CN116184525A

CN116184525A - Stratum trellis lower sea land transition phase shale three-dimensional lithofacies modeling method

Info

Publication number: CN116184525A
Application number: CN202210908910.4A
Authority: CN
Inventors: 赵晓明; 张喜; 梁岳立; 李树新
Original assignee: Southwest Petroleum University
Current assignee: Southwest Petroleum University
Priority date: 2022-07-29
Filing date: 2022-07-29
Publication date: 2023-05-30

Abstract

The invention discloses a method for modeling a shale three-dimensional lithofacies of a stratum lattice lower sea-land transition phase, which comprises the steps of collecting seismic data and evaluation well data of a research area, and determining a modeling boundary of shale reservoir three-dimensional geological modeling according to the seismic data and the evaluation well data of the research area; establishing a seismic fine interpretation horizon bottom layer model according to the seismic data of a research area, evaluation well data and a determined modeling boundary of shale reservoir three-dimensional geological modeling, establishing a top and bottom layer model under the constraint of the bottom layer model, and setting vertical grids according to the average stratum thickness and lithology thickness of each horizon under the five-level horizon layer model; and respectively establishing a lithofacies model corresponding to the lithofacies type according to the lithofacies type of the research area and the distribution of the lithofacies under the five-level horizon layer model, wherein each lithofacies model forms the lithofacies model of the research area.

Description

Stratum trellis lower sea land transition phase shale three-dimensional lithofacies modeling method

Technical Field

The invention relates to the field of geology, in particular to a method for modeling a stratum grillage lower sea land transition phase shale three-dimensional lithofacies.

Background

The characteristics of thin sea-land transition phase shale production layer, extremely strong non-uniformity and the like generate a plurality of difficulties for large-scale and benefit development of shale gas, so that clearer understanding of the non-uniformity of the sea-land transition phase shale can improve the efficiency for exploration and development of the shale gas reservoir. The establishment of the three-dimensional geological model is used for quantitatively characterizing the heterogeneity of the shale reservoir in the sea-land transition phase, and has important significance for the exploration and development of the oil and gas reservoirs.

At present, the three-dimensional geologic modeling research on shale gas reservoirs is less, and the east edge mountain western group mountain of the Erdos basin is provided ₂ ³ The research on modeling of the inferior Duan Hailiu transitional phase high-quality shale is not yet reported. The reason of the shale gas is mainly two aspects, firstly, the shale research in China is mostly biased to the development stage, and the research of shale gas by most scholars is mainly concentrated on engineering aspects such as large-scale fracturing acidification, acquisition efficiency and the like, but the knowledge is not accurate in geology; secondly, the sea-land transition phase shale of China is still in an early exploration stage at present, and the research developed for the sea-land transition phase shale layer of the east-edge Shanxi group of the Erdos basin mainly comprises a deposition environment, reservoir characteristics, hydrocarbon source rock types and the like.

Aiming at the characteristics of thin sea-land transition phase shale production layer, extremely strong heterogeneity and the like, the construction of a fine three-dimensional geological model is a key point for understanding the three-dimensional spatial distribution of the gas reservoir. The reservoir three-dimensional geological modeling mainly comprises a structural model, a lithofacies model and an attribute model, and the research mainly comprises construction of the structural model, the lithofacies model and the attribute model based on a high-precision stratum trellis. Through the construction of the fine structural model and the lithofacies model, the method has certain reference significance for reservoir evaluation, well position optimization and horizontal well track guiding design, and provides scientific basis for oil and gas field development. Conventional three-dimensional geologic modeling techniques have been less suitable for shale reservoirs, particularly mountains ₂ ³ The high-quality shale layer section at the bottom of the sub-section is thinner, and the seismic data are difficult to identify.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for modeling a three-dimensional lithofacies of a sea-land transition phase shale under a stratigraphic framework, which is characterized by comprising the following steps:

step one, acquiring seismic data and evaluation well data of a research area, and determining a modeling boundary of shale reservoir three-dimensional geological modeling according to the seismic data and the evaluation well data of the research area;

establishing a bottom layer model of a seismic fine interpretation horizon according to seismic data of a research area, evaluation well data and a modeling boundary of a determined shale reservoir three-dimensional geological modeling, establishing a top and bottom layer model under the constraint of the bottom layer model, establishing four-level horizon layer models of PSQ1, PSQ2, PSQ3 and PSQ4 of the modeling horizon of the top and bottom layer model from bottom to top, establishing five-level horizon layer models of FSQ1-FSQ11 according to the four-level horizon layer models, and setting vertical grids according to the average stratum thickness and lithology thickness of each horizon under the five-level horizon layer models;

and thirdly, respectively establishing a lithofacies model corresponding to the lithofacies type according to the lithofacies type of the research area and the distribution of the lithofacies under the five-level horizon layer model, wherein each lithofacies model forms the lithofacies model of the research area.

2. The method for modeling the three-dimensional lithofacies of the transition phase shale of the lower sea and land of the stratigraphic framework according to claim 1, wherein the steps of collecting the seismic data and evaluating the well data of the research area comprise the following steps: acquiring well position coordinates and well track data of an evaluation well in a research area; fine logging interpretation data of the evaluation well of the research area; the well stratification data, including four-level and five-level sequence and top and bottom formation maps of the investigation region, are evaluated.

3. The method for modeling the three-dimensional lithofacies of the shale of the lower sea-land transition phase of the stratigraphic framework according to claim 2, wherein the modeling boundary of the shale reservoir three-dimensional geologic modeling is determined according to the seismic data of a research area and the evaluation well data, and the modeling boundary is a three-dimensional seismic data range.

4. A method of three-dimensional lithofacies modeling of a stratigraphic framework lower sea-land transition phase shale according to claim 3, wherein said establishing a seismic fine interpretation horizon bottom level model based on the seismic data of the investigation region, the evaluation well data and the determined modeling boundaries of the shale reservoir three-dimensional geologic modeling, establishing a top-bottom level model under the constraints of the bottom level model, comprises: and establishing a top-bottom layer model under the constraint of the bottom layer model by combining the logging layering data based on the seismic interpretation data.

5. The method for modeling a three-dimensional lithofacies of a stratigraphic framework lower sea-land transition phase shale of claim 4, wherein the top-bottom horizon modeling horizon is a four-level horizon model of PSQ1, PSQ2, PSQ3 and PSQ4 from bottom to top, and the method for modeling a five-level horizon model of FSQ1-FSQ11 according to the four-level horizon model comprises: the four-level layers of PSQ1, PSQ2, PSQ3 and PSQ4 are divided into 11 five-level layers of FSQ1-FSQ11 and the like from bottom to top, and an FSQ1-FSQ11 five-level layer model is built according to the four-level layer model.

6. The method for modeling the three-dimensional lithofacies of the transition phase shale of the lower sea and land of the stratigraphic framework according to claim 1, wherein the vertical grids are arranged according to the average stratigraphic thickness and lithology thickness of each horizon under the five-level horizon layer model, and the vertical grids are as follows: the thinnest lithologic thickness of each stratum can be characterized, and the vertical grids are arranged in a proportional dividing mode.

7. The method for modeling the three-dimensional lithofacies of the transition phase shale of the lower sea and land of the stratigraphic framework according to claim 1, wherein the method for respectively establishing the lithofacies model of the corresponding lithofacies type according to the lithofacies type of the research area and the lithofacies distribution under the five-level sequence comprises the following steps: and adopting cluster analysis seismic attribute fusion, carrying out Pearson correlation analysis based on Bayesian statistical theory, calculating the correlation between the attribute of the lithofacies and each seismic attribute to obtain a correlation coefficient R, selecting the seismic attribute with the correlation coefficient within a set threshold range according to the magnitude of the correlation coefficient, establishing a measurement relation between the lithofacies and the seismic attribute, calculating a plane phase diagram of the lithofacies to obtain the spreading characteristic of the lithofacies, and establishing a lithofacies model.

The beneficial effects of the invention are as follows: the technical proposal provided by the invention can realize the hierarchical and multi-stage mountain depiction by using the high-precision stratum grillwork, taking the logging interpretation data as hard data and the three-dimensional seismic data as soft data ₂ ³ Duan Hailiu transition phase shale three-dimensional space spread.

Drawings

FIG. 1 is a schematic diagram of a three-dimensional lithofacies modeling method of a stratum lattice lower sea-land transition phase shale;

FIG. 2 is a three-dimensional lithofacies modeling flow diagram intent;

FIG. 3 study area mountain ₂ ³ A relation diagram of a fitting result of the subsection seismic attribute multivariate model and a logging interpretation result;

FIG. 4 study area mountain ₂ ³ Schematic diagram of a sub-section shale model;

FIG. 5 is a mountain of a study area ₂ ³ A subsection FSQ3 coal seam plane phase diagram;

FIG. 6 is a schematic diagram of a top limestone model of a research area Taiyuan group;

FIG. 7 is a mountain of a study area ₂ ³ Sub-section FSQ1 powder sand shale plane phase diagram

FIG. 8 is a mountain of a study area ₂ ³ A sub-segment FSQ1 carbonaceous shale plane phase diagram;

FIG. 9 is a mountain of a study area ₂ ³ Duan Yanxiang model grating.

Detailed Description

The technical solution of the present invention will be described in further detail with reference to the accompanying drawings, but the scope of the present invention is not limited to the following description.

For the purpose of making the technical solution and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the particular embodiments described herein are illustrative only and are not intended to limit the invention, i.e., the embodiments described are merely some, but not all, of the embodiments of the invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by a person skilled in the art without making any inventive effort, are intended to be within the scope of the present invention. It is noted that relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

The features and capabilities of the present invention are described in further detail below in connection with the examples.

As shown in fig. 1, a method for modeling a stratum lattice undersea land transitional phase shale three-dimensional lithofacies comprises the following steps:

Further, the collecting the seismic data and evaluating the well data of the research area includes: acquiring well position coordinates and well track data of an evaluation well in a research area; fine logging interpretation data of the evaluation well of the research area; the well stratification data, including four-level and five-level sequence and top and bottom formation maps of the investigation region, are evaluated.

Further, the modeling boundary of the shale reservoir three-dimensional geologic modeling is determined according to the seismic data of the research area and the evaluation well data, wherein the modeling boundary is a three-dimensional seismic data range.

Further, the building of the seismic fine interpretation horizon bottom layer model according to the seismic data of the research area, the evaluation well data and the determined modeling boundary of the shale reservoir three-dimensional geological modeling, the building of the top and bottom layer model under the constraint of the bottom layer model comprises the following steps: and establishing a top-bottom layer model under the constraint of the bottom layer model by combining the logging layering data based on the seismic interpretation data.

Further, the modeling horizon of the top-bottom layer model is a four-level horizon layer model of PSQ1, PSQ2, PSQ3 and PSQ4 from bottom to top, and establishes five-level horizon layer models of FSQ1-FSQ11 according to the four-level horizon layer model, comprising: the four-level layers of PSQ1, PSQ2, PSQ3 and PSQ4 are divided into 11 five-level layers of FSQ1-FSQ11 and the like from bottom to top, and an FSQ1-FSQ11 five-level layer model is built according to the four-level layer model.

Further, the vertical grid is set according to the average stratum thickness and lithology thickness of each horizon under the five-level horizon layer model, wherein the vertical grid is as follows: the thinnest lithologic thickness of each stratum can be characterized, and the vertical grids are arranged in a proportional dividing mode.

Further, according to the lithofacies type of the research area and the lithofacies distribution under the five-level sequence, respectively establishing a lithofacies model corresponding to the lithofacies type, including: and adopting cluster analysis seismic attribute fusion, carrying out Pearson correlation analysis based on Bayesian statistical theory, calculating the correlation between the attribute of the lithofacies and each seismic attribute to obtain a correlation coefficient R, selecting the seismic attribute with the correlation coefficient within a set threshold range according to the magnitude of the correlation coefficient, establishing a measurement relation between the lithofacies and the seismic attribute, calculating a plane phase diagram of the lithofacies to obtain the spreading characteristic of the lithofacies, and establishing a lithofacies model.

Specifically, 6 evaluation wells are arranged in the research area, and data such as earthquake, logging and the like required by modeling are collected and arranged according to the requirement of modeling software Petrel on data formats. The data of the research area are arranged, and the method mainly comprises the following work:

1) Arranging well position coordinates and well track data of 6 evaluation wells in a research area;

2) Finishing fine logging interpretation data of 6 evaluation wells in a research area;

3) Sorting layered data of 6 evaluation wells, wherein the layered data comprise a four-level layer sequence and a five-level layer sequence;

4) Mountain western group mountain of arrangement research area ₂ ³ And constructing a drawing of the top surface and the bottom surface of the subsection.

Determining the modeling boundary of the shale reservoir three-dimensional geologic modeling according to the existing seismic data and well data of the A well region and the researched content, wherein the modeling area is about 100km ² . The modeling layer is composed of four-level layer sequences such as PSQ1, PSQ2, PSQ3, PSQ4 and the like and 11 five-level layer sequences such as FSQ1-FSQ11 and the like from bottom to top, and the distribution of the limestone in the east kiln at the top of the Taiyuan group in the research area is stable, so that the bottom of the model is designed to be the limestone at the top of the Taiyuan group. The fine grid simulation can more accurately represent geological units with smaller target layers in a research area, and although the smaller grid size means the finer model, the design is carried out according to actual conditions, otherwise, the operation time of the model is prolonged, so that the efficiency is reduced. The modeling grid of the study is designed as follows: the planar grid pitch was 25m×25m, the longitudinal grid precision was 0.7m, and the number of grids amounted to 2200 tens of thousands. Since the object source direction of the research area is from north to south, the grid direction is the true north direction.

The three-dimensional structure model can be established to better represent the spatial distribution relation of the characteristics such as the distribution of the thickness of the stratum in the longitudinal and transverse directions, the trend of the stratum, the development of faults and the like. The structural model mainly comprises two parts, namely a layer model and a fault model, but the fault development of a research area is less and is not affected by faults, so that only layer modeling is carried out. In the process of layer modeling, a structural surface for fine interpretation of seismic data is taken asConstraint, building mountain through well-seismic combination ₂ ³ The construction surface of each minor layer of the subsection. So in the modeling process, the seismic fine interpretation horizon mountain is firstly established ₂ ³ Sub-section bottom layer model, then build mountain under its constraint ₂ ³ Sub-segment top-bottom layer models, PSQ1, PSQ2, PSQ3, PSQ4 and other four layer models, further constructing FSQ1-FSQ11 and other 11 layer models, and building a bridge for the subsequent lithology model. The structural surface not only can accurately reflect the accuracy of the stratum depth of each well position, but also can visually show the change of the structural trend among the wells of the research area and the structural characteristics of each small layer. According to the established construction model, the A well region is high in the south east and low in the north west in the whole construction model, and a part of the A well region has a slight construction.

The vertical grid arrangement is scaled. In order to ensure that the vertical thinner lithology performance is characterized, the size of the vertical grid is set to be 0.7m in the study, and the vertical grids of each layer are set as follows according to the average stratum thickness and lithology thickness of each layer under the five-level sequence: the number of FSQ1 layers is 9, the number of FSQ2 layers is 13, the number of FSQ3 layers is 15, the number of FSQ4 layers is 7, the number of FSQ5 layers is 10, the number of FSQ6 layers is 13, the number of FSQ7 layers is 10, the number of FSQ8 layers is 7, the number of FSQ9 layers is 8, the number of FSQ10 layers is 8, the number of FSQ11 layers is 10, and the vertical grid is set to be 1 (table 5-1) because only one lithology of limestone is involved at the top of the Taiyuan group.

TABLE 5-1A well Shanxi mountain group mountain ₂ ³ Number of vertical grids of each small layer of sub-section

The same isochronous modeling layer may have a multi-level structure, so that modeling should be performed hierarchically, i.e. a large order of target distribution is first established, then a hierarchical control is performed, and a smaller order of target distribution model is sequentially established. The basic idea is as follows: under the high-precision stratum trellis, the lithofacies of different grades are spread and characterized, and the lithofacies of each small layer of the research area is modeled step by using a deterministic modeling method (assignment method), as shown in figure 2.

Mountain-western group mountain according to subject research result ₂ ³ The subsections identify 5 typical lithofacies types, which are silty shale, carbonaceous shale, gray black shale, coal and sand facies, respectively. The top of the Taiyuan group is provided with east dakiln limestone with stable distribution.

Lithofacies division:

1. coast sand lithology

The lithofacies are fine sandstone and silt, the whole rock is gray, the sorting property is general, the grinding roundness is good, the lithofacies are in a secondary state, the sorting property is moderate, and the clay is cemented. The composition is mainly quartz, the content is about 80%, the composition contains a certain amount of feldspar and a small amount of other rock fragments, the feldspar accounts for about 15%, the fragments and other minerals are about 5%, and the development calcite is filled in cracks.

2. Coal seam

The coal bed is black, has higher carbonization degree, is crisp, can pollute hands, and is cleaved to develop, and the cleaved surface is rich in gloss. The coal bed is formed by plant scraps and peat.

3. Carbonate rock

The lithofacies are limestone, the whole rock is gray black, the sorting property is general, the grinding roundness is good, and the compactness is strong. The calcite accounts for 48.2-52.1%, the dolomite accounts for 21.4-23.0%, the argillaceous and other insoluble substances account for 26.5-29.2%, and the calcite is filled in the cracks.

4. Gray black shale phase

The different colors of sedimentary rock represent the formation under different sedimentary environments, and the color depth indicates the more and less organic matters of the rock. The shale phase is gray black-black, does not pollute hands, develops relatively in page, and is filled with a partially-seen calcite film. The main mineral in the microcosmic is clay mineral with the content of about 60 percent, and the surface of the clay mineral is attached by dark organic matters. The mineral component is quartz, and the content is about 40%. The black shale has high organic matter content, and the maximum value reaches 11.21%. And autogenous minerals such as siderite, pyrite and the like can be seen, and deeper water bodies in a strong reduction environment are reflected.

5. Silty shale phase

The lithofacies are mainly silty shale, the color is gray-dark gray, the clay structure is hard, and the silty shale is unevenly distributed. The fossil distribution of carbonized plant residual stems can be seen at the section. The main mineral components include clay mineral, sandy crumb and very little pyrite. The clay mineral content is more than 60% -70%. The content of sandy scraps accounts for 30% -40% of that of quartz. Pyrite content is rare, TOC content is between 2% -3%.

6. Carbonaceous shale phase

The lithofacies are wholly gray black-black, pure in quality, low in carbonization degree and slightly dirty in hands, gray black carbonaceous shale is frequently simultaneously appeared with a coal bed, and a coal seam is partially seen, so that the coal bed is transited from lower carbonaceous shale to upper coal bed. Common carbonaceous plant fossils.

5.2.1 sandstone lithofacies model

The lithology model is built, firstly, the three-dimensional seismic data body can be used for identifying and analyzing the space change characteristics of lithology on a plane, and the high-precision three-dimensional seismic data can be used for identifying lithology boundary characteristics, so that the lithology model is one of main constraint conditions in the lithology modeling process.

In the modeling process, however, firstly, correlation between the seismic data volume and lithology needs to be analyzed, and if more obvious correlation exists, the data can be used as constraint conditions for lithology modeling. In analyzing the relationship between a seismic data volume and lithology, it is necessary to measure the statistical characteristics of the seismic data to reflect the subsurface geologic information. Therefore, the distribution characteristics of lithology in the three-dimensional space can be better judged by extracting the related seismic attributes. The seismic attributes are classified into 8 major categories 91 such as amplitude, waveform, frequency and the like according to the characteristics of seismic waves and reservoir characteristics, and the most common is Quincy Chen et al (1997). Among them, the three properties of amplitude, frequency and phase are the most basic properties (Zhang Kebao, 2007), and the amplitude-class related properties are more closely related to lithology information. The amplitude-class related seismic attributes mainly include root mean square amplitude, average amplitude, maximum amplitude, minimum amplitude, arc length, etc. Through the optimization of various attributes, the root mean square amplitude attribute is selected for judgment and division of each lithology in the study. The research area has 4 lithologies such as sandstone, coal seam, limestone and shale, and firstly, the sandstone is taken as an example, and the distribution characteristics of the sand body of the research area are depicted through seismic attributes.

1. Single attribute analysis

First, mountain is extracted by Petrel software ₂ ³ And (3) carrying out root mean square amplitude calculation on each seismic attribute of the sub-section, and then counting the root mean square amplitude value of each well passing position. The work area contains 5 seismic data volumes, and the relation between each seismic attribute and lithology is comprehensively judged by extracting root mean square amplitude values of the seismic data volumes. Secondly, counting the objective interval mountain of each well according to the dividing result of the stratum on the well ₂ ³ Sub-section formation thickness and sand thickness. And calculating the sand content of the stratum through the stratum thickness and the sand thickness. Finally, a scatter plot of the statistical cross-well point root mean square amplitude value and the calculated cross-well formation sand content is made. The result shows that the sand content has certain correlation with the root mean square amplitude value of each seismic attribute, wherein the correlation between the root mean square amplitude of the instantaneous frequency and the sand content is better, R ² 0.4743. It can be stated that the amplitude attribute is to some extent effective in predicting sandstone.

2. Multi-attribute fusion analysis

The scheme adopts cluster analysis seismic attribute fusion. Using SPSS software, pearson (Pearson) correlation analysis based on bayesian statistical theory, and establishing the correlation between sand content and each seismic attribute is shown in table 5-2. The superposition attribute has better correlation with the instantaneous frequency attribute and the oil gas detection attribute, and the correlation coefficient R is respectively 0.529 to 0.704 and has poorer correlation with the speed attribute and the crack attribute; the instantaneous frequency has good correlation with the oil gas detection attribute, and the correlation coefficient R is-0.626; the correlation between the crack attribute and the speed attribute is good, and the correlation coefficient R is-0.530. Therefore, the method classifies better correlation into one class according to the principle of cluster analysis. The research divides the seismic attribute body into two types, wherein the superposition attribute, the instantaneous frequency attribute and the oil gas detection attribute are classified into one type (I type), and the velocity attribute and the crack attribute are classified into one type (II type).

TABLE 5-2 mountain and western group mountain of research area ₂ ³ Analysis of correlation between sand content and seismic attribute of sub-section

After cluster analysis, fusion attribute analysis is preferably performed on the seismic attributes and the attributes with good sand content correlation. In the class I attribute, the instantaneous frequency attribute has better correlation with the oil gas detection attribute and the sand content, the correlation coefficient is R0.689-0.400 respectively, and the instantaneous frequency attribute has better correlation, so the instantaneous frequency attribute is preferable in the class I attribute. Among the class II attributes, the fracture attribute has better correlation with the sand content, the correlation coefficient R is-0.508, and the relation between the velocity attribute and the sand content is poorer, so the fracture attribute is preferable among the class II attributes. Based on SPSS software, the relation between sand bodies and seismic attributes is established by taking sand content as a dependent variable and instantaneous frequency attribute and fracture attribute as independent variables. After analysis of the fusion attribute, the correlation between the sand content and the seismic attribute is obviously improved, and R is 0.774, as shown in figure 3. And calculating a plane phase diagram of the sand body by Petrel software, and describing the plane spreading characteristics of the sand body. The sand body is distributed in a north-south manner, and the direction of the object source in the research area is north and is consistent with the direction of the object source. Wherein, the sand bodies in the north part are distributed in the northeast and west directions, gradually shrink in the south direction, and then gradually increase in the south part.

Secondly, according to the aboveground stratum division result, counting stratum thickness and sand thickness of stratum PSQ1, PSQ2, PSQ3 and PSQ4 of each well purpose, establishing a relation between sand content and seismic attribute of each small layer through SPSS software, and describing a sand plane phase diagram of each small layer. The sand body is integrally distributed in a south-north manner and is matched with mountain ₂ ³ The subsections remain substantially identical. And the sand content of the two small layers of PSQ1 and PSQ2 is higher, and the sand content of the small layers of PSQ3 and PSQ4 evolving upwards is gradually reduced, so that the sand content is more consistent with the bottom-up evolution characteristics of the actual stratum sandstone.

Mountain characterization based on Petrel software ₂ ³ Sub-section and four-level layer sequence grid lower sand plane phase diagram, but at the same time, verification is required to be based on three-dimensional groundThe accuracy of the plane phase diagram of the seismic data. And according to the uphole lithology information, calculating the coincidence rate of sand body distribution of each well passing position of each small layer and each small layer plane phase diagram. The PSQ1 small-layer uphole coincidence rate is 80%, the PSQ2 small-layer uphole coincidence rate is 80%, the PSQ3 small-layer uphole coincidence rate is 50%, the PSQ4 small-layer uphole coincidence rate is 60%, the earthquake interpretation prediction sand content accords with the logging interpretation sand content generally, and the earthquake data may not accurately identify lithology and other problems. Objective layer section mountain of research area ₂ ³ The thickness of the sub-section stratum is about 40m, the thickness of the stratum under the five-level sequence stratum grid is about 2m-3m, the lithology thickness is thinner, and the problems of insufficient seismic interpretation precision and the like exist.

Because the distribution characteristics of the sand bodies cannot be accurately identified by the seismic data, and the aboveground coincidence rate is poor, the plane distribution characteristics of the sand bodies can be established according to aboveground interpretation results. Based on the high-precision stratum grillwork, the distribution characteristics of the sand body are roughly drawn according to lithology thickness and uphole distribution characteristics, and three-dimensional space distribution characteristics of the sand body are depicted in a grading mode. First according to the mountain of the research area ₂ ³ And constructing a model by sub-sections, establishing a lithofacies model of a research area, and uniformly assigning the model to shale, wherein the distribution characteristics of each lithology are described on the basis of the model, as shown in fig. 4.

(1) Interpretation of PSQ1 sandstone distribution characteristics based on logging

1) FSQ1 sandstone distribution characteristics

The main lithology of the FSQ1 layer is sea shale distributed at the top of the Taiyuan group, the lithology is mainly divided into shale, silt shale and carbonaceous shale, wherein the A2 well FSQ1 contains the shale and sandstone, and the thickness of the sandstone is 3.68m at the bottom of the distribution. And (5) describing the spatial distribution characteristics of the sand body according to the lithology thickness and the underground lithology interpretation. Firstly, in the vertical direction, the FSQ1 is provided with 9 grid divisions, namely layer1-layer9 from top to bottom, and the single grid precision is 0.7m. The sand bodies are distributed in layers 5-9 in the vertical direction according to lithology thickness and vertical grid precision. On a plane, the distribution characteristics of the sand body on the plane are approximately carved out according to the aboveground lithology interpretation and lithology thickness. The object source direction of the research area is from north to south, and the FSQ1 layer has sandstone distribution only at the A2 well, so that sandstone gradually pinches out from north to south at the A2 well.

2) FSQ2 sandstone distribution characteristics

The FSQ2 layer bottom sand body is stable in distribution and is the north fork ditch sandstone of the marker layer in the research area. Wherein the sandstone thicknesses of the A1 well, the A2 well, the A3 well, the A4 well, the A5 well and the A6 well are respectively 1.29m, 1.25m, 2.58m, 1.7m, 3.52m and 1.56m. In the vertical direction, the FSQ2 is provided with 13 grid divisions, namely layers 1-13 from top to bottom, and the layers 1-13 are distributed by sand bodies. On the plane, the distribution of the layer13 sand bodies is very wide, the whole research area is basically covered, the distribution range of the layer11-12 sand bodies starts to be reduced, the distribution range of the layer10 sand bodies further reduces until the local distribution (layer 9) is achieved, the layers 1-8 are mostly shale distribution, sandstone is distributed at the A2 well, and the sandstone gradually stops from north to south.

3) FSQ3 sandstone distribution characteristics

The distribution of the sandstone at the well site of the bottom part of the FSQ3 layer is less in the integral distribution of the sandstone in the upward evolution process. Wherein the thickness of sandstone of the A3 well, the A4 well and the A6 well is 3.7m, 2.76m and 1.48m respectively. In the vertical direction, the FSQ3 is provided with 15 grid divisions, the grid divisions are respectively layer1-layer15 from top to bottom, the layer5-layer15 is provided with sandstone distribution, and sandstone is mainly distributed at the lower part of the FSQ 3. On a plane, the layers 12-15 sandstone are distributed on the east and west sides, in the upward evolution process, the distribution range of the layers 8-11 sandstone starts to be increased, then sandstone at the A6 well is eliminated, the layers 6-7 sandstone are distributed on the east and west sides again until the layer5 is distributed on the west side locally, and the layers 1-4 are all shale distributions.

(2) Interpretation of PSQ2 sandstone distribution characteristics based on logging

1) FSQ4 sandstone distribution characteristics

FSQ4 layer integral sandstone is unevenly distributed, and is mainly characterized by wide middle distribution range, less upper and lower distribution and the like. Wherein the thickness of sandstone of the A4 well, the A5 well and the A6 well is 0.8m, 2.8m and 0.97m respectively. In the vertical direction, the FSQ3 is provided with 7 grid divisions, layer1-layer7 are respectively arranged from top to bottom, each layer1-layer7 is provided with sandstone distribution, and sandstone is mainly distributed in the middle of the FSQ 4. On a plane, the layer5-7 sandstones are distributed in a strip shape, in the upward evolution process, the distribution range of the layer4 sandstones starts to be increased, and then the distribution range of the sandstones starts to be reduced, and the layer1-3 sandstones are only distributed locally at the east side.

2) FSQ5 sandstone distribution characteristics

The FSQ5 horizon has less overall sandstone and is mainly characterized by only locally distributing the characteristics in the middle of the research area. Of these, only the A1 well distributes sandstone, 1.32m thick. In the vertical direction, the FSQ5 is provided with 10 grid divisions, namely layer1-layer10 and layer3-layer6 from top to bottom respectively, all have sandstone distribution, and sandstone is mainly distributed in the middle part of the FSQ 4. On a plane, only the layers 3-6 of the A1 well are distributed with sandstones, and the sandstones gradually pinch out from north to east to south.

(3) Interpretation of PSQ3 sandstone distribution characteristics based on logging

1) FSQ6 sandstone distribution characteristics

The FSQ6 layer has wide overall sandstone distribution, and is mainly characterized in that the lower part of the FSQ6 layer has almost no sandstone distribution, the middle and upper sandstone distribution is more, and the like. Wherein the sandstone thickness of the A1 well, the A2 well, the A5 well and the A6 well is 1.65m, 4.17m, 2.73m and 1.95m respectively. In the vertical direction, the FSQ6 is provided with 13 grid divisions, namely layers 1-13 from top to bottom, wherein the layers 1-9 are respectively provided with sandstone distribution, and sandstone is mainly distributed at the upper middle part of the FSQ 4. On a plane, the distribution range of the layer6-9 sandstone is wider, the distribution range of the layer5 sandstone starts to be reduced in the upward evolution process, the distribution range of the layer1-4 sandstone starts to be increased, the sandstone is widely distributed in the southeast part, and the distribution of the sandstone in the northwest part is less, so that the sandstone is mostly shale.

2) FSQ7 sandstone distribution characteristics

The FSQ7 layer integral sandstone has distribution, but the distribution is less, and the distribution is mainly characterized in the southeast part of a research area. Wherein the A5 sandstone thickness is 3.61m. In the vertical direction, the FSQ7 is provided with 10 grid divisions, namely layers 1-10 from top to bottom, and the layers 1-10 are all distributed by sandstone. On a plane, the layer1-10 sandstone distribution is stable, and the sandstone distribution range is hardly changed in the upward evolution process. Sandstone is mainly distributed at the eastern part of a research area, is distributed in the north-south direction as a whole, and is mostly shale in the western part.

3) FSQ8 sandstone distribution characteristics

The FSQ8 layer sandstone is thinner and is mainly characterized in that the upper part of the FSQ8 layer is locally distributed, and the middle and lower parts almost have the characteristics of sandstone distribution and the like. Wherein the thickness of the A3 well and the A5 sandstone is 1.11m and 1.06m respectively, and the thickness variation is not great. In the vertical direction, the FSQ8 is provided with 7 grid divisions, namely layer1-layer7 from top to bottom, the layer1-layer 3 is distributed with sandstone, and sandstone is mainly distributed at the upper middle part of the FSQ 4. On a plane, the distribution of the layer1-3 sandstone is smaller, and the distribution range of the sandstone is kept stable in the upward evolution process.

(4) Interpretation of PSQ4 sandstone distribution characteristics based on logging

1) FSQ9 sandstone distribution characteristics

The FSQ9 layer sandstone is unevenly distributed, and the FSQ9 layer sandstone is mainly characterized by partial distribution in the middle of the FSQ9 layer, less distribution of sandstone at the upper part and the lower part, and the like. Wherein the thickness of the A1 well, the A2 well and the A5 sandstone is respectively 1.02m, 4.82m and 1.04m, and the thickness change is larger. In the vertical direction, the FSQ9 is provided with 8 grid divisions, layer1-layer8 are respectively arranged from top to bottom, and each layer1-7 has sandstone distribution. On a plane, the distribution of layer7 sandstone is smaller, in the upward evolution process, the distribution range of layer5-6 sandstone is increased, the distribution range of layer4 sandstone is in a strip shape from north to south and is distributed in a research area, the distribution range of layer4 sandstone is reduced, and the distribution range of layer1-3 sandstone is locally increased, similar to layer 7.

2) FSQ10 sandstone distribution characteristics

The FSQ10 layer sandstone distribution is stable. Wherein the A4 well sandstone thickness is 3.48m. In the vertical direction, the FSQ9 is provided with 8 grid divisions, namely layers 1-8 from top to bottom, and the layers 1-8 are all distributed with sandstone. On a plane, sandstone is distributed stably, distributed in a research area in a strip shape from north to south, and gradually pinch out.

5.2.2 coal seam lithofacies model

The method is based on sandstone plane facies characterization, and further characterizes the distribution of coal seams in the research area through seismic attributes.

(1) Single attribute analysis

Mountain extracted by Petrel software based on the foregoing ₂ ³ And further analyzing the relation between the root mean square amplitude value of each seismic attribute and the coal seam. Counting the objective interval mountain of each well according to the well stratum division result ₂ ³ Sub-section formation thickness and coal seam thickness. Calculation of formation and coal seam thicknessThe formation contains coal. And finally, making a statistical root mean square amplitude value of the well passing point and a calculated scatter diagram of the thickness and the coal content of the stratum coal layer on the well passing through the well. The result shows that the correlation between the coal content and the root mean square amplitude value of each seismic attribute is poor, and the correlation between the coal seam thickness and the root mean square amplitude value of each seismic attribute is good, so that the research mainly characterizes the coal seam distribution through the correlation between the coal seam thickness and the seismic attribute value. Wherein the correlation between the velocity root mean square amplitude and the coal seam thickness is good, R ² 0.6375. It can be stated that the amplitude attribute is also effective in predicting the coal seam to some extent.

(2) Multi-attribute fusion analysis

And (3) establishing the correlation between the thickness of the coal seam and each seismic attribute by adopting cluster analysis seismic attribute fusion and based on Pearson correlation analysis of Bayesian statistical theory (Table 5-3). According to the clustering analysis principle and the previous division result, the superposition attribute, the instantaneous frequency attribute and the oil gas detection attribute are classified into one type (I type), and the speed attribute and the crack attribute are classified into one type (II type).

TABLE 5-3 mountain and western group mountain of research district ₂ ³ Analysis of correlation of thickness and seismic properties of sub-section coal seam

After cluster analysis, fusion attribute analysis is preferably performed on the attributes with good correlation between the seismic attributes and the coal seam thickness. In the class I attribute, the superposition attribute, the instantaneous frequency attribute and the coal seam thickness have better correlation, the correlation coefficient R is 0.485 and 0.616 respectively, and the instantaneous frequency attribute has better correlation, so that the instantaneous frequency attribute is preferable in the class I attribute. In the class II attribute, the correlation of the velocity attribute, the crack attribute and the thickness of the coal layer is good, the correlation coefficient R is-0.798 and 0.600 respectively, and the correlation of the velocity attribute and the thickness of the coal layer is better, so that the velocity attribute is preferable in the class II attribute. Based on SPSS software, the relationship between the coal seam and the seismic attribute is established by taking the thickness of the coal seam as a dependent variable and the instantaneous frequency attribute and the speed attribute as independent variables. After analysis of fusion attribute, the correlation between the thickness of the coal layer and the seismic attribute is obviously improved, and R is 0.878. And calculating a plane phase diagram of the coal bed through Petrel software, and describing the plane spreading characteristics of the coal bed. The overall distribution characteristics of the coal seam in the research area are similar to those of sandstone, the coal seam in the north is distributed in the east-west direction, the distribution of the coal seam in the south is gradually reduced, and then the distribution of the coal seam in the south is gradually increased. Based on this phenomenon, it is believed that the seismic attributes are able to identify the distribution characteristics of the two lithologies of sandstone and coal, but cannot distinguish them.

Secondly, according to the dividing result of the underground stratum, the stratum thickness and the coal layer thickness of each small layer PSQ1, PSQ2, PSQ3 and PSQ4 of each underground stratum section are counted, wherein the small layer PSQ1 contains less coal, the statistics of underground data points is insufficient, the correlation between the seismic attribute and the coal layer thickness cannot be established, and the distribution of the PSQ4 coal layer at the top is 5 ^# The coal marking layer is distributed stably in the research area. And establishing the relation between the thickness and the seismic attribute of the PSQ2 and PSQ3 coal beds through SPSS software, and describing the plane phase diagram of each small coal bed. The whole coal bed presents south-north spread and mountain-like spread ₂ ³ The belly characteristics of the sub-section coal seam basically keep consistent, the PSQ2 small-layer coal seam is thinner, the upward evolution PSQ3 coal seam is thicker, and the distribution range is wider. However, the distribution characteristics of the coal seam are similar to those of sandstone, and the seismic attribute cannot completely distinguish the sandstone from the two lithologies of the coal seam.

Mountain characterization based on Petrel software ₂ ³ The thickness plan of the coal bed under the sub-section and four-level layer sequence grids is required to be verified, and the correctness of the plan phase diagram based on the three-dimensional seismic data is required to be verified. And according to the uphole lithology information, calculating the coincidence rate of the coal seam distribution of each well crossing position of each small layer and each small layer plane phase diagram. The PSQ2 small-layer uphole coincidence rate is 60%, and the PSQ3 small-layer uphole coincidence rate is 40%, so that the problems of lithology and the like can not be accurately identified by the seismic data.

Because the distribution characteristics of sandstone and coal beds cannot be accurately identified by the seismic data, and the aboveground coincidence rate is poor, the plane spreading characteristics of the coal beds can be established according to aboveground interpretation results. Based on the high-precision stratum grillwork, the distribution characteristics of the coal bed are roughly drawn, and the three-dimensional space distribution characteristics of the coal are depicted in a grading manner. Although the coal seam distribution in the research area is wider, the distribution of each horizon is not necessarily present, so that the horizons of the coal seam distribution are selected for depiction.

(1) Interpreting PSQ1 coal seam distribution characteristics based on logging

1) FSQ3 coal seam profile

The FSQ3 horizon coal seam distribution is stable. Wherein the thickness of the coal layer of the A2 well is 1.83m. In the vertical direction, the FSQ9 is provided with 8 grid divisions, and coal beds are respectively distributed for layers 1-8 and layers 1-4 from top to bottom. On a plane, the coal seam is distributed more stably, and is distributed in a research area from north to south, as shown in fig. 5;

(2) Interpreting PSQ2 coal seam distribution characteristics based on logging

1) FSQ5 coal seam profile

The FSQ5 horizon coal seam distribution is stable. Wherein the coal seam thicknesses of the A1 well, the A3 well and the A5 well are 0.83m, 0.76m and 1.48m. In the vertical direction, the FSQ9 is provided with 8 grid divisions, and coal beds are respectively distributed for layers 1-8 and layers 1-4 from top to bottom. On the plane, the layer6 coal bed is distributed on the eastern side of the research area, the upward evolution coal bed distribution range is enlarged, the layer1 coal bed is distributed most widely, and the distribution is from north to south in the research area.

(3) Interpreting PSQ3 coal seam distribution characteristics based on logging

1) FSQ7 coal seam profile

The FSQ7 horizon coal seam distribution range has larger change, and is characterized by wider lower coal seam distribution range in the horizon, reduced upper coal seam distribution range and the like. The thickness of the coal seam of the A3 well and the A6 well is 1.94m and 1.38m. In the vertical direction, the FSQ7 is provided with 10 grid divisions, and the coal beds are respectively distributed from top to bottom in layers 1-10, and the layers 1-10 are uniformly distributed. On the plane, the layer5-10 coal beds are distributed on the west side of the research area, in the upward evolution process, the distribution range of the layer3-4 coal beds is increased, and the distribution range of the layer1-2 coal beds is reduced and mainly distributed on the south side of the research area.

2) FSQ8 coal seam profile

The FSQ8 layer coal layer is scattered in the research area. The coal seam thicknesses of the A1 well, the A2 well and the A3 well are 0.9m, 1.27m and 0.78m. In the vertical direction, the FSQ8 is provided with 7 grid divisions, and coal beds are distributed for layers 1-7, layers 1-2 and layers 6-7 from top to bottom respectively. On a plane, the layer6-7 coal beds are distributed on the western side of a research area, and the distribution range is smaller; in the upward evolution process, the layer1-2 coal beds are distributed in the north part of the research area, the thickness change of the coal beds is small, and the distribution is stable. .

(4) Interpreting PSQ4 coal seam distribution characteristics based on logging

1) FSQ11 coal seam profile

The FSQ11 horizon coal seam has wide distribution range and is a research area marking layer 5 ^# And (3) a coal seam. The coal seam thicknesses of the A1 well, the A2 well, the A3 well, the A4 well, the A5 well and the A6 well are respectively 1.33m, 1.21m, 0.97m, 2m, 1.42m and 1.02m. In the vertical direction, the FSQ11 is provided with 10 grid divisions, namely layers 1-10 from top to bottom, and the FSQ11 mainly distributes coal beds at the upper parts (layers 1-4). And on the plane, the layer4 coal beds are distributed in a connecting piece mode, in the upward evolution process, the distribution range of the layer3 coal beds is gradually increased, and then the distribution range of the layer1-2 coal beds is distributed in the whole research area.

5.2.3 carbonate lithofacies model

The Taiyuan group in the research area develops multi-stage limestone, which is Mao Ergou limestone, chute limestone and east daycare limestone from bottom to top respectively. Dongda kiln limestone develops on top of the Taiyuan group and is deposited in the area of investigation as a carbonate bench. Dongda kiln limestone is used as a regional marking layer, is a boundary line between a Taiyuan group and a Shanxi group, is widely and stably distributed in a downhole section in a research area, and has uneven thickness and a variation range of 6m-13m.

Based on the characteristics of distribution stability and the like of limestone in an research area of Dongda kiln, when a carbonate lithofacies model is established, a Taiyuan group at the bottom of the model is assigned as limestone as shown in figure 6.

5.2.4 shale lithofacies model

Because the distribution characteristics of sandstone and coal beds cannot be accurately identified by the seismic data, and the aboveground coincidence rate is poor, when a shale lithofacies model is established, the planar distribution characteristics of shale are approximately calculated according to aboveground interpretation results. And (3) based on the high-precision stratum grillwork, the plane phase characteristics of the powder sand shale, the carbonaceous shale and the shale are depicted.

1. Powder sand shale

(1) Interpreting PSQ1 powder sand shale distribution characteristics based on logging

1) FSQ1 powder sand shale profile

The main lithology of the FSQ1 layer is sea shale distributed at the top of the Taiyuan group, and the lithology is mainly divided into shale, silt shale and carbonaceous shale. Wherein the thicknesses of the powder sand shale of the A1 well, the A4 well and the A6 well are respectively 1.39m, 3.03m and 2.94m. In the vertical direction, the FSQ1 is provided with 9 grid divisions, namely layers 1-9 from top to bottom. The Layer1-Layer9 powder sand shale is distributed and stable in distribution. On a plane, the silty shale is distributed in a strip shape from north to south as shown in fig. 7.

2) FSQ2 powder sand shale profile

The FSQ2 horizon powder sand shale has larger distribution range change, and is characterized by wider distribution in the middle of the horizon, less distribution in the upper part and the lower part, and the like. Wherein the thicknesses of the powder sand shale of the A1 well, the A2 well and the A4 well are 2.37m, 3.07m and 2.4m respectively. In the vertical direction, the Layer1-Layer13 powder sand shale is distributed. On a plane, the layer13 powder sand shale is less in distribution, and in the upward evolution process, the range of the powder sand shale is gradually increased, and then the powder sand shale is gradually reduced and distributed on the north side of a research area.

3) FSQ3 powder sand shale profile

The FSQ3 horizon powder sand shale has larger distribution range change, and is characterized by wider distribution at the upper part of the horizon, less distribution at the middle and lower parts of the horizon, and the like. Wherein the thicknesses of the powder sand shale of the A1 well, the A3 well, the A4 well, the A5 well and the A6 well are respectively 0.7m, 1.24m, 2.26m, 1.55m and 1.26m. In the vertical direction, the Layer1-Layer15 powder sand shale is distributed. On a plane, the layer12-15 powder sand shale is distributed in a strip shape from north to south, and in the upward evolution process, the range of the powder sand shale is gradually reduced, and then the powder sand shale is gradually stabilized and distributed on the east and west sides of a research area.

(2) Interpreting PSQ2 powder sand shale distribution characteristics based on logging

1) FSQ4 powder sand shale profile

The FSQ4 horizon powder sand shale has larger distribution range change, and is characterized by wider distribution at the upper part of the horizon, less distribution at the middle and lower parts of the horizon, and the like. Wherein the thicknesses of the powder sand shale of the A1 well, the A3 well, the A5 well and the A6 well are respectively 1.06m, 3.76m, 1.46 and 1.47m. In the vertical direction, the Layer1-Layer7 powder sand shale is distributed. On a plane, the layer6-7 powder sand shale is distributed on the east and west sides of a research area, and in the upward evolution process, the range of the powder sand shale is gradually reduced, and then the powder sand shale is distributed in the middle of the research area and gradually reduced.

2) FSQ5 powder sand shale profile

The FSQ5 horizon powder sand shale has a smaller distribution range. Wherein the thicknesses of the powder sand shale of the A3 well and the A4 well are 2.58m and 3.34m respectively. In the vertical direction, the Layer3-Layer10 distributes the silty shale, and the silty shale at the top of the Layer does not develop. On a plane, the layer8-10 powder sand shale is distributed on the north side of a research area, and in the upward evolution process, the range of the powder sand shale is gradually enlarged and then is stably distributed in the middle of the research area.

(3) Interpreting PSQ3 powder sand shale distribution characteristics based on logging

1) FSQ6 powder sand shale profile

The FSQ6 horizon powder sand shale distribution range is obviously reduced. Wherein the thicknesses of the powder sand shale of the A1 well and the A4 well are respectively 1.05m and 1.96m. In the vertical direction, the layer5-layer9 distributes the silty shale, and the silty shale at the top of the layer does not develop. On a plane, the layer10-13 powder sand shale locally develops on the north side of the research area, the distribution range of the powder sand shale is increased in the upward evolution process, the layer6-9 powder sand shale is distributed in the middle of the research area, and the layer5 powder sand shale only locally develops on the northeast side of the research area.

2) FSQ7 powder sand shale profile

The FSQ7 horizon powder sand shale has a smaller distribution range and only locally develops at the A1 well. Wherein the thickness of the A1 well powder sand shale is 3.9m respectively. In the vertical direction, the layers 1-10 distribute the powder sand shale evenly. On a plane, the powder sand shale distribution is distributed stably in a research area.

3) FSQ8 powder sand shale profile

FSQ8 layer silty shale develops in the south of the research area, and the distribution range is stable. Wherein the thickness of the A6 well powder sand shale is 1.74m respectively. In the vertical direction, the layers (layer 1-layer 3) are distributed with the silty shale, and the middle-lower silty shale does not develop. On a plane, the powder sand shale is stably distributed on the south side of a research area, and the range of the powder sand shale is not greatly changed in the upward evolution process.

(4) Interpreting PSQ4 powder sand shale distribution characteristics based on logging

1) FSQ9 powder sand shale profile

The FSQ9 horizon powder sand shale distribution range varies greatly. Wherein the thicknesses of the powder sand shale of the A3 well and the A4 well are respectively 0.84m and 2.56m. In the vertical direction, the layers 1-8 uniformly distribute the silty shale. On a plane, the layer8 powder sand shale is distributed on the north side of a research area, and in the upward evolution process, the range of the powder sand shale is gradually expanded and then stably distributed on the west side of the research area.

2. Carbonaceous shale

(1) Interpreting PSQ1 carbonaceous shale distribution characteristics based on logging

1) FSQ1 carbonaceous shale profile

The FSQ1 horizon carbonaceous shale has small change in distribution range and basically develops at the eastern side of the research area. Wherein the thickness of the carbonaceous shale of the A5 well is 1.19m respectively. In the vertical direction, layers 1-9 distribute carbonaceous shale evenly. On the plane, carbonaceous shale is distributed on the north side of the research area, and the distribution is stable in the upward evolution process, as shown in fig. 8.

2) FSQ2 carbonaceous shale profile

The FSQ2 horizon carbonaceous shale distribution range varies less, and also develops substantially to the eastern side of the study area. Wherein the thickness of the carbonaceous shale in the A1 well, the A5 well and the A6 well is 1.05m, 4.71m and 1.18m respectively. In the vertical direction, layers 1-8 distribute carbonaceous shale. On the plane, the carbonaceous shale is distributed on the eastern side of the research area, and in the upward evolution process, the development range of the carbonaceous shale is increased, and the distribution is stable.

3) FSQ3 carbonaceous shale profile

The FSQ3 horizon carbonaceous shale has a smaller distribution range and basically develops on the north side of the research area. Wherein the A4 well carbonaceous shale has a thickness of 1.72m. In the vertical direction, layers 1-4 and layers 5-6 distribute carbonaceous shale. On the plane, the carbonaceous shale is distributed on the north side of the research area, and in the upward evolution process, the development range of the carbonaceous shale is increased, and the distribution is stable.

(2) Interpreting PSQ2 carbonaceous shale distribution characteristics based on logging

1) FSQ4 carbonaceous shale profile

The distribution range of the FSQ4 layer carbonaceous shale is changed greatly, the distribution of the lower part of the layer carbonaceous shale is less, and the distribution range of the upper part of the layer carbonaceous shale is more. Wherein the thickness of the carbonaceous shale in the A3 well and the A4 well is 0.88m and 3m respectively. In the vertical direction, layers 1-2 and 5-7 distribute carbonaceous shale. On the plane, the carbonaceous shale is mainly distributed on the north side of the research area, and in the upward evolution process, the distribution range of the carbonaceous shale is increased and is mainly distributed on the west side of the research area.

2) FSQ5 carbonaceous shale profile

FSQ5 horizon carbonaceous shale is less extensive and develops only on top of the horizon. Wherein the thickness of the carbonaceous shale of the A6 well is 0.68m respectively. In the vertical direction, the horizon carbonaceous shale is thinner in thickness, and layer1 distributes carbonaceous shale. On a planar basis, carbonaceous shale is predominantly distributed on the south side of the investigation region.

(3) Interpreting PSQ3 carbonaceous shale distribution characteristics based on logging

1) FSQ6 carbonaceous shale profile

The FSQ6 layer has larger distribution range of carbonaceous shale, the carbonaceous shale at the lower part of the layer has more distribution, and the carbonaceous shale at the upper part does not develop basically. Wherein the thickness of the carbonaceous shale in the A3 well and the A5 well is 0.98m and 1.05m respectively. In the vertical direction, layers 9-13 distribute carbonaceous shale. On the plane, carbonaceous shale is mainly distributed on the east and west sides of the research area, and in the upward evolution process, eastern carbonaceous shale gradually disappears and is mainly distributed on the west side of the research area.

2) FSQ7 carbonaceous shale profile

The FSQ7 horizon carbonaceous shale distribution range is stable, and the horizon top develops carbonaceous shale. Wherein the thickness of the carbonaceous shale of the A3 well is 0.54m respectively. In the vertical direction, the horizon carbonaceous shale is thinner and only carbonaceous shale is distributed in layers 1-2. On the plane, the carbonaceous shale is mainly distributed on the two sides of the research area, and in the upward evolution process, the development of the carbonaceous shale is stable.

3) FSQ8 carbonaceous shale profile

The FSQ8 horizon carbonaceous shale distribution range is smaller, with upper and lower horizons carbonaceous shale distributions. Wherein the thickness of the carbonaceous shale in the A1 well and the A4 well is 0.74m and 2.18m respectively. In the vertical direction, layers 2-3 and layers 6-7 distribute carbonaceous shale. On the plane, the carbonaceous shale is mainly distributed on the north side of the research area, and in the upward evolution process, the A1 well locally develops the carbonaceous shale and is distributed with the A4 well carbonaceous shale in a connecting way.

(4) Interpreting PSQ4 carbonaceous shale distribution characteristics based on logging

1) FSQ9 carbonaceous shale profile

FSQ10 is thinner and distributed above and below the horizon. Wherein the thickness of the carbonaceous shale in the A2 well and the A5 well is 0.7m and 0.76m respectively. In the vertical direction, layers 1 and 8 distribute carbonaceous shale. On a plane, the lower carbonaceous shale is distributed on the north side of the investigation region, and during the upward evolution, the north carbonaceous shale disappears and is mainly distributed on the east side of the investigation region.

2) FSQ10 carbonaceous shale profile

FSQ10 horizon carbonaceous shale is thinner, and the distribution scope is comparatively stable, and mainly distributes at the horizon top, and the rest does not develop. Wherein the A6 well carbonaceous shale has a thickness of 0.82m. In the vertical direction, layers 1-2 distribute carbonaceous shale. On the plane, carbonaceous shale is mainly distributed on the north side of the research area, and the distribution is stable.

3) FSQ11 carbonaceous shale profile

FSQ11 horizon carbonaceous shale distribution range changes greatly, carbonaceous shale distributes more, and the whole horizon develops almost carbonaceous shale, and top development marking layer 5 ^# And (3) a coal seam. Wherein the thickness of the carbonaceous shale in the A1 well, the A2 well and the A4 well is 1.12m, 4.93m and 1.12m respectively. In the vertical direction, layers 3-10 distribute carbonaceous shale. On the plane, the carbonaceous shale is mainly distributed on the north side of the research area, the distribution range of the carbonaceous shale on the north side is gradually increased in the upward evolution process, then gradually faded, and finally, the carbonaceous shale is locally developed on the north side of the research area.

3. Shale

The model takes shale as a substrate, and the distribution characteristics of sandstone, coal bed, powder sand shale and carbonaceous shale in a three-dimensional space are carved under a high-precision stratum grid, and the rest parts are assigned to be shale.

Establishing mountain and western group mountain of east edge A well region of Erdos basin by each small layer step-by-step deterministic lithofacies modeling ₂ ³ The lithofacies model of the subsections is shown in fig. 9. And the three-dimensional space spreading characteristics of each lithofacies lay a more reliable foundation for the establishment of a subsequent attribute model.

Mountain and western mountain group mountain from east edge A well region of Erdos basin ₂ ³ The three-dimensional geological model of the lithofacies of the subsections can be seen, and the whole mountain ₂ ³ The minor segment sandstone is mainly distributed on the two sides of the research area, the sandstone is less in the middle, and the sandstone is in opposite trend with the shale in thickness and plane distribution. Whole mountain ₂ ³ The shale is thinner in the sub-section sandstone development area and distributed in the interior of the sub-section sandstone development area in a sand mud thin interbedded mode, and in the sandstone relatively undeveloped area, the thickness of the sandstone is thinner, and the shale and the sandstone are distributed in the research area in a mutually-eliminated trend. In the three-dimensional geological model, sandstone is distributed in mountains ₂ ³ The bottom and the upper part of the sub-section, wherein the bottom is the North fork ditch sandstone, the North fork ditch sandstone is more stable and distributed in the research area in a connecting way, but the North fork ditch sandstone in a local area does not develop, for example, the research area is in the North direction, and the lower part of the research area develops shale and is not in integrated contact with carbonate rock. The sandstone on the upper part is mainly distributed on the north and the east of the research area, the sandstone on the east A5 well is thicker, the connectivity is better along the direction of the material source, and the shale is mostly developed in the inside in a thin layer.

The coal layer in the research area is thinner, the thickness is between 0.7m and 2m, and the coal layer and the carbonaceous shale layer are mostly developed in the research area. In the three-dimensional geological model, the coal seam is distributed on mountains ₂ ³ The top and the middle of the sub-section, wherein the top is a research area marking layer 5 ^# Coal, with a thickness between 0.97m and 2m, is stably and continuously distributed in the investigation region. The middle coal seam is thinner and is mostly distributed at the west of the research area.

Shale develops in the middle A1 well, the north A2 well, the A4 well and the like of the research area, the thickness is between 20 and 30m, and the longitudinal connectivity is good. Wherein the powder sand shale at the A2 well and the A4 well at the north part is developed and distributed in the mountain in a connecting way ₂ ³ At the bottom of the sub-section, in the middle of the research area, the whole powder sand shale is relatively thin, the powder sand shale mainly develops, the powder sand shale at the bottom does not develop any more, and the North bifurcation sulcus sandstone mainly exists. To the south A6 well, the powder sand shale develops gradually and is distributed in the mountain ₂ ³ The bottom and the upper part of the sub-section. The carbonaceous shale is relatively thin as a whole, has small thickness and poor longitudinal continuity, and is mainly distributed on mountains ₂ ³ The bottom and the middle of the sub-section. In the eastern A5 well of the research area, the carbonaceous shale is most developed, the thickness of the carbonaceous shale gradually decreases and disappears in the middle evolution process, and the carbonaceous shale gradually develops in the western A3 well and is distributed in the mountain ₂ ³ The middle part of the sub-section is mutually layered with the coal seam. Carbonaceous shale is characterized by thicker east and west and thinner middle. The mud shale distribution characteristics are characterized by thick middle part, thin east and west parts and the like, the thickness is between 10m and 26m, and the mud shale distribution characteristics are opposite to the sandstone and silty shale. Wherein the north A2 well and the north A4 well are distributed on the mountain ₂ ³ The mud shale in the middle and upper part of the sub-section is relatively developed, the laminated sand is stably distributed to the south A6 well, and the mud page is gradually developed and distributed in the mountain ₂ ³ The middle part and the upper part of the sub-section.

In conclusion, the lithofacies model built in the research area accords with the actual evolution rule of the stratum, and provides more reliable basis for subsequent exploration and development

The foregoing is merely a preferred embodiment of the invention, and it is to be understood that the invention is not limited to the form disclosed herein but is not to be construed as excluding other embodiments, but is capable of numerous other combinations, modifications and environments and is capable of modifications within the scope of the inventive concept, either as taught or as a matter of routine skill or knowledge in the relevant art. And that modifications and variations which do not depart from the spirit and scope of the invention are intended to be within the scope of the appended claims.

Claims

1. The method for modeling the three-dimensional lithofacies of the shale of the land-sea transition phase under the stratum grillwork is characterized by comprising the following steps of: