Time-depth conversion method and device for eliminating speed anomaly influence, and storage medium

Abstract

The invention discloses a time-depth conversion method and device for eliminating speed anomaly influence, and a storage medium. The method comprises the following steps: obtaining a seabed depth structure based on a seabed time structure in combination with seawater sound wave speed treatment; performing linear fitting on the basis of the time thickness and the depth thickness of the drilling data to obtain a linear relationship between the first time thickness and the first depth thickness from the seabed to the limestone top; based on the first time thickness, the depth and thickness from the seabed to the limestone top are obtained through the linear relation; a limestone top depth structure is constructed based on the seabed depth structure and the depth and thickness from the seabed to the limestone top; and obtaining a second depth thickness from the target layer to the limestone top based on the limestone top time structure and the target layer time structure in combination with layer velocity processing, and obtaining a target layer depth structure based on the limestone top depth structure and the second depth thickness. The method can realize time-depth conversion for eliminating the influence of low-speed abnormity of seawater and high-speed abnormity of limestone, and can be widely applied to the technical field of depth structure solving.

Description

Technical Field

[0001] The present invention relates to the technical field of deep structure calculation, and particularly to a time-depth conversion method, device, and storage medium for eliminating the influence of velocity anomalies. Background Art

[0002] The depth structure map generated by the conventional time-depth conversion technology from the time contour map interpreted from the seismic time migration profile often has a certain degree of structural distortion. There are many factors affecting the structure, but the mechanism causing the structural distortion ultimately lies in the lateral variation of velocity. Both low-velocity anomaly bodies and high-velocity anomaly bodies can cause structural distortion. The change in seabed topography, especially the seawater filled in trenches and troughs, is actually equivalent to a low-velocity lithological body. When seismic waves pass through a low-velocity lithological body, the time required is more than that required to pass through the surrounding rock of the same thickness, thus causing a downward pull distortion of the strata. According to the principle of seismic wave propagation, reef limestone will inevitably cause an upward pull distortion of the strata due to its higher velocity than the surrounding rock. How to simultaneously eliminate the influence of the low-velocity anomaly body of seawater and the high-velocity anomaly body of reef limestone on the structure is the key to time-depth conversion structure mapping.

[0003] However, the current methods for eliminating the influence of velocity anomaly bodies have obvious technical drawbacks: (1) It is difficult to accurately produce the time thickness map of the velocity anomaly body. This thickness map is obtained by interpreting the top and bottom interfaces of the velocity anomaly body on seismic data and then subtracting the grids of the top and bottom interfaces. The problem is that the resolution of seismic data is one-quarter wavelength, and usually the resolution is less than 30 meters. If the thickness of the velocity anomaly body is within 30 meters, it means that the top and bottom of the anomaly body are within the same phase, and it is very difficult to determine at which position of the seismic phase the bottom should be interpreted. Therefore, it is difficult to accurately produce the range and time thickness map of the velocity anomaly body. (2) The current methods need to statistically analyze the well point errors of all drill wells in the initial depth structure maps of the top and bottom surfaces of the velocity anomaly body and eliminate the errors irrelevant to the velocity anomaly body from the well point errors. It is very difficult to determine which errors are related to the velocity anomaly body and which are not, and there are human factors involved. (3) For the case where there are both low-velocity anomaly bodies and high-velocity anomaly bodies, the current methods need to produce two structural error compensation maps, making the mapping process cumbersome and further increasing the structural errors. Summary of the Invention

[0004] The present invention aims to solve the problems of related technical limitations to at least a certain extent. For this purpose, the present invention provides a time-depth conversion method, device, and storage medium for eliminating the influence of velocity anomalies, which can accurately perform time-depth conversion to eliminate the influence of velocity anomalies.

[0005] On the one hand, an embodiment of the present invention provides a time-depth conversion method for eliminating the influence of velocity anomalies, including the following steps:

[0006] Obtain 3D seismic data of the target area, and construct a time structure through seismic horizon interpretation based on the 3D seismic data; the time structure includes a seabed time structure, a limestone top time structure, and a target layer time structure;

[0007] Process the seabed time structure and the seawater acoustic wave velocity to obtain the seabed depth structure;

[0008] Perform linear fitting based on the time thickness and depth thickness of the pre-obtained drilling data, and fit the linear relationship between the first time thickness from the seabed to the limestone top and the first depth thickness;

[0009] Based on the first time thickness between the seabed time structure and the limestone top time structure, use the linear relationship to obtain the depth thickness from the seabed to the limestone top;

[0010] Construct the limestone top depth structure based on the seabed depth structure and the depth thickness from the seabed to the limestone top;

[0011] Based on the limestone top time structure and the target layer time structure, combine layer velocity processing to obtain the second depth thickness from the target layer to the limestone top, and construct the target layer depth structure based on the limestone top depth structure and the second depth thickness.

[0012] Optionally, constructing a time structure through seismic horizon interpretation based on 3D seismic data includes the following steps:

[0013] Based on the 3D seismic data, perform seismic horizon calibration according to the positive and negative polarities of the reflection coefficients corresponding to the seabed, limestone top, and target layer;

[0014] According to the calibration results of the seismic horizon calibration, perform lateral tracing interpretation on the seabed, limestone top, and target layer to obtain the interpretation data of the 3D structural horizon;

[0015] Import the interpretation data of the 3D structural horizon into a preset drawing software to draw the time structure.

[0016] Optionally, the seabed time structure is the two-way reflection time of the seabed; processing the seabed time structure and the seawater acoustic wave velocity to obtain the seabed depth structure includes the following steps:

[0017] Process half of the two-way reflection time of the seabed to obtain the one-way reflection time, and obtain the seabed depth structure based on the product of the one-way reflection time and the seawater acoustic wave velocity.

[0018] Optionally, performing linear fitting based on the time thickness and depth thickness of the pre-obtained drilling data, and fitting the linear relationship between the first time thickness from the seabed to the limestone top and the first depth thickness includes the following steps:

[0019] The time difference from the seabed to the limestone top is obtained based on the difference in reflection time between the seabed time structure and the limestone top time structure, and is used as the first time thickness;

[0020] The thickness from the seabed to the limestone top is obtained based on the difference in depth between the seabed depth structure and the first limestone top depth structure, and is used as the first depth thickness;

[0021] Perform linear fitting on the first time thickness and the first depth thickness corresponding to each measurement position in the target area to obtain a linear relationship.

[0022] Optionally, the limestone top depth structure is constructed based on the seabed depth structure and the depth thickness from the seabed to the limestone top, including the following steps:

[0023] The limestone top depth structure is constructed by adding the limestone top depth thickness to the seabed depth structure.

[0024] Optionally, the second depth thickness from the target layer to the limestone top is obtained by combining the limestone top time structure and the target layer time structure with layer velocity processing, including the following steps:

[0025] The second time thickness from the target layer to the limestone top is obtained based on the difference in reflection time between the limestone top time structure and the target layer time structure;

[0026] The second depth thickness from the target layer to the limestone top is obtained by multiplying the second time thickness by the layer velocity.

[0027] Optionally, the target layer depth structure is constructed based on the limestone top depth structure and the second depth thickness, including the following steps:

[0028] The target layer depth structure is constructed by adding the second depth thickness to the limestone top depth structure.

[0029] On the other hand, an embodiment of the present invention provides a time-depth conversion device for eliminating the influence of velocity anomalies, including:

[0030] A first module, configured to obtain three-dimensional seismic data of a target area, and construct a time structure based on the three-dimensional seismic data through seismic horizon interpretation; the time structure includes a seabed time structure, a limestone top time structure, and a target layer time structure;

[0031] A second module, configured to process the seabed time structure and the seawater acoustic wave velocity to obtain a seabed depth structure;

[0032] A third module, configured to perform linear fitting based on the time thickness and the depth thickness of pre-obtained drilling data, and fit the linear relationship between the first time thickness and the first depth thickness from the seabed to the limestone top;

[0033] The fourth module is used to obtain the depth thickness from the seabed to the limestone top based on the first time thickness between the seabed time structure and the limestone top time structure by using a linear relationship.

[0034] The fifth module is used to construct the limestone top depth structure based on the seabed depth structure and the depth thickness from the seabed to the limestone top.

[0035] The sixth module is used to process the layer velocity based on the limestone top time structure and the target layer time structure to obtain the second depth thickness from the target layer to the limestone top, and construct the target layer depth structure based on the limestone top depth structure and the second depth thickness.

[0036] On the other hand, an embodiment of the present invention provides an electronic device, including: a processor and a memory; the memory is used to store a program; the processor executes the program to implement the above time-depth conversion method for eliminating the influence of velocity anomalies.

[0037] On the other hand, an embodiment of the present invention provides a computer storage medium, in which a program executable by a processor is stored, and the program executable by the processor is used to implement the above time-depth conversion method for eliminating the influence of velocity anomalies when executed by the processor.

[0038] In the embodiment of the present invention, three-dimensional seismic data of a target area is obtained, and a time structure is constructed based on the three-dimensional seismic data through seismic horizon interpretation; the time structure includes a seabed time structure, a limestone top time structure, and a target layer time structure; the seabed depth structure is obtained based on the seabed time structure and the seawater acoustic velocity; linear fitting is performed based on the time thickness and depth thickness of pre-obtained drilling data, and the linear relationship between the first time thickness and the first depth thickness from the seabed to the limestone top is obtained by fitting; the depth thickness from the seabed to the limestone top is obtained based on the first time thickness between the seabed time structure and the limestone top time structure by using the linear relationship; the limestone top depth structure is constructed based on the seabed depth structure and the depth thickness from the seabed to the limestone top; the second depth thickness from the target layer to the limestone top is obtained by processing the layer velocity based on the limestone top time structure and the target layer time structure, and the target layer depth structure is constructed based on the limestone top depth structure and the second depth thickness. By avoiding the bottom structure of the interpreted velocity anomaly body and performing horizon interpretation of the limestone top through three-dimensional seismic data, there is an obvious wave impedance difference between the limestone top and the overlying strata, and the data structure can be realized more accurately; moreover, by linear fitting, the influence caused by individual errors is avoided. In the case of the simultaneous existence of a seawater low-velocity anomaly body and a reef limestone high-velocity anomaly body, the present invention does not need to make a structural error compensation map, and the time-depth conversion and structure mapping processes are relatively simple. The present invention can accurately implement time-depth conversion for eliminating the influence of velocity anomalies. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the technical solutions of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solutions of the present invention, and do not constitute a limitation to the technical solutions of the present invention.

[0040] Figure 1 It is a schematic diagram of an implementation environment for time-depth conversion to eliminate the influence of abnormal velocity provided by an embodiment of the present invention;

[0041] Figure 2 It is a schematic flowchart of a method for time-depth conversion to eliminate the influence of abnormal velocity provided by an embodiment of the present invention;

[0042] Figure 3 It is a schematic diagram of an example of a 3D seismic interpretation profile provided by an embodiment of the present invention;

[0043] Figure 4 It is a schematic diagram of an example of a seabed time structure provided by an embodiment of the present invention;

[0044] Figure 5 It is a schematic diagram of an example of a seawater depth structure provided by an embodiment of the present invention;

[0045] Figure 6 It is a schematic diagram of an example of the fitting relationship between the seismic reflection time difference and thickness from the seabed to the limestone top provided by an embodiment of the present invention;

[0046] Figure 7 It is a schematic diagram of an example of the time thickness from the seabed to the limestone top boundary provided by an embodiment of the present invention;

[0047] Figure 8 It is a schematic diagram of an example of the depth thickness from the seabed to the limestone top boundary provided by an embodiment of the present invention;

[0048] Figure 9 It is a schematic diagram of an example of the depth structure of the target layer provided by an embodiment of the present invention;

[0049] Figure 10 It is a schematic diagram of an example of the overall process of the method for time-depth conversion to eliminate the influence of abnormal velocity provided by an embodiment of the present invention;

[0050] Figure 11 It is a schematic diagram of the structure of a device for time-depth conversion to eliminate the influence of abnormal velocity provided by an embodiment of the present invention;

[0051] Figure 12 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. Detailed implementation manners

[0052] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0053] It should be noted that although the functional modules are divided in the system schematic diagram and the logical sequence is shown in the flowchart, in some cases, the steps shown or described can be executed in a different module division in the system or a different order in the flowchart. The terms "first / S100", "second / S200", etc. in the specification, claims and the above-mentioned drawings are used to distinguish similar objects and do not necessarily have to describe a specific order or sequence.

[0054] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present invention. The appearance of this phrase in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0055] It can be understood that the time-depth conversion method for eliminating the influence of abnormal velocity provided by the embodiments of the present invention can be applied to any computer device with data processing and computing capabilities, and this computer device can be various types of terminals or servers. When the computer device in the embodiment is a server, the server is an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms. Optionally, the terminal is a smart phone, a tablet computer, a notebook computer, a desktop computer, etc., but is not limited thereto.

[0056] For the convenience of understanding the technical solutions of the present invention, the following is an explanation of the technical feature proper nouns that may appear in the embodiments of the present invention:

[0057] As Figure 1 shown, it is a schematic diagram of an implementation environment provided by an embodiment of the present invention. Referring to Figure 1 , this implementation environment includes at least one terminal 102 and a server 101. The terminal 102 and the server 101 can be network-connected wirelessly or wiredly to complete data transmission and exchange.

[0058] The server 101 can be an independent physical server, a server cluster or a distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms.

[0059] In addition, the server 101 can also be a node server in a blockchain network. Among them, the blockchain is a new application mode of computer technologies such as distributed data storage, peer-to-peer transmission, consensus mechanism, and encryption algorithms.

[0060] The terminal 102 can be a smart phone, a tablet computer, a notebook computer, a desktop computer, a smart speaker, a smart watch, etc., but is not limited thereto. The terminal 102 and the server 101 can be directly or indirectly connected through wired or wireless communication methods, and the embodiments of the present invention do not make limitations here.

[0061] Exemplarily based on Figure 1 the shown implementation environment, the embodiments of the present invention provide a time-depth conversion method for eliminating the influence of velocity anomalies. Taking the application of this time-depth conversion method for eliminating velocity anomalies in the server 101 as an example for description, it can be understood that this time-depth conversion method for eliminating velocity anomalies can also be applied to the terminal 102.

[0062] Referring to Figure 2 , Figure 2 is a flowchart of the time-depth conversion method for eliminating the influence of velocity anomalies applied to the server provided by the embodiments of the present invention. The execution subject of this time-depth conversion method for eliminating velocity anomalies can be any of the foregoing computer devices (including servers or terminals). Referring to Figure 2 This method includes the following steps:

[0063] S100. Obtain three-dimensional seismic data of the target area, and construct a time structure through seismic horizon interpretation based on the three-dimensional seismic data;

[0064] Among them, the time structure includes a seabed time structure, a limestone top time structure, and a target layer time structure;

[0065] It should be noted that in some embodiments, the time structure constructed through seismic horizon interpretation based on 3D seismic data may include the following steps: Based on the 3D seismic data, seismic horizon calibration is performed according to the positive and negative polarities of the reflection coefficients corresponding to the seabed, the top of the limestone, and the target layer; according to the calibration results of the seismic horizon calibration, lateral tracking interpretation is performed on the seabed, the top of the limestone, and the target layer to obtain the interpretation data of the 3D structural horizon; the interpretation data of the 3D structural horizon is imported into a preset drawing software to draw the time structure.

[0066] Exemplarily, in some specific embodiments, the interpretation of 3D seismic data and the production of the time structure maps of the seabed, the top of the reef limestone, and the target layer can be achieved as follows:

[0067] Based on the fine calibration of the seismic horizon, determine the seismic phases of the seabed, the top of the reef limestone, and the top of the target layer, and perform 3D seismic data tracking interpretation on the determined seismic in-phase axes (as Figure 3 shown), and on the basis of seismic interpretation, produce the time structure maps of the seabed, the top of the reef limestone, and the target layer, etc.

[0068] (1) Fine calibration of seismic horizons: The fine calibration work of seismic horizons is completed according to well logging data (logging acoustic travel time curves and density curves), geological stratification data, and seismic volumes in the time domain. Since the seismic data used in the current research is generally positive polarity data, the seabed reflection is a very strong wave peak reflection. Seismic horizon calibration is mainly aimed at the reef limestone layer and the target layer. Compared with the surrounding rocks above and below, the reef limestone has obvious characteristics of high velocity and high wave impedance. Therefore, the top surface of the reef limestone has a law of increasing wave impedance from small to large, which is a positive reflection coefficient. In normal polarity seismic data, the reflection phase of the top surface of the reef limestone should correspond to the wave peak and be the same as the reflection phase of the seabed. Using the same method, the target layer can be calibrated. If the target layer has a positive reflection coefficient, it corresponds to the wave peak; if it has a negative reflection coefficient, it corresponds to the wave trough.

[0069] (2) Seismic horizon interpretation: According to the seismic horizon calibration results, make full use of the advantages of 3D seismic data, and use technical means such as time slices, arbitrary tangents, automatic tracking, and in-plane interpolation to perform lateral tracking interpretation on the top boundaries of the seabed, the top of the reef limestone, and the target layer, and finely interpret the 3D structural horizon. While interpreting, use 3D stereoscopic display to monitor the closure of the horizon in real time to effectively ensure the high precision of horizon interpretation.

[0070] (3) Production of time structure maps of the seabed, the top of the reef limestone, and the target layer: After completing the seismic interpretation, use the drawing software CPS3 of the GeoFrame interpretation platform to draw the time structure maps of the seabed (as Figure 4 shown, contour unit: milliseconds), the top of the reef limestone, and the target layer.

[0071] S200. Obtain the seabed depth structure based on the seabed time structure and the seawater acoustic wave velocity;

[0072] Among them, the depth structure includes the seabed depth structure and the first limestone top depth structure;

[0073] It should be noted that the seabed time structure is the two-way reflection time of the seabed; in some embodiments, obtaining the seabed depth structure based on the seabed time structure and the seawater acoustic wave velocity may include the following steps:

[0074] Process the half of the two-way reflection time of the seabed to obtain the one-way reflection time, and obtain the seabed depth structure based on the product of the one-way reflection time and the seawater acoustic wave velocity.

[0075] Exemplarily, in some specific embodiments, the seismic interpretation of the seabed horizon is the two-way reflection time of the seawater. Dividing the grid value of this two-way reflection time of the seabed by 2 can obtain the one-way reflection time of the seawater. Multiplying the one-way reflection time by the seawater velocity can obtain the depth structure of the seabed. Since the seawater velocity is about 1524 m / s, that is, 1.524 m / ms, so the time structure of the above seismic interpretation can be divided by 2 and then multiplied by 1.524 to obtain the depth structure diagram of the seawater (as Figure 5 shown, contour unit: ms). It should also be noted that the area between the seabed and the limestone top is mainly composed of sediments and sedimentary rocks. Based on the principle of the relationship between relevant velocity and time, the depth structure of the limestone top (i.e., the first limestone top depth structure) can be further calculated.

[0076] S300. Perform linear fitting based on the time thickness and depth thickness of the pre-obtained drilling data, and fit the linear relationship between the first time thickness and the first depth thickness from the seabed to the limestone top;

[0077] It should be noted that in some embodiments, performing linear fitting based on the time thickness and depth thickness of the pre-obtained drilling data, and fitting the linear relationship between the first time thickness and the first depth thickness from the seabed to the limestone top may include the following steps: Obtain the time difference from the seabed to the limestone top as the first time thickness according to the difference in reflection time between the seabed time structure and the limestone top time structure; Obtain the thickness from the seabed to the limestone top as the first depth thickness according to the difference in depth between the seabed depth structure and the first limestone top depth structure; Perform linear fitting on the first time thickness and the first depth thickness corresponding to each measurement position in the target area to obtain the linear relationship.

[0078] In some specific application scenarios, performing linear fitting based on the time thickness and depth thickness of the pre-obtained drilling data can specifically perform linear fitting based on the seismic reflection time thickness and the actual drilling depth thickness at the location where the drilling is located.

[0079] Exemplarily, in some specific embodiments, the relationship between the seismic reflection time difference from the seabed to the top of the limestone and the thickness is statistically analyzed, and the fitting linear relationship can be achieved as follows:

[0080] Table 1 below is a statistical table of the relationship between the seismic reflection time difference from the seabed to the top of the limestone in a certain oilfield and the thickness. It is statistically found that there is a very good linear relationship between the two. The fitting linear relationship is: y = 1.1892x + 85.2935, and the correlation coefficient reaches 94.01% (as Figure 6 shown).

[0081] Table 1

[0082]

[0083]

[0084] S400. Based on the first time thickness between the seabed time structure and the top of the limestone time structure, the depth thickness from the seabed to the top of the limestone is obtained by using the linear relationship;

[0085] In some specific application scenarios, step S400 can be implemented as: based on the seabed time structure and the top of the limestone time structure, the time thickness from the seabed to the top of the limestone is obtained, and combined with the relationship between the time difference from the seabed to the top of the limestone and the depth thickness (i.e., the linear relationship) fitted from the drilling data, the sedimentary rock thickness from the seabed to the top of the limestone is obtained.

[0086] Exemplarily, in some specific embodiments, taking the foregoing linear relationship as an example, the time thickness from the seabed to the top of the limestone is obtained by subtracting the seabed time grid data from the top of the limestone time grid data obtained from the three-dimensional seismic data interpretation, and then the depth thickness from the seabed to the top of the limestone is calculated using the linear relationship y = 1.1892x + 85.2935. In the relationship, x represents the time thickness from the seabed to the top of the limestone (as Figure 7 shown, the unit of the isoline: meter), and y represents the depth thickness from the seabed to the top of the limestone (as Figure 8 shown, the unit of the isoline: meter).

[0087] S500. Based on the seabed depth structure and the depth thickness from the seabed to the top of the limestone, the top of the limestone depth structure is constructed;

[0088] It should be noted that in some embodiments, step S500 may include the following steps: adding the depth thickness of the top of the limestone to the seabed depth structure to construct the top of the limestone depth structure.

[0089] Exemplarily, in some specific embodiments, the depth structure of the limestone top can be obtained by adding the seabed depth structure to the depth thickness from the seabed to the limestone top, which can be implemented as follows: adding the seabed depth structure obtained in step S200 to the depth thickness from the seabed to the limestone top obtained in step S400 to obtain the depth structure of the limestone top boundary (i.e., the depth structure of the limestone top).

[0090] S600. Based on the time structure of the limestone top and the time structure of the target layer, combined with the layer velocity, the second depth thickness from the target layer to the limestone top is processed, and based on the depth structure of the limestone top and the second depth thickness, the depth structure of the target layer is constructed.

[0091] It should be noted that in some embodiments, processing the layer velocity in combination with the time structures of the limestone top and the target layer to obtain the second depth thickness from the target layer to the limestone top may include the following steps: obtaining the second time thickness from the target layer to the limestone top according to the difference in reflection times between the time structure of the limestone top and the time structure of the target layer; obtaining the second depth thickness from the target layer to the limestone top by multiplying the second time thickness by the layer velocity. Among them, since the layer velocity already takes into account the two-way reflection time of the seabed, the time thickness here does not need to be divided by 2.

[0092] It should also be noted that in some embodiments, constructing the depth structure of the target layer based on the depth structure of the limestone top and the second depth thickness may include the following steps: adding the second depth thickness to the depth structure of the limestone top to construct the depth structure of the target layer.

[0093] Exemplarily, in some specific embodiments, the thickness from the target layer to the limestone top is obtained by using the layer velocity and the seismic reflection time difference, and adding the depth structure of the limestone top, the depth structure of the target layer can be obtained as follows:

[0094] The time thickness from the target layer to the limestone top can be obtained by subtracting the time grid data of the limestone top from the time grid data of the target layer obtained from the three-dimensional seismic data interpretation, and multiplying this time thickness by the layer velocity of this layer to obtain the depth thickness from the target layer to the limestone top. Adding the depth thickness from the target layer to the limestone top to the depth structure of the limestone top can obtain the depth structure of the target layer (as Figure 9 shown, contour unit: meters).

[0095] To explain the principle of the technical solution of the present invention in detail, the overall process of the present invention will be described below in combination with some specific embodiments. It is easy to understand that the following is an explanation of the technical principle of the present invention and should not be regarded as a limitation of the present invention.

[0096] First of all, it should be noted that the method for eliminating the influence of velocity anomaly bodies can be to create a time thickness map of the velocity anomaly bodies, and statistically analyze the well point errors of all the drilled wells in the initial depth structure maps of the top and bottom surfaces of the velocity anomaly bodies; eliminate the errors unrelated to the velocity anomaly bodies from the well point errors, establish a linear regression formula; calculate the constructed error compensation map; calculate the compensated depth maps of each target layer below the velocity anomaly bodies in the structure according to the constructed error compensation map, and obtain the depth structure maps of each target layer after correction according to the compensated depth maps.

[0097] Among them, the current methods for eliminating the influence of velocity anomaly bodies have obvious technical drawbacks. Based on the current time-depth conversion technology for eliminating the influence of velocity anomaly bodies, there are drawbacks such as inaccurate grasp of the bottom seismic phase of the anomaly bodies and cumbersome production of depth structure error compensation maps. The present invention provides a time-depth conversion method for eliminating the influence of low-velocity anomalies in seawater and high-velocity anomalies in limestone, as Figure 10 shown, which can be realized through the following process:

[0098] 1. Interpretation of 3D seismic data and production of time structure maps of the seabed, reef limestone top and target layers:

[0099] Based on the fine calibration of seismic horizons, determine the seismic phases of the seabed, reef limestone top and target layer top, and conduct 3D seismic data tracing and interpretation of the determined seismic in-phase axes (as Figure 3 shown). On the basis of seismic interpretation, produce time structure maps of the seabed, reef limestone top and target layers, etc.

[0100] (1) Fine calibration of seismic horizons: The fine calibration work of seismic horizons is completed according to well logging data (logging acoustic travel time curves and density curves), geological stratification data, and seismic volumes in the time domain. Since the seismic data used in the current research is generally positive polarity data, the seabed reflection is a very strong wave peak reflection. Seismic horizon calibration mainly targets reef limestone layers and target layers. Compared with the upper and lower surrounding rocks, reef limestone has obvious characteristics of high velocity and high wave impedance. Therefore, the top surface of reef limestone has a law of wave impedance changing from small to large, which is a positive reflection coefficient. In normal polarity seismic data, the reflection phase of the top surface of reef limestone should correspond to the wave peak and be the same as the reflection phase of the seabed. Using the same method, the target layer can be calibrated. If the target layer has a positive reflection coefficient, it corresponds to the wave peak; if it has a negative reflection coefficient, it corresponds to the wave trough.

[0101] (2) Seismic horizon interpretation: According to the seismic horizon calibration results, make full use of the advantages of 3D seismic data, and use technical means such as time slices, arbitrary tangents, automatic tracking, and in-plane interpolation to conduct lateral tracking and interpretation of the top boundaries of the seabed, reef limestone top and target layers, finely interpret the 3D structural horizons, and use 3D stereoscopic display to monitor the closure of the horizons in real time during the interpretation to effectively ensure the high precision of horizon interpretation.

[0102] (3) Production of time structure maps of the seabed, reef limestone top and target layer: After seismic interpretation is completed, using the drawing software CPS3 of the GeoFrame interpretation platform, time structure maps of the seabed (as shown in Figure 4 , contour unit: milliseconds), reef limestone top and target layer are drawn.

[0103] 2. Obtaining the seabed depth structure:

[0104] The seabed layer position in the above seismic interpretation is the two-way reflection time of the seabed of seawater. Dividing this two-way reflection time grid value of the seabed by 2 can obtain the one-way reflection time of seawater. Multiplying the one-way reflection time by the seawater velocity can obtain the depth structure of the seabed. Since the seawater velocity is about 1524 m / s, that is, 1.524 m / ms, so the time structure obtained from the above seismic interpretation can be divided by 2 and then multiplied by 1.524 to obtain the depth structure map of seawater (as shown in Figure 5 , contour unit: milliseconds). It should also be noted that the area between the seabed and the limestone top is mainly composed of sediments and sedimentary rocks. Based on the relevant velocity-time relationship principle, the depth structure of the limestone top can be further calculated.

[0105] 3. Statistically analyze the relationship between the seismic reflection time difference and thickness from the seabed to the limestone top, and fit a linear relationship formula:

[0106] The above Table 1 is a statistical table of the relationship between the seismic reflection time difference and thickness from the seabed to the limestone top of a certain oilfield. It is statistically found that there is a very good linear relationship between the two. The fitted linear relationship formula is: y = 1.1892x + 85.2935, and the correlation coefficient reaches 94.01% (as shown in Figure 6 ).

[0107] 4. According to the fitted linear relationship formula, obtain the depth thickness map from the seabed to the limestone top:

[0108] Subtract the seabed time grid data from the limestone top time grid data obtained from the three-dimensional seismic data interpretation to obtain the time thickness from the seabed to the limestone top, and then use the linear relationship formula y = 1.1892x + 85.2935 for calculation to obtain the depth thickness from the seabed to the limestone top. In the formula, x represents the time thickness from the seabed to the limestone top (as shown in Figure 7 , contour unit: meters), and y represents the depth thickness from the seabed to the limestone top (as shown in Figure 8 , contour unit: meters).

[0109] 5. Add the seabed depth structure to the depth thickness from the seabed to the limestone top to obtain the limestone top depth structure:

[0110] Add the seabed depth structure obtained in step 2 to the depth thickness from the seabed to the limestone top obtained in step 4 to obtain the depth structure of the limestone top boundary.

[0111] 6. Calculate the thickness from the target layer to the top of the limestone by using the interval velocity and seismic reflection time difference, and add the depth structure of the top of the limestone to obtain the depth structure of the target layer:

[0112] Subtract the time grid data of the top of the limestone from the time grid data of the target layer obtained from the 3D seismic data interpretation to get the time thickness from the target layer to the top of the limestone. Multiply this time thickness by the interval velocity of this layer to obtain the depth thickness from the target layer to the top of the limestone. Adding the depth thickness from the target layer to the top of the limestone to the depth structure of the top of the limestone can obtain the depth structure of the target layer (as Figure 9 shown, contour unit: meters).

[0113] In summary, the present invention optimizes the time-depth conversion from three aspects: First, avoid the bottom structure of the interpreted velocity anomaly body. Because compared with the bottom, the top of the velocity anomaly body is much easier to grasp. There is an obvious wave impedance difference between the top and the overlying strata, which is generally the position of the wave peak (or wave trough) of the interpreted seismic phase. Second, minimize the influence of human factors, and each step has a theoretical basis for feasibility. Third, in the case of the coexistence of a seawater low-velocity anomaly body and a reef limestone high-velocity anomaly body, there is no need to make a structural error compensation map, and the time-depth conversion and structure mapping processes are relatively simple.

[0114] On the other hand, as Figure 11 shown, an embodiment of the present invention provides a time-depth conversion device 900 for eliminating the influence of velocity anomalies, which may include:

[0115] A first module 901, configured to obtain 3D seismic data of a target area, and construct a time structure through seismic horizon interpretation based on the 3D seismic data; the time structure includes a seabed time structure, a top-of-limestone time structure, and a target-layer time structure;

[0116] A second module 902, configured to process the seabed time structure and the seawater acoustic velocity to obtain a seabed depth structure;

[0117] A third module 903, configured to perform linear fitting based on the time thickness and depth thickness of pre-obtained drilling data, and fit to obtain a linear relationship between the first time thickness and the first depth thickness from the seabed to the top of the limestone;

[0118] A fourth module 904, configured to obtain the depth thickness from the seabed to the top of the limestone by using the linear relationship based on the first time thickness between the seabed time structure and the top-of-limestone time structure;

[0119] A fifth module 905, configured to construct a top-of-limestone depth structure based on the seabed depth structure and the depth thickness from the seabed to the top of the limestone;

[0120] The sixth module 906 is used to process the combined layer velocity based on the limestone top time structure and the target layer time structure to obtain the second depth thickness from the target layer to the limestone top, and construct the target layer depth structure based on the limestone top depth structure and the second depth thickness.

[0121] The content of the method embodiments of the present invention is applicable to the device embodiments of the present invention. The functions specifically implemented by the device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those of the above method.

[0122] On the other hand, the embodiments of the present invention also provide an electronic device, which includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the above time-depth conversion method for eliminating the influence of velocity anomalies. The electronic device can be any intelligent terminal including a tablet computer, an in-vehicle computer, etc.

[0123] It can be understood that the content in the above method embodiments is applicable to the device embodiments of the present invention. The functions specifically implemented by the device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those of the above method embodiments.

[0124] As Figure 12 shown, Figure 12 Figure 16 schematically shows the hardware structure of an electronic device 1000 according to another embodiment. The electronic device 1000 includes:

[0125] A processor 1001, which can be implemented in a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, etc., and is used to execute relevant programs to implement the technical solutions provided by the embodiments of the present invention;

[0126] A memory 1002, which can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM), etc. The memory 1002 can store an operating system and other application programs. When implementing the technical solutions provided in the embodiments of this specification through software or firmware, the relevant program codes are stored in the memory 1002 and are called by the processor 1001 to execute the network node population optimization method of the embodiments of the present invention;

[0127] An input / output interface 1003, which is used to implement information input and output;

[0128] A communication interface 1004 for implementing communication interaction between this device and other devices, which can achieve communication through a wired manner (such as USB, network cable, etc.) or through a wireless manner (such as mobile network, WIFI, Bluetooth, etc.);

[0129] A bus 1005 for transmitting information between various components of the device (such as a processor 1001, a memory 1002, an input / output interface 1003, and a communication interface 1004);

[0130] Among them, the processor 1001, the memory 1002, the input / output interface 1003, and the communication interface 1004 are communicatively connected to each other inside the device through the bus 1005.

[0131] The electronic device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0132] The content of the method embodiments of the present invention is applicable to the electronic device embodiments of the present invention. The functions specifically implemented by the electronic device embodiments of the present invention are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those of the above methods.

[0133] Another aspect of the embodiments of the present invention further provides a computer-readable storage medium, and the storage medium stores a program, and the program is executed by a processor to implement the foregoing method.

[0134] It should be noted that the computer-readable medium shown in the embodiments of the present invention can be a computer-readable signal medium, a computer-readable storage medium, or any combination of the two. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of the computer-readable storage medium can include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a flash memory, an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present invention, the computer-readable storage medium can be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, apparatus, or device. In the present invention, the computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable medium other than the computer-readable storage medium, and this computer-readable medium can send, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted by any appropriate medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0135] The content of the method embodiments of the present invention is applicable to this computer-readable storage medium embodiment. The functions specifically implemented by this computer-readable storage medium embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those of the above method.

[0136] The embodiments of the present invention also disclose a computer program product or a computer program. The computer program product or the computer program includes computer instructions, and these computer instructions are stored in a computer-readable storage medium. The processor of the computer device can read the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the previous method.

[0137] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, a segment of a program, or a portion of code that contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions noted in the blocks may occur in a different order than noted in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram or flowchart, and combinations of blocks in the block diagram or flowchart, can be implemented by a dedicated hardware-based system that performs the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0138] It should be noted that although several modules of devices for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to embodiments of the present invention, the features and functions of two or more of the above-described modules or units can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0139] From the description of the above embodiments, those skilled in the art can easily understand that the example embodiments described herein can be implemented by software, or by a combination of software and necessary hardware. Therefore, the technical solutions according to the embodiments of the present invention can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes several instructions to enable a computing device (such as a personal computer, a server, a touch terminal, or a network device, etc.) to execute the method according to the embodiments of the present invention.

[0140] In some alternative embodiments, the functions / operations mentioned in the block diagram may not occur in the order mentioned in the operation illustration. For example, depending on the functions / operations involved, two consecutive blocks shown may actually be executed substantially simultaneously, or the blocks can sometimes be executed in the reverse order. In addition, the embodiments presented and described in the flowcharts of the present invention are provided by way of example for the purpose of providing a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logical flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and in which sub-operations described as part of a larger operation are executed independently.

[0141] In addition, although the present invention has been described in the context of functional modules, it should be understood that, unless otherwise stated to the contrary, one or more of the functions and / or features may be integrated in a single physical device and / or software module, or one or more functions and / or features may be implemented in separate physical devices or software modules. It should also be understood that a detailed discussion of the actual implementation of each module is not necessary for understanding the present invention. Rather, considering the attributes, functions, and internal relationships of the various functional modules in the devices disclosed herein, the actual implementation of the modules will be understood within the ordinary skills of an engineer. Therefore, those skilled in the art can implement the present invention as set forth in the claims without undue experimentation. It should also be understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of the present invention, which is determined by the full scope of the appended claims and their equivalents.

[0142] If a function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0143] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a defined sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution device, apparatus, or equipment (such as a computer-based device, a device including a processor, or other devices that can fetch instructions from and execute instructions by the instruction execution device, apparatus, or equipment), or in combination with these instruction execution devices, apparatuses, or equipment. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by or in combination with an instruction execution device, apparatus, or equipment.

[0144] More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection (electronic device) having one or more wirings, a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable media can even be paper or other suitable media on which a program can be printed, as the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other suitable processing as necessary, and then stored in a computer memory.

[0145] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution device. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application-specific integrated circuits having suitable combinational logic gate circuits, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0146] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0147] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.

[0148] The above has specifically described the preferred embodiments of the present invention, but the present invention is not limited to the embodiments. Those skilled in the art can also make various equivalent deformations or substitutions without departing from the spirit of the present invention, and these equivalent deformations or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A time-depth conversion method for eliminating the influence of abnormal velocity, characterized in that, Including the following steps: Obtain 3D seismic data of the target area, and construct a time structure through seismic horizon interpretation based on the 3D seismic data; the time structure includes a seabed time structure, a limestone top time structure, and a target layer time structure; Process the seabed time structure and the seawater acoustic velocity to obtain a seabed depth structure; Perform linear fitting based on the time thickness and depth thickness of pre-obtained drilling data, and fit the linear relationship between the first time thickness from the seabed to the limestone top and the first depth thickness; Based on the first time thickness between the seabed time structure and the limestone top time structure, use the linear relationship to obtain the depth thickness from the seabed to the limestone top; Construct a limestone top depth structure based on the seabed depth structure and the depth thickness from the seabed to the limestone top; Based on the limestone top time structure and the target layer time structure, combine layer velocity processing to obtain the second depth thickness from the target layer to the limestone top, and construct a target layer depth structure based on the limestone top depth structure and the second depth thickness.

2. The time-depth conversion method for eliminating the influence of abnormal elimination speed according to claim 1, characterized in that The constructing the time structure through seismic horizon interpretation based on the 3D seismic data includes the following steps: Based on the 3D seismic data, perform seismic horizon calibration according to the positive and negative polarities of the reflection coefficients corresponding to the seabed, limestone top, and target layer; According to the calibration results of the seismic horizon calibration, perform lateral tracing interpretation on the seabed, the limestone top, and the target layer to obtain interpretation data of the 3D structural horizon; Import the interpretation data of the 3D structural horizon into a preset drawing software to draw the time structure.

3. The time-depth conversion method for eliminating the influence of abnormal elimination speed according to claim 1, characterized in that The seabed time structure is the two-way reflection time of the seabed; the processing the seabed time structure and the seawater acoustic velocity to obtain a seabed depth structure includes the following steps: Process half of the two-way reflection time of the seabed to obtain a one-way reflection time, and obtain the seabed depth structure based on the product of the one-way reflection time and the seawater acoustic velocity.

4. The time-depth conversion method for eliminating the influence of abnormal elimination speed according to claim 1, characterized in that The performing linear fitting based on the time thickness and depth thickness of pre-obtained drilling data, and fitting the linear relationship between the first time thickness from the seabed to the limestone top and the first depth thickness includes the following steps: Obtain the time difference from the seabed to the limestone top as the first time thickness according to the difference in reflection time between the seabed time structure and the limestone top time structure; Obtain the thickness from the seabed to the limestone top as the first depth thickness according to the difference in depth between the seabed depth structure and the first limestone top depth structure; Perform linear fitting on the first time thickness and the first depth thickness corresponding to each measurement position in the target area to obtain the linear relationship.

5. The time-depth conversion method for eliminating the influence of abnormal elimination speed according to claim 1, characterized in that The constructing the limestone top depth structure based on the seabed depth structure and the depth thickness from the seabed to the limestone top includes the following steps: Add the depth thickness from the seabed to the limestone top to the seabed depth structure to construct the limestone top depth structure.

6. The time-depth conversion method for eliminating the influence of abnormal elimination speed according to claim 1, wherein, The combining layer velocity processing based on the limestone top time structure and the target layer time structure to obtain the second depth thickness from the target layer to the limestone top includes the following steps: The second time thickness from the target layer to the limestone top is obtained according to the difference in reflection time between the limestone top time structure and the target layer time structure; The second depth thickness from the target layer to the limestone top is obtained according to the product of the second time thickness and the interval velocity.

7. The time-depth conversion method for eliminating the influence of abnormal elimination speed according to claim 1, wherein The construction of the target layer depth structure based on the limestone top depth structure and the second depth thickness includes the following steps: The target layer depth structure is constructed by adding the second depth thickness to the limestone top depth structure.

8. A time-depth conversion device for eliminating the influence of abnormal velocity, characterized in that It includes: A first module, configured to obtain 3D seismic data of a target area, and construct a time structure through seismic horizon interpretation based on the 3D seismic data; the time structure includes a seabed time structure, a limestone top time structure, and a target layer time structure; A second module, configured to process the seabed depth structure based on the seabed time structure and the seawater acoustic velocity; A third module, configured to perform linear fitting based on the time thickness and depth thickness of pre-obtained drilling data, and fit the linear relationship between the first time thickness from the seabed to the limestone top and the first depth thickness; A fourth module, configured to obtain the depth thickness from the seabed to the limestone top by using the linear relationship based on the first time thickness between the seabed time structure and the limestone top time structure; A fifth module, configured to construct the limestone top depth structure based on the seabed depth structure and the depth thickness from the seabed to the limestone top; A sixth module, configured to process the second depth thickness from the target layer to the limestone top based on the limestone top time structure and the target layer time structure in combination with the interval velocity, and construct the target layer depth structure based on the limestone top depth structure and the second depth thickness.

9. An electronic device, characterized in that, It includes a processor and a memory; The memory is used to store programs; The processor executes the program to implement the method according to any one of claims 1 to 7.

10. A computer storage medium storing a program executable by a processor, characterized in that, The program executable by the processor, when executed by the processor, is used to implement the method according to any one of claims 1 to 7.

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