision recognition method of sedimentary unconformity based on double standard layer described above, the device includes: geological layer module, comparison analysis module, well seismic calibration module, standard layer selection module, tracking interpretation module, optimization processing module, layer flattening checking module, structure map preparation module;

[0025] Geological layer module, well geological layering is carried out by comprehensively logging data, logging data and drilling data, and the result is output to comparison analysis module;

[0026] Comparison analysis module, on the basis of layering, the missing stratum and unconformity region are determined by carrying out regional well correlation on drilled well data, analyzing the lateral distribution characteristics of stratum in each era, and the result is output to well seismic calibration module;

[0027] The well-seismic calibration module, on the basis of clear geological layering and unconformable strata, synthesizes acoustic traveltime logging data and seismic data to produce artificial synthetic seismic records, completes fine calibration of the synthetic seismic records and well-side seismic record traces, establishes a deep-time correspondence between the geological layering and seismic response positions, clearly defines unconformable seismic response characteristics, and outputs the results to the standard layer selection module;

[0028] The standard layer selection module selects standard layers in the upper and lower unconformable strata to obtain an upper standard layer and a lower standard layer, and outputs the results to the tracking interpretation module;

[0029] The tracking interpretation module performs tracking interpretation on the unconformable surface seismic homodromous axes with the upper standard layer as the reference and the lower standard layer as the reference, respectively, and outputs the results to the optimization processing module;

[0030] The optimization processing module optimizes the unconformable layer positions tracked by referring to two different standard layers by using a weighted average method to form the final unconformable layer positions, and outputs the results to the layer flattening checking module;

[0031] The layer flattening checking module performs seismic data layer flattening on the final unconformable layer positions using the unconformable layer positions, checks whether the upper and lower strata at non-fault positions simultaneously have local homodromous bending or thickness abnormality, and if not, outputs the results to the structural map compilation module; if so, outputs the results to the optimization processing module or the tracking interpretation module for interactive optimization until the unconformable layer positions are correct, and then outputs the results to the structural map compilation module;

[0032] The structural map compilation module performs layer interpolation on the unconformable layer interpretation results to finally complete a seismic survey network density grid and compile an unconformable interpretation layer position time structural map and a depth structural map.

[0033] A terminal device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the above-mentioned method for high-precision identification of depositional unconformity based on double standard layers when executing the computer program.

[0034] A computer-readable storage medium stores a computer program, and the computer program is executed by a processor to implement the above-mentioned method for high-precision identification of depositional unconformity based on double standard layers.

[0035] Compared with the prior art, the technical progress achieved by the above technical solution is that:

[0036] (1) This invention uses standard layers as a reference to flatten the seismic data volume, thereby highlighting the lateral contrast features and trends of the unconformity. At the same time, referencing the upper and lower standard layers can eliminate the identification error caused by sedimentary differences, thus making the unconformity identification more accurate and reasonable. Finally, the weighted average optimization method can further reduce the error, optimize the identification results, and improve the identification accuracy of the unconformity.

[0037] (2) By adopting the unconformity interpretation results identified in this invention, phenomena such as seismic co-directional axis, sharp-angle bending, and abnormal stratigraphic thickness trend caused by inaccurate unconformity identification are eliminated, thereby improving the accuracy of unconformity identification and providing more accurate analytical data for the study of regional and even basin oil and gas reservoir patterns.

[0038] This invention belongs to the field of geophysical engineering technology and can improve the accuracy of unconformity identification. Attached Figure Description

[0039] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0040] In the attached diagram:

[0041] Figure 1 This is a flowchart of the method in Embodiment 1 of the present invention;

[0042] Figure 2 This is a cross-sectional view of the upper standard layer flattening and identification of non-conformity in Embodiment 1 of the present invention;

[0043] Figure 3 This is a cross-sectional view of the lower standard layer flattening and identification of non-conformity in Embodiment 1 of the present invention;

[0044] Figure 4 This invention employs conventional techniques to identify flattened cross-sectional views of unconformity layers.

[0045] Figure 5 A flattened cross-sectional view is used to identify the unconformity layer using the method of Embodiment 1 of the present invention. Detailed Implementation

[0046] The preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0047] Example 1: A high-precision identification method for depositional unconformities based on dual standard layers

[0048] like Figure 1 As shown, this embodiment is performed in the following order:

[0049] S1. By integrating well logging data, well logging data and drilling data, the geological stratification of the well is unified to ensure that the geological stratification characteristics are consistent, accurate and reasonable.

[0050] S2. Based on the stratigraphic sequence, conduct regional well-to-well comparisons of drilled data, analyze the lateral distribution characteristics of strata of different ages, and identify missing strata and unconformities.

[0051] S3. Based on the overall strata, clarify the geological strata; based on the identification of missing strata and unconformity areas, clarify the unconformity strata; based on the clarified geological strata and unconformity strata, synthesize artificial seismic records by integrating sonic transit time logging data and seismic data, complete the fine-grained stratigraphic calibration, establish the deep-time correspondence between geological strata and seismic response locations, and clarify the seismic response characteristics of unconformity.

[0052] S4. Select standard layers from the unconformable upper and lower strata to obtain the upper and lower standard layers;

[0053] S5. Using the flattening of the above standard layers as a reference and the flattening of the lower standard layers as a reference, the seismic co-directional axis of the unconformity surface is traced and interpreted respectively.

[0054] S6. The unintegrated layers traced by two different standard layers are optimized by weighted average method to form the final unintegrated layers.

[0055] S7. Based on step S6, flatten the seismic data layers using unconformity horizons and check whether the strata above and below the non-fault location simultaneously exhibit local bending or thickness anomalies. If not, proceed directly to step S8; if so, perform iterative interpretation and interactive optimization until the unconformity horizon is correct, and then proceed to step S8.

[0056] S8. Perform intra-layer interpolation on the unconformity interpretation results to finally complete the seismic network density grid, and compile the unconformity interpretation layer time structure map and depth structure map. In this embodiment, a 1×1 seismic network density grid is finally completed.

[0057] In step S7, the iterative interpretation process is as follows: first, return to step S6 to modify the weighting coefficients and then start execution again from step S6. If there are still problems, return to S5 to check and modify the local interpretation results and then start execution again from step S6. If there are still problems, return to S5 again to check and modify the local interpretation results and then start execution again from step S6.

[0058] In step S4, the conditions for selecting the standard layer are: ① Stable development throughout the area, with obvious lithological, electrical, or paleontological characteristics; ② Close to the unconformity, within 200 ms; ③ Obvious seismic response characteristics, with obvious peaks or troughs, small lateral variation in waveform reflection amplitude intensity, easy to identify and track; ④ When the standard layer is leveled, the upper and lower strata, except at fault locations, do not show the same direction, sharp angle bending, or abnormal thickness trend of the seismic axis.

[0059] As an optimization of this embodiment, in step S5, during the tracking and interpretation process, the thickness trend from the unconformity surface to the standard layer is used as a reference to track and interpret the unconformity seismic axis in the same direction; an automatic tracking method is used for areas with strong seismic reflection amplitude energy and lateral continuity; and a human-computer interaction or manual method is used for tracking areas with weak seismic reflection amplitude energy and lateral discontinuity. In this step, the seismic data volume is flattened and displayed based on the tracking and interpretation results of the upper standard layer, such as... Figure 2 The image shown is a cross-sectional view of the unconformity identified by flattening the upper standard layers, as follows: Figure 3 The image shown is a profile of unconformities identified by flattening the standard layers. The seismic network density in the upper / lower standard layer tracking interpretation results is 4×4.

[0060] Furthermore, in step S6, the weighted average method formula is expressed as follows:

[0061] H P = (k1*H1+k2*H2) / (k1+k2)

[0062] In the formula, H P H1 represents the final unintegrated layer; H2 represents the unintegrated layer identified with reference to the upper standard layer; K1 represents the unintegrated layer identified with reference to the lower standard layer; K2 represents the weighting coefficient of layer H1; K1 = 70, K2 = 30.

[0063] like Figure 4 The image shown is a flattened cross-section of the unconformity layer identified using conventional techniques. Figure 5 To identify unconformity layer flattened profiles using the method of this embodiment, a comparison shows that after applying the method provided in this embodiment, abnormal sites such as seismic axes in the same direction, sharp-angle bending, and sudden thickening of seismic thickness trends are significantly eliminated. The interpretation of unconformity surfaces is more reasonable and more accurate. Compared with conventional methods, the interpretation accuracy of unconformity surfaces is improved by about 20%.

[0064] Example 2: A high-precision identification device for depositional unconformities based on dual standard layers

[0065] This embodiment is used to implement Embodiment 1. This embodiment includes: geological strata module, comparative analysis module, well-seismic calibration module, standard layer selection module, tracing interpretation module, optimization processing module, layer flattening inspection module, and structural map compilation module;

[0066] The geological stratification module integrates well logging data, well logging data, and drilling data to stratify the geological layers of the well and outputs the results to the comparative analysis module.

[0067] The comparative analysis module, based on the strata, performs regional well-to-well comparisons on the drilled data, analyzes the lateral distribution characteristics of strata of different ages, identifies missing strata and unconformities, and outputs the results to the well-seismic calibration module.

[0068] The well-seismic calibration module, based on clearly defined geological strata and unconformities, synthesizes artificial seismic records by integrating sonic transit time logging data and seismic data. It completes the fine calibration of the synthetic seismic records and the seismic record traces near the well, establishes the deep-time correspondence between geological strata and seismic response locations, clarifies the seismic response characteristics of unconformities, and outputs the results to the standard layer selection module. The standard layer selection module selects standard layers from the upper and lower strata of the unconformities to obtain the upper and lower standard layers, and outputs the results to the tracking and interpretation module.

[0069] The tracking and interpretation module uses the flattening of the upper standard layer and the flattening of the lower standard layer as references to track and interpret the seismic co-directional axis of the unconformity surface, and outputs the results to the optimization processing module.

[0070] The optimization processing module will use a weighted average method to optimize the unintegrated layers by referring to two different sets of standard layer tracking, forming the final unintegrated layers, and output the results to the layer flattening check module.

[0071] The layer flattening check module uses the unconformity layer to flatten the seismic data layers, checking whether the strata above and below the non-fault location have local bending or thickness anomalies in the same direction at the same time. If not, the result is output to the structural map compilation module; if so, the result is output to the optimization processing module, and interactive optimization is performed until the unconformity layer is correct before the result is output to the structural map compilation module.

[0072] The structural map compilation module performs intra-layer interpolation on the unconformity layer interpretation results, and finally completes the seismic network density 1×1 grid, compiling the unconformity interpretation layer time structural map and depth structural map.

[0073] Example 3: A terminal device

[0074] This embodiment includes 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 method in embodiment 1.

[0075] Example 4: A computer-readable storage medium

[0076] The computer-readable storage medium provided in this embodiment stores a computer program, which, when executed by a processor, is used to implement the method in Embodiment 1.

[0077] The computer-readable storage medium can be a computer storage medium or a communication medium. A communication medium includes any medium that facilitates the transfer of computer programs from one location to another. A computer storage medium can be any available medium accessible to a general-purpose or special-purpose computer. For example, a computer-readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the computer-readable storage medium. Of course, the computer-readable storage medium can also be a component of the processor. The processor and the computer-readable storage medium can reside in an application-specific integrated circuit (ASIC). Alternatively, the ASIC can reside in a user equipment. Of course, the processor and the computer-readable storage medium can also exist as discrete components in a communication device. Specifically, the computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk, etc. The storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

Claims

1. A high-precision identification method for a double-standard-layer-based deposition unconformity, characterized in that, The following steps are performed in sequence: S1, comprehensive well logging data, well logging data and drilling data are used to divide the well geology into layers; S2, on the basis of the layering, the drilled well data is compared and analyzed, the distribution characteristics of the strata of each era in the horizontal direction are analyzed, and the missing strata and unconformity regions are determined; S3, on the basis of clear geological layering and unconformable strata, synthetic seismogram is made by comprehensively using acoustic travel time logging data and seismic data, fine calibration of synthetic seismogram and well seismic record is completed, the depth-time correspondence between geological layering and seismic response position is established, and the unconformity seismic response characteristics are determined; S4, a standard layer is selected in the upper and lower strata of the unconformity, and an upper standard layer and a lower standard layer are obtained; S5, the unconformity seismic events are tracked and interpreted with the upper standard layer as reference and the lower standard layer as reference; S6, the unconformity layer positions tracked by referring to the two different standard layers are optimized by weighted average method, and the final unconformity layer position is formed; S7, on the basis of step S6, the unconformity layer position is used for seismic data layer flattening, and it is checked whether the upper and lower strata at the non-fault position have local same direction bending or thickness abnormal phenomenon, if not, step S8 is directly executed, if yes, the weighted coefficient is modified and the step S6 is re-executed, if there is still a problem, the local interpretation result is checked and modified, and the interactive optimization is performed until the unconformity layer position is correct, and then step S8 is executed; S8, the unconformity layer position interpretation result is interpolated, and finally the seismic survey network density grid is completed, and the unconformity interpretation layer position time structure map and depth structure map are prepared.

2. The method according to claim 1, wherein, In step S5, the unconformity seismic events are tracked and interpreted with the thickness trend of the unconformity surface to the standard layer as reference; For the region with strong seismic reflection amplitude energy and horizontal continuity, an automatic tracking method is adopted; For the region with weak seismic reflection amplitude energy and horizontal discontinuity, a man-machine interaction or manual tracking method is adopted.

3. The method according to claim 1, wherein, In step S6, the weighted average method is expressed as H P = (k1*H1 + k2*H2) / (k1 + k2) In the formula, H P is a non- matching final horizon; H1 is the unconformity layer position result identified by referring to the upper standard layer; H2 is the unconformity result identified by referring to the lower standard layer; K1 is the weighted coefficient of H1 layer; K2 is the weighted coefficient of H2 layer, K1=70, K2=30.

4. A device for high-precision identification of a double-standard-layer-based depositional unconformity, used for implementing the high-precision identification method of the double-standard-layer-based depositional unconformity according to any one of claims 1 to 3, characterized in that, The device comprises a geological layering module, a comparison and analysis module, a well-seismic calibration module, a standard layer selection module, a tracking interpretation module, an optimization processing module, a layer flattening checking module, and a structure map preparation module; The geological layering module divides the well geology into layers by comprehensively using well logging data, well logging data and drilling data, and outputs the result to the comparison and analysis module; The comparison and analysis module compares and analyzes the drilled well data on the basis of the layering, analyzes the distribution characteristics of the strata of each era in the horizontal direction, determines the missing strata and unconformity regions, and outputs the result to the well-seismic calibration module; The well-seismic calibration module, on the basis of clear geological layering and unconformable strata, synthesizes the acoustic traveltime logging data and seismic data to produce artificial synthetic seismic records, completes fine calibration of the synthetic seismic records and well-side seismic record traces, establishes the deep-time corresponding relationship between the geological layering and seismic response positions, clearly defines the unconformable seismic response characteristics, and outputs the results to the standard layer selection module; The standard layer selection module selects standard layers in the upper and lower unconformable strata to obtain the upper and lower standard layers, and outputs the results to the tracking interpretation module; The tracking interpretation module performs tracking interpretation on the unconformable surface seismic homodromous axis with the upper standard layer as the reference and the lower standard layer as the reference, respectively, and outputs the results to the optimization processing module; The optimization processing module performs weighted average optimization on the unconformable layer positions tracked by reference to the two different standard layers, forms the final unconformable layer position, and outputs the results to the layer flattening checking module; The layer flattening checking module performs seismic data layer flattening on the unconformable final layer position with the unconformable layer position, checks whether the upper and lower strata on the non-fault position have local homodromous bending or thickness abnormality phenomenon at the same time, and if not, outputs the results to the structure map compilation module; if so, outputs the results to the optimization processing module or the tracking interpretation module for interactive optimization until the unconformable layer position is correct, and then outputs the results to the structure map compilation module; The structure map compilation module performs layer interpolation of the unconformable layer interpretation results to finally complete the seismic survey network density grid, and compiles the unconformable interpretation layer position time structure map and depth structure map.

5. A terminal device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes the computer program to realize the method for high-precision identification of depositional unconformity based on double standard layers according to any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is executed by the processor to realize the method for high-precision identification of depositional unconformity based on double standard layers according to any one of claims 1 to 3.

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