A method for comprehensive fine description of sandstone and conglomerate body by well logging and seismic
By combining geological, logging, and seismic methods, the depositional stages and spatial distribution of sandstone and conglomerate bodies are precisely characterized, solving the existing problems in the exploration and development of sandstone and conglomerate bodies and achieving high-precision characterization of the internal structure of sandstone and conglomerate bodies and accurate location of favorable reservoirs.
Patent Information
- Application Number
- CN202110188258.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-02-18
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2041-02-18
Smart Images
Figure CN114966846B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of oil exploration, and particularly relates to a method for comprehensively and finely depicting a sandy conglomerate body by using well and seismic data. BACKGROUND
[0002] As an important type of subtle oil and gas reservoirs, sandy conglomerate reservoirs are widely distributed in the world. Typical sandy conglomerate reservoirs in China include the Yingcheng and Shahezi formations in the Xujiaweizi area of the Songliao Basin, the Shahejie Formation in the Jiyang Depression of the Bohai Bay Basin, the Permian in the Kebai area of the Junggar Basin, the Lulehe Formation in the Kunbei area of the Qaidam Basin, the Upper Triassic and Lower Jurassic in the northwest of Sichuan Province, and the like. These sandy conglomerate reservoirs are mainly distributed in steep slope zones of faulted basins with large ancient topographic relief, steep slopes and frequent tectonic activities, and are often distributed in a proximal source, rapidly accumulated and multi-period superimposed manner, and are in a finger-like contact with lacustrine mudstone, with obvious spatial distribution difference, fast lithofacies change, low rock maturity, strong reservoir heterogeneity and great difficulty in exploration and development.
[0003] For the exploration and development of sandy conglomerate reservoirs, the fine depiction of the internal periods of thick sandy conglomerate is the primary key and also a technical difficulty. Since there are no fossils in thick sandy conglomerate sediments, the cycle characteristics of logging curves are not obvious, and in addition, the resolution of seismic data is poor, so the traditional method for dividing the sandy conglomerate deposition periods has strong subjectivity. At present, scholars have carried out some research work on the sedimentary cycles and reservoir configurations of sandy conglomerate bodies, and tried to finely depict the sandy conglomerate bodies. On the one hand, scholars try to extract useful information of the sedimentary cycle interface by processing, reconstructing and transforming logging data, such as using wavelet transform of logging signals to restore three and four level base level curves, and carrying out interwell isochronous stratigraphic correlation; based on the Miller cycle analysis, db4 wavelet transform, time-frequency analysis technology and Fisher graphic method are comprehensively used to divide thick sandy conglomerate bodies into several long-term, medium-term and short-term sedimentary cycles.
[0004] On the other hand, scholars try to use three-dimensional seismic data to divide the internal periods and sequences of sandy conglomerate bodies, such as using 3D seismic data sequence stratigraphic interpretation method, frequency division processing method, seismic horizontal time slice method, etc. to study the spatial distribution characteristics and migration evolution law of sandy conglomerate fan bodies.
[0005] Seismic petrology method developed gradually in recent years is also a research hotspot in this field, but at present, most of them are microscopic seismic petrophysical research, mainly studying the seismic elastic parameter characteristics of the reservoir, and the macroscopic seismic petrology research matched with seismic sedimentology is still insufficient, that is, the method for studying the relationship between lithofacies and lithological combination and seismic reflection characteristics is lacking, which also causes strong multi-solution of seismic attributes in lithology analysis.
[0006] The current seismic petrology research mainly obtains the statistical rules between the lithology, physical property parameters and seismic elastic parameters obtained by analyzing logging data, and then carries out seismic reservoir prediction, and the well-seismic statistical combination is relatively less, and lacks stratigraphic genetic guidance and analysis. In addition, for the period division of sand and gravel reservoir, the internationally recognized SEG / EAGA model and Marmousi model for studying complex geological bodies such as salt dome and nappe structure also have important reference significance for the period division of sand and gravel reservoir.
[0007] In summary, the fine research on the sedimentary period of sand and gravel body has made certain progress, but in the research process, more single methods are used for description, and the combination degree of geology, logging and seismic is not enough. It is necessary to find the combination point and make it play its own advantages to better serve the fine description of sand and gravel. However, there is no related research and report at present. SUMMARY
[0008] The main purpose of the present application is to provide a sand and gravel body well-seismic comprehensive fine description method, which combines the geological, logging and seismic fine description methods, finds the effective combination point, and applies the combined system method to the sand and gravel reservoir to verify the application, and establishes an effective sand and gravel body well-seismic comprehensive fine description method.
[0009] To achieve the above purpose, the technical scheme adopted by the present application is as follows:
[0010] The present application provides a sand and gravel body well-seismic comprehensive fine description method, which comprises the following steps: combining the reservoir configuration division method, fine description of the vertical sedimentary structure level of sand and gravel; using the seismic sedimentology analysis method, well-seismic comprehensive description of the spatial distribution of sand and gravel body, and clear spatial characteristics of reservoir configuration unit in target area; establishing the parameter knowledge base of internal structure unit of sand and gravel body, and predicting the development position of favorable reservoir in target area.
[0011] Further, the fine description method of sand and gravel vertical sedimentary structure level comprises:
[0012] 1) Using field outcrop model combined with three-dimensional seismic, referring to regional sedimentary background and sedimentary model, establishing 1-2 grade sedimentary cycle framework;
[0013] 2) According to the hierarchical constraint in the method of reservoir configuration division and the method of pattern fitting, 3-4 grade sedimentary cycles are divided by using logging and seismic response, wherein the 4 grade cycle is equivalent to single sand body grade;
[0014] 3) 5-6 grade sedimentary cycles are divided by using core and imaging logging mutual calibration, wherein the 5 grade cycle is equivalent to single stage braided water channel, and the thickness of the braided water channel sand gravel body is determined according to the single stage braided water channel, and the 6 grade cycle is equivalent to single stage accretion body in the braided water channel.
[0015] Further, on the basis of well-seismic comprehensive fine division of the sand gravel body vertical cycle, the three-dimensional seismic data are processed by introducing the method of seismic sedimentology, and then the spatial distribution of the sand gravel is described.
[0016] Further, the specific method comprises:
[0017] S1. Seismic tracking and interpretation are carried out on the 4-5 grade cycle interface in the sand gravel body, on the basis of the traditional wave peak and wave trough tracking, the wave peak envelope tracking method is used to delineate the overall distribution range of the 4-5 grade sedimentary stage;
[0018] S2. The attribute slice extraction of the sand gravel sensitive attribute is carried out by using the 90 degree phase conversion, horizontal slice method, combined with the amplitude-preserving imaging and coherent processing method;
[0019] S3. The attribute boundary sensitive parameter variance, arc length and root mean square amplitude are optimized, the boundary of the single stage sand gravel body is described, and the logging data are used for auxiliary verification, and the length, width, shape and extension range of the single stage underwater fan braided water channel sand gravel body are determined.
[0020] S4. The researches of predecessors on the sedimentary environment, palaeogeomorphology, boundary fault activity and lake level change are investigated, and the quantitative relationship between the sand gravel body parameters is determined by using the multiple regression analysis method.
[0021] Further, the spatial distribution of the sand gravel body is described based on the seismic sedimentology analysis technology well-seismic comprehensive description, and the characteristic parameters of the sand gravel body are determined, including the thickness, length, width, extension direction and distribution range, and the distribution of the favorable reservoir is quantitatively predicted.
[0022] Further, the method for predicting the development position of the favorable reservoir in the target area is as follows: the sand gravel body with large thickness, length, width, stable shape and wide extension range is verified by drilling, and the development position of the favorable reservoir is determined by combining the sand body reservoir physical property.
[0023] Compared with the prior art, the present application has the following advantages:
[0024] Reservoir architecture research has made great progress in fluvial facies, but due to the complexity of the genetic characteristics of the sandstone conglomerate body, especially the underwater fan sandstone conglomerate body, the spatial development and distribution of the sandstone conglomerate body are non-uniform, and the internal structure of the sandstone conglomerate body is difficult to depict, and currently there are few research literatures reported. The application introduces the analysis idea of reservoir architecture, organically fuses the geological, logging and seismic fine depiction methods into the division of each level architecture, divides the 1-2 level cycle by combining the field outcrop model with the three-dimensional seismic, divides the 3-4 level cycle by using the logging and seismic response, divides the 5-6 level cycle by using the core and imaging logging mutual calibration, and each level cycle corresponds to a level architecture. From the cycle genesis and the relationship with exploration and development, the 4-5 level architecture of the sandstone conglomerate reservoir is most closely related to the oil and gas exploration and development. The division scheme and the research technology have important significance for the fine exploration and development of the underwater fan sandstone conglomerate reservoir, and have certain popularization value for the research of the same type of reservoir.
[0025] For the spatial distribution research of the sandstone conglomerate body, the traditional method is seismic attribute analysis or lithology inversion, and the research accuracy is often low, and it is difficult to depict the distribution of the 5-6 level architecture units in the sandstone conglomerate body. The application introduces the research technology of seismic sedimentology, forms a set of systematic seismic analysis method, maximizes the advantages of seismic data, and effectively overcomes the problems of complex internal structure of the sandstone conglomerate body and unclear marks. Through the envelope tracking of the same phase axis of the architecture interface, seismic body processing, phase conversion, edge carving and other technologies, the distribution pattern of the 4-5 level architecture units in the sandstone conglomerate body is finely depicted, the parameter knowledge base of the internal structure units of the sandstone conglomerate body is established, and a set of well-seismic combined fine depiction method of the sandstone conglomerate body is formed.
[0026] After verification, the method has high accuracy. BRIEF DESCRIPTION OF DRAWINGS
[0027] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and, together with their description, serve to explain the application.
[0028] Figure 1 The flow chart of the well-seismic combined fine depiction method of the sandstone conglomerate body is described for a specific embodiment of the application. DETAILED DESCRIPTION
[0029] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
[0030] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.
[0031] In order for those skilled in the art to more clearly understand the technical solutions of the present application, the technical solutions of the present application will be described in detail below in conjunction with specific examples.
[0032] Embodiments
[0033] As shown in the following table, the sandstone and conglomerate well-seismic comprehensive fine description method includes the following steps: Figure 1
[0034] Step 1. Fine description of sandstone and conglomerate vertical sedimentary structure level in combination with reservoir configuration division method:
[0035] 1) Using field outcrop model in combination with three-dimensional seismic, referring to regional sedimentary background and sedimentary mode, establishing 1-2 grade sedimentary cycle framework;
[0036] 2) According to level constraint and mode fitting method in the reservoir configuration division method, using logging and seismic response to divide 3-4 grade sedimentary cycles, wherein the 4 grade cycle is equivalent to single sand body level;
[0037] 3) Using core and imaging logging mutual calibration to divide 5-6 grade sedimentary cycles, wherein the 5 grade cycle is equivalent to single stage braided channel, and according to this, the thickness of the braided channel sandstone and conglomerate is determined, and the 6 grade cycle is equivalent to single stage accretion body in the braided channel.
[0038] Step 2. Using seismic sedimentology analysis method, well-seismic comprehensive description of spatial distribution of sandstone and conglomerate, and clear spatial characteristics of reservoir configuration unit in target area, the specific method including the following steps:
[0039] S1. Seismic tracking and interpretation of 4-5 grade cycle interfaces inside the sandstone and conglomerate, on the basis of traditional wave peak and trough tracking, using wave peak envelope tracking method to delineate the overall distribution range of 4-5 grade sedimentary stages;
[0040] S2. Using 90° phase conversion, horizontal slice method, in combination with amplitude-preserving imaging and coherent processing method, attribute slice extraction is performed on sandstone and conglomerate sensitive attributes;
[0041] S3. Preferential attribute boundary sensitive parameter variance, arc length, root mean square amplitude, boundary of single period glutenite body is depicted, and logging data is used for auxiliary verification, length, width, shape, extension range of single period underwater fan braid channel glutenite body are determined.
[0042] S4. Research on previous researches on sedimentary environment, palaeogeomorphology, boundary fault activity, lake level change, etc. is conducted, and multiple regression analysis method is used to determine quantitative relationship between parameters of glutenite body based on the researches.
[0043] Step 3. Parameter knowledge base of internal structure unit of glutenite body is established, and development position of favorable reservoir in target area is predicted: spatial distribution of glutenite body is depicted by well-seismic comprehensive analysis based on seismic sedimentology, characteristic parameters of glutenite body are determined, including thickness, length, width, extension direction, distribution range, distribution of favorable reservoir is quantitatively predicted, and parameter knowledge base of internal structure unit of glutenite body is established.
[0044] Method for predicting development position of favorable reservoir in target area: drilling verification is conducted on glutenite body with thick thickness, long length, wide width, stable shape and wide extension range, and development position of favorable reservoir is determined in combination with sand body reservoir physical property.
[0045] The method is used in Yongan area of Shengli oilfield, and Yong928 Inclination 1, Yong928 Inclination 2, Yong928 Inclination 3, Yong928 Inclination 4, Yong928 Inclination 5, Yong936 Inclination 1, Yong936 Inclination 2, Yong936 Inclination 3, a total of eight evaluation wells are deployed in the area, good glutenite reservoirs are drilled in the purpose layer of the wells, and the accuracy of the method is fully verified.
[0046] The above embodiment is a preferred embodiment of the present application, but the embodiment of the present application is not limited by the above embodiment, any change, modification, substitution, combination, simplification made without departing from the spirit and principle of the present application should be equivalent replacement, and all are included in the protection scope of the present application.
Claims
1. A method for comprehensive fine characterization of sand-shale reservoirs by combining seismic and well data, characterized in that, The method comprises the following steps: In combination with the reservoir configuration division method, the vertical sedimentary structure hierarchy of the glutenite is finely described; the spatial distribution of the glutenite body is finely described by using the seismic sedimentology analysis method and the well-seismic combination, and the spatial features of the reservoir configuration unit in the target area are determined; the parameter knowledge base of the internal structure unit of the glutenite body is established, and the favorable reservoir development position in the target area is predicted; On the basis of the well-seismic combination and the fine division of the vertical cycle of the glutenite body, the spatial distribution of the glutenite is described by introducing the seismic sedimentology method and processing the three-dimensional seismic data; The specific method comprises: S1. The 4-5 grade cycle interfaces in the internal structure of the glutenite body are tracked and interpreted by using the wave peak envelope tracking method on the basis of the traditional wave peak and trough tracking, and the overall distribution range of the 4-5 grade sedimentary period is circled; S2. The attribute slice extraction of the glutenite sensitive attribute is performed by using the 90° phase conversion, the horizontal slice method, the amplitude-preserving imaging and the coherent processing method; S3. The boundary of the single-stage glutenite body is described by selecting the attribute boundary sensitive parameter variance, arc length and root mean square amplitude, and the length, width, shape and extension range of the single-stage underwater fan braided channel glutenite body are determined by using the logging data for auxiliary verification; S4. The quantitative relationship between the parameters of the glutenite body is determined by using the multivariate regression analysis method based on the researches of the previous people on the sedimentary environment, the paleogeomorphology, the boundary fault activity and the lake level change.
2. The method of claim 1, wherein, The fine description method of the vertical sedimentary structure hierarchy of the glutenite comprises: 1) The 1-2 grade sedimentary cycle framework is established by using the field outcrop model in combination with the three-dimensional seismic, referring to the regional sedimentary background and the sedimentary mode; 2) The 3-4 grade sedimentary cycle is divided by using the logging and the seismic response according to the hierarchy constraint and the mode fitting method in the reservoir configuration division method, wherein the 4 grade cycle is equivalent to the single sand body level; 3) The 5-6 grade sedimentary cycle is divided by using the core and the imaging logging, wherein the 5 grade cycle is equivalent to the single-stage braided channel, and the thickness of the braided channel glutenite body is determined accordingly, and the 6 grade cycle is equivalent to the single-stage accretion body in the braided channel.
3. The method of claim 1, wherein, The method for predicting the favorable reservoir development position in the target area: the glutenite body with the large thickness, the large length and width, the stable shape and the wide extension range is verified by drilling, and the favorable reservoir development position is determined in combination with the glutenite reservoir property.