A seismic time-depth dual-domain calibration method and device based on VSP logging
The pre-stack depth migration seismic time-depth dual-domain calibration method based on VSP logging solves the problem of large well-seismic calibration error, realizes high-precision well-seismic calibration under complex geological conditions, and improves the efficiency and accuracy of exploration and development.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2024-12-09
- Publication Date
- 2026-06-09
AI Technical Summary
Existing technologies struggle to achieve standardized and high-precision well-seismic calibration, especially under complex geological conditions. Sonic logging curves are affected by various factors, leading to large calibration errors and making it difficult to accurately delineate small layers and favorable reservoirs.
A time-depth dual-domain calibration method based on VSP logging is adopted, which combines VSP logging data with pre-stack depth migration seismic data. Accurate calibration in the time and depth domains is achieved through VSP corridor stacking profiles, and high-precision layer velocity conversion and logging information are used for matching.
It improves the precision and accuracy of wellbore calibration, enabling precise segmentation of sub-layers and favorable reservoirs under complex geological conditions, thereby increasing exploration and development efficiency and providing a basis for geological research and drilling geological guidance.
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Figure CN122172304A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of seismic calibration, and in particular to a seismic time-depth dual-domain calibration method and apparatus based on VSP logging. Background Technology
[0002] In recent years, with the continuous deepening of exploration and development, the medium-deep shale oil, thin beach-bar sands, medium-deep fans, and deep Paleozoic buried hills in Shengli Oilfield have become important reservoir-enhancing and production-generating strata. These strata generally possess geological characteristics such as large burial depth, complex structures, rapid changes in stratigraphic dip, varied lithology, and rapid changes in vertical and horizontal velocities. However, shale oil typically requires long horizontal wells for large-scale, cost-effective development; beach-bar sands and fan edges are thin, requiring fine-grained sub-layer subdivision; and Paleozoic buried hills have complex structures and rapid velocity changes, demanding precise subdivision of favorable reservoir sections. Therefore, the complex geological conditions and the high precision required for sub-layer and favorable reservoir subdivision place higher demands on well-seismic calibration. Furthermore, well-seismic calibration is fundamental to geological and seismic research, and its precision affects the accuracy of the overall reservoir description. Therefore, high-precision well-seismic calibration is of great significance for exploration and development.
[0003] Currently, some professional software in the industry primarily uses sonic logging curves to calculate reflection coefficients, which are then convolved with wavelet transects near the well to obtain a synthetic transect. This synthetic transect is then compared and calibrated with the actual transect to achieve a precise calibration of the target layer. Technically, this method relies heavily on sonic logging curves, which are significantly affected by wellbore diameter quality, mud soaking, sonic energy attenuation, and curve measurement quality, making it difficult to obtain accurate subsurface velocity sequences. Furthermore, the calibration process is susceptible to significant errors caused by subjective drift, stretching, and compression, making quality control difficult and resulting in inaccurate well-seismic calibration and time-depth relationships. From a geological perspective, deep, thin-layered beach-bar sandstone is difficult to calibrate accurately with low-resolution seismic data. Medium- to deep buried hill carbonate rocks, igneous rocks, gypsum-salt rocks, and conglomerate bodies exhibit rapid velocity changes, making sonic synthesis recording highly susceptible to subjective influences and challenging to quality control. Deep shale oil production primarily utilizes a three-dimensional horizontal well development model, which has low seismic resolution and small target box thickness, requiring high precision in well-seismic calibration. Therefore, there is currently no standardized and highly accurate well-seismic calibration model.
[0004] Therefore, those skilled in the art are dedicated to developing a standardized and highly accurate well-seismic calibration mode. Summary of the Invention
[0005] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a standardized and highly accurate well-vibration calibration mode.
[0006] We believe that pre-stack depth migration (PSM) is the most effective means of accurately obtaining images of the interior of complex structures, and is a true full-3D pre-stack imaging technique. With the widespread use of PSM seismic logging, the calibration of depth-domain and time-domain seismic profiles is becoming increasingly important. VSP logging accurately reflects the variation of seismic wave propagation velocity in the formation, offering high precision and directly obtaining the seismic waveform characteristics of time-depth relationships and formation combinations. Simultaneously, it carries accurate depth information, providing rich data and improving the accuracy of well-seismic calibration in both the time and depth domains.
[0007] To improve the accuracy of wellbore calibration and enhance the efficiency of exploration and development, this invention proposes a pre-stack depth migration seismic time-depth dual-domain calibration method based on VSP logging, implemented in software. This method enables geological researchers, geophysical interpreters, and drilling geology guides to accurately and quickly identify target layers in time-depth dual-domain seismic profiles, providing a basis for their respective work. This facilitates structural interpretation, reservoir prediction, and real-time guidance for drilling geology guide trajectories.
[0008] In a preferred embodiment of the present invention, a time-depth dual-domain seismic calibration method based on VSP logging is implemented, comprising the following steps: obtaining a time-domain VSP profile using VSP logging acquisition and processing; converting the time-domain VSP profile to a depth-domain VSP profile using high-precision layer velocities obtained from VSP logging acquisition; calibrating using the VSP corridor stacked time-domain profile and pre-stack depth-biased time-domain seismic data to obtain the correspondence between the VSP time-domain profile and the time-domain seismic data, and placing the pre-stack depth-biased time-domain seismic data to the right of the time axis of the VSPlog stacked profile; calibrating using the VSP corridor stacked depth-domain profile and pre-stack depth-biased depth-domain seismic data to obtain the correspondence between the phase axes of the pre-stack depth-biased time-domain and depth-domain seismic reflection facies and geological information, and placing them laterally on the depth axis of the VSP corridor stacked profile; and outputting a time-depth dual-domain seismic calibration map based on VSP logging, including time and depth axes, based on software engineering.
[0009] Furthermore, the step of obtaining the time-domain VSP profile through VSP logging acquisition and processing involves obtaining a VSP corridor overlay profile through VSP logging acquisition and processing, and then cutting and overlaying it to obtain the time-domain VSP profile. The specific steps include:
[0010] Step 1: Static time shift and alignment of VSP uplink waves. The specific method is as follows: VSP two-way vertical time T = initial arrival time Tfb + uplink propagation time Tup, that is, the time of each channel plus the initial arrival time of the downlink wave, so that the uplink waves are aligned according to their two-way time from the ground surface to the interface.
[0011] Step 2, corridor excision, is specifically performed by excising a section of corridor along the first arrival wave, preserving as much of the first reflected wave as possible, and removing multiple reflected waves and noise.
[0012] Step 3, corridor overlay, is specifically performed by vertically overlaying and summing the cut corridors to obtain the time-domain VSPlog overlay profile.
[0013] Step 4: Place the time-domain VSPlog overlay profile to the right of the VSP corridor overlay profile, aligning its vertical time axis with it.
[0014] Furthermore, when converting the time-domain VSP profile to the depth-domain VSP profile using the high-precision layer velocities obtained from VSP logging, the average velocity and layer velocity can be calculated from the VSP arrival time, as shown in the following formula:
[0015] The formula for calculating the velocity of the VSP layer is as follows:
[0016]
[0017] Formula for calculating average speed:
[0018] T i
[0019] Where X is the vertical distance between the trigger point and the wellhead, i.e., the well-source distance; H is the formation depth; and T is the first arrival time.
[0020] The time-domain VSP corridor overlay profile is converted to the depth-domain corridor overlay profile based on the average velocity.
[0021] Furthermore, it also includes the step of creating a depth domain single-well columnar section, wherein the depth domain single-well columnar section includes one or more of the following: depth, logging curves, logging interpretation results, lithology, and geological stratification information.
[0022] Furthermore, the logging curve can be a curve reflecting lithology, such as spontaneous potential or spontaneous gamma curve, or a curve reflecting physical properties, such as sonic transit time, density, neutron curve, or resistivity curve reflecting oil content.
[0023] Furthermore, the well logging interpretation results are lithological or oil-bearing results interpreted based on the well logging curves.
[0024] Furthermore, the geological stratification described is the geological stratification commonly used in this area for exploration and development of the target layer, and can be accurate to the sub-layer.
[0025] Furthermore, the lithology referred to is the lithology established by logging or core samples.
[0026] Furthermore, the depth domain single-well column chart is placed laterally on the depth coordinate axis of the VSP corridor overlay profile, and its depth is completely consistent with that of the VSP corridor overlay depth domain profile. The VSP corridor overlay depth domain profile is loaded with one or more of the following: well logging curves, well logging interpretation results, lithology, and geological stratification information.
[0027] In another embodiment of the present invention, a seismic time-depth dual-domain calibration device based on VSP logging is provided, including at least one processor and a memory storing computer-executable instructions to implement the steps of any of the aforementioned methods.
[0028] Technical effect
[0029] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description
[0030] Figure 1 This specification provides a seismic time-depth dual-domain calibration map based on VSP logging.
[0031] Figure 2 This document provides a flowchart of a seismic time-depth dual-domain calibration method based on VSP logging. Detailed Implementation
[0032] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments in this specification, and not all of them. All other embodiments obtained by those skilled in the art based on one or more embodiments of this specification without creative effort should fall within the scope of protection of the embodiments in this specification.
[0033] To better illustrate the feasibility and practicality of the embodiments of this application, this specification also provides one specific embodiment and another specific embodiment. The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. Specific details can be found in the descriptions of the relevant embodiments, which will not be repeated here. In some cases, the actions or steps described in the claims can be performed in a different order than in the embodiments and still achieve the desired result. Furthermore, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result.
[0034] In one instance, the following was implemented: Figure 1This example illustrates a seismic time-depth dual-domain calibration map based on VSP logging; the example uses... Figure 2 The flowchart shown implements seismic time-depth dual-domain calibration based on VSP logging. The specific implementation steps are as follows:
[0035] S1. VSP corridor overlay profiles are obtained by collecting and processing VSP logging data, and time-domain VSP profiles are obtained by cutting and overlaying.
[0036] (1) Static time shift and alignment of VSP uplink wave
[0037] VSP two-way vertical time T = first arrival time Tfb + uplink propagation time Tup
[0038] That is, by adding the arrival time of the downwave to the arrival time of each wave, the upwaves are arranged according to their two-way travel time from the surface to the interface.
[0039] (2) Corridor cut-off: A section of corridor is cut off parallel to the first arrival wave, preserving as much of the first reflected wave as possible and removing multiple reflected waves and noise.
[0040] (3) Corridor superposition: The time domain VSPlog superposition profile can be obtained by vertically superimposing and summing the cut corridors.
[0041] (4) Place the time domain VSPlog overlay profile to the right of the VSP corridor overlay profile, with its vertical time axis aligned with it.
[0042] S2. Utilize the high-precision layer velocity obtained from VSP logging to convert the time-domain VSP profile to the depth-domain VSP profile.
[0043] The average velocity and layer velocity can be calculated from the VSP arrival time, using the following formula:
[0044] The formula for calculating the velocity of the VSP layer is as follows:
[0045]
[0046] Formula for calculating average speed:
[0047]
[0048] X: is the vertical distance between the excitation point and the wellhead, i.e., the well-source distance;
[0049] H: Depth of the formation;
[0050] T: arrival time.
[0051] Similarly, by performing time-depth conversion based on average velocity, the time-domain VSP corridor overlay profile can be converted to the depth-domain corridor overlay profile.
[0052] S3. The VSP corridor time-domain profile and pre-stack depth-biased time-domain seismic data are used for calibration to obtain the correspondence between the VSP time-domain profile and the time-domain seismic data. The pre-stack depth-biased time-domain seismic data is then placed to the right of the time axis of the VSPlog stack profile.
[0053] S4. Create a depth domain single-well columnar section with depth, logging curves, logging interpretation results, lithology, and geological stratification (down to the smallest layer).
[0054] Well logging curves: mainly curves reflecting lithology such as spontaneous potential and spontaneous gamma, curves reflecting physical properties such as sonic transit time, density and neutron logging curves, and curves reflecting oil-bearing properties such as resistivity.
[0055] Well logging interpretation results: Lithological or oil-bearing results interpreted based on well logging curves.
[0056] Geological stratification: This refers to the geological stratification commonly used in this area for exploration and development of the target layer.
[0057] Lithology: Lithology established by logging or core samples.
[0058] S5. Place the single-well column chart of the depth domain horizontally on the depth coordinate axis of the VSP corridor overlay profile, so that it is completely consistent with the depth of the VSP corridor overlay depth domain profile. The VSP corridor overlay depth domain profile is then loaded with logging curves, logging interpretation results, lithology, geological stratification and other information.
[0059] S6. Calibration is performed using the VSP corridor stacking depth domain profile and the pre-stack depth offset seismic data, and then placed laterally on the VSP corridor stacking profile depth coordinate axis.
[0060] S7, Appendix Figure 1 This yields the precise correspondence between the pre-stack depth-biased time domain and depth domain seismic reflection phase axes and the drilling lithology, geological stratification, and velocity.
[0061] By overlaying the VSP corridor time and depth domain profiles and pre-stack depth migration seismic time and depth domain profiles, geological information (geological stratification, well logging curves, well logging interpretation results, lithology, physical properties, etc.) forms an "L" bridge connection, achieving accurate calibration of the pre-stack depth migration seismic time and depth domains.
[0062] This embodiment utilizes the high accuracy, high velocity determination accuracy, and high resolution of VSP logging during well seismic calibration. It considers a high-precision matching of logging curves, logging interpretation results, lithology, geological stratification, and time-depth dual-domain seismic data, which is of great significance for well seismic calibration in blocks with large burial depths, complex structures, and rapid changes in longitudinal and lateral velocities. A set of well seismic calibration ideas and analysis methods based on geology, logging, and time-depth dual-domain seismic dynamic calibration and adjustment is proposed and implemented in software. This enables geological, geophysical, and drilling guidance researchers to analyze target strata accurately and with a basis during geological research, geophysical interpretation, and drilling geological guidance. Simultaneously, the VSP corridor overlay profile itself contains depth information, providing good comparability with logging curves, logging interpretation results, and lithological information from actual drilling. Therefore, by using the VSP corridor overlay profile as a bridge, precise matching among geology, logging, and seismic data can be achieved, enabling accurate well-seismic calibration of reservoirs of different depths, lithologies, and thicknesses, thereby improving the accuracy of geological and seismic interpretation and drilling geological guidance processes.
[0063] Based on the above-described VSP logging seismic time-depth dual-domain calibration method, this specification also provides another embodiment, implementing a VSP logging seismic time-depth dual-domain calibration device. It includes a processor and a memory storing processor-executable instructions, which, when executed by the processor, implement the aforementioned method steps.
[0064] The apparatus described may include a system, software (application), module, component, server, etc., that uses the methods described in the embodiments of this specification, combined with necessary implementation hardware. Based on the same inventive concept, the apparatuses in one or more embodiments provided in this specification can all be based on the embodiments described below. Since the implementation schemes and methods for solving the problem are similar, the implementation of specific apparatuses in the embodiments of this specification can refer to the implementation of the foregoing methods, and repeated details will not be elaborated further. As used below, "units" or "modules" are combinations of software and / or hardware that can implement a predetermined function. Although the apparatuses described in the following embodiments are preferably implemented in software, hardware implementations, or combinations of software and hardware, are also possible and contemplated.
[0065] The methods or apparatus described in the above embodiments provided in this specification can implement business logic through a computer program and record it on a storage medium. The storage medium can be read and executed by a computer to achieve the effects of the solutions described in the embodiments of this specification.
[0066] It should be noted that the apparatus described above in this specification may include other implementations based on the description of the relevant method embodiments. Specific implementations can be found in the description of the relevant method embodiments, and will not be repeated here. The various embodiments in this specification are described in a progressive manner; similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for hardware + program and storage medium + program embodiments, since they are basically similar to the method embodiments, the description is simple, and relevant parts can be referred to the description of the method embodiments.
[0067] The systems, devices, and modules described in the above embodiments can be implemented by computer chips or physical entities, or by products with certain functions. A typical implementation device is a computer. Specifically, a computer can be, for example, a personal computer, a laptop computer, a tablet computer, etc.
[0068] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.
Claims
1. A seismic time-depth dual-domain calibration method based on VSP logging, characterized in that, Including the following steps: Time-domain VSP profiles were obtained by acquiring and processing VSP logging data. The time-domain VSP profile is converted to the depth-domain VSP profile using the high-precision layer velocity obtained from VSP logging. The VSP corridor stacked time domain profile and pre-stack depth offset time domain seismic were used for calibration to obtain the correspondence between the VSP time domain profile and the time domain seismic, and the pre-stack depth offset time domain seismic was placed to the right of the time coordinate axis of the VSPlog stacked profile. The VSP corridor stacked depth domain profile and pre-stack depth-biased depth domain seismic data were used for calibration to obtain the correspondence between the phase axis of the pre-stack depth-biased time domain and depth domain seismic reflection phases and geological information, and were placed laterally on the depth coordinate axis of the VSP corridor stacked profile. Based on software engineering output, a seismic time-depth dual-domain calibration map based on VSP logging includes time and depth axes.
2. The seismic time-depth dual-domain calibration method based on VSP logging according to claim 1, characterized in that, The process of obtaining a time-domain VSP profile through VSP logging acquisition and processing involves obtaining a VSP corridor overlay profile through VSP logging acquisition and processing, followed by cutting and overlaying to obtain the time-domain VSP profile. The specific steps include: Step 1: Static time shift and alignment of VSP uplink waves. The specific method is as follows: VSP two-way vertical time T = initial arrival time Tfb + uplink propagation time Tup, that is, the time of each channel plus the initial arrival time of the downlink wave, so that the uplink waves are aligned according to their two-way time from the ground surface to the interface. Step 2, corridor excision, is specifically performed by excising a section of corridor along the first arrival wave, preserving as much of the first reflected wave as possible, and removing multiple reflected waves and noise. Step 3, corridor overlay, is specifically performed by vertically overlaying and summing the cut corridors to obtain the time-domain VSPlog overlay profile. Step 4: Place the time-domain VSPlog overlay profile to the right of the VSP corridor overlay profile, aligning its vertical time axis with it.
3. The seismic time-depth dual-domain calibration method based on VSP logging according to claim 1, characterized in that, When converting a time-domain VSP profile to a depth-domain VSP profile using high-precision layer velocities obtained from VSP logging, the average velocity and layer velocity can be calculated from the VSP arrival time. The calculation formula is as follows: The formula for calculating the velocity of the VSP layer is as follows: Formula for calculating average speed: Where X is the vertical distance between the trigger point and the wellhead, i.e., the well-source distance; H is the formation depth; and T is the first arrival time. The time-domain VSP corridor overlay profile is converted to the depth-domain corridor overlay profile based on the average velocity.
4. The seismic time-depth dual-domain calibration method based on VSP logging according to claim 1, characterized in that, It also includes the step of creating a depth domain single-well column chart, wherein the depth domain single-well column chart includes one or more of the following: depth, logging curves, logging interpretation results, lithology, and geological stratification information.
5. The seismic time-depth dual-domain calibration method based on VSP logging according to claim 4, characterized in that, The logging curves can be curves reflecting lithology, such as spontaneous potential or spontaneous gamma curves, or curves reflecting physical properties, such as sonic transit time, density, neutron curves, or resistivity curves reflecting oil content.
6. The seismic time-depth dual-domain calibration method based on VSP logging according to claim 4, characterized in that, The well logging interpretation results are lithological or oil-bearing results interpreted based on the well logging curves.
7. The seismic time-depth dual-domain calibration method based on VSP logging according to claim 4, characterized in that, The geological stratification described is the geological stratification commonly used in this area for exploration and development of the target layer, and can be accurate to the sub-layer.
8. The seismic time-depth dual-domain calibration method based on VSP logging according to claim 4, characterized in that, The lithology referred to is the lithology established by logging or core samples.
9. The seismic time-depth dual-domain calibration method based on VSP logging according to claim 1, characterized in that, The depth domain single-well column chart is placed horizontally on the depth coordinate axis of the VSP corridor overlay profile, and its depth is completely consistent with that of the VSP corridor overlay depth domain profile. The VSP corridor overlay depth domain profile is loaded with one or more of the following: well logging curves, well logging interpretation results, lithology, and geological stratification information.
10. A seismic time-depth dual-domain calibration device based on VSP logging, characterized in that, It includes at least one processor and a memory storing computer-executable instructions, and implements the steps of any of the methods described in claims 1 to 9.