Cloud-ash composite buried hill depicting method and device

Abstract

The invention discloses a cloud-ash composite buried hill depicting method and device, and the method comprises the steps: depicting the top surface of a cloud-ash composite buried hill based on well drilling sound wave data and three-dimensional seismic data; depicting the bottom surface of the cloud-ash composite buried hill based on well drilling data and three-dimensional seismic data; taking an intersection of the cloud-ash composite buried hill top surface and the cloud-ash composite buried hill bottom surface to obtain a cloud-ash composite buried hill boundary; and depicting the boundary of the dolomite buried hill based on three-dimensional seismic data and the boundary of the cloud-ash composite buried hill. According to the method, fine depiction of the dolomite buried hill boundary is realized, and technical support is provided for efficient exploration and development of the dolomite buried hill type oil and gas reservoir; the operation process is simple, and the feasibility is high; and meanwhile, the depicting precision of the dolomite buried hill boundary is improved by utilizing well drilling fine calibration and imaging logging information.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas reservoir exploration and development, and particularly relates to a cloud-ash composite buried hill characterization method and device. Background Art

[0002] The Lower Paleozoic dolomite buried hill is one of the important areas of oil and gas exploration in the Tarim Basin. Well Z5, located in the Tazhong 25 structural belt, obtained high-yield oil and gas flow in the dolomite test of the Lower Cambrian Qiulitag Formation, revealing that the Lower Paleozoic dolomite buried hill has broad exploration prospects. The Cambrian-Ordovician dolomite buried hill is deeply buried. Due to the superposition and transformation of multiple tectonic movements, the occurrence of faults and strata is very complex, and it is difficult to obtain the structural model of the dolomite buried hill below the unconformity surface. At the same time, due to the similar lithology of Ordovician limestone and dolomite, it is difficult to distinguish between limestone and dolomite on 3D seismic data, and the boundary of the dolomite buried hill is difficult to depict. The boundary of the dolomite buried hill is not clearly depicted, which affects the description accuracy of the dolomite buried hill type oil and gas reservoir and restricts the efficient exploration and development of the dolomite buried hill type oil and gas reservoir.

[0003] Currently, there are technologies for determining the vertical interface of buried hills through element combination interpretation diagrams, but there is little research on the technology for depicting the plane boundary of dolomite buried hills. Summary of the invention

[0004] In view of the above problems, the present invention discloses a cloud-ash composite buried hill characterization method, comprising the following steps:

[0005] Based on the well acoustic data and 3D seismic data, the cloud-ash composite buried hill top is depicted;

[0006] Based on the drilling data and 3D seismic data, the bottom of the cloud-ash composite buried hill is depicted;

[0007] Taking the intersection of the cloud-ash composite buried hill top and the cloud-ash composite buried hill bottom to obtain the cloud-ash composite buried hill boundary;

[0008] Based on the 3D seismic data and the dolomite-ash composite buried-hill boundary, the dolomite buried-hill boundary is depicted.

[0009] Furthermore, the specific steps of describing the top of the cloud-ash composite buried hill based on the well acoustic data and 3D seismic data are as follows:

[0010] Use the acoustic data from the wells to create synthetic seismic records;

[0011] The synthetic seismic record is calibrated with the three-dimensional seismic data to determine the seismic reflection event axis corresponding to the top of the cloud-ash composite buried hill;

[0012] Based on the seismic reflection phase axis, the surface layer of the cloud-ash composite buried hill is interpreted on the three-dimensional seismic data;

[0013] According to the results of the stratigraphic interpretation of the cloud-ash composite buried-mountain top, structural mapping is carried out to depict the cloud-ash composite buried-mountain top.

[0014] Furthermore, the specific steps of describing the bottom of the cloud-ash composite buried hill based on the drilling data and the three-dimensional seismic data are as follows:

[0015] Based on the drilling data, imaging logging interpretation is carried out to obtain the bottom formation dip of the cloud-ash composite buried hill;

[0016] According to the formation dip angle of the cloud-ash composite buried hill bottom, the dip angle of seismic reflection event axis of the cloud-ash composite buried hill bottom is determined on 3D seismic data;

[0017] According to the dip angle of seismic reflection event axis of the bottom surface of cloud-ash composite buried hill, the bottom surface of cloud-ash composite buried hill is interpreted on 3D seismic data;

[0018] According to the results of the stratigraphic interpretation of the bottom of the cloud-ash composite buried hill, structural mapping is carried out to depict the bottom of the cloud-ash composite buried hill.

[0019] Furthermore, the specific steps of describing the dolomite buried hill boundary based on the three-dimensional seismic data and the dolomite-ash composite buried hill boundary are as follows:

[0020] According to the three-dimensional seismic data and the characterization results of the cloud-ash composite buried hill top, the vertical time window is set at different lengths along the upper and lower sides of the cloud-ash composite buried hill top to extract the sensitive attributes of the fracture-vuggy reservoir;

[0021] Calibrate a first threshold value for the sensitive attribute of the fracture-vuggy reservoir according to the drilling data;

[0022] According to the first threshold value of the sensitive attribute of the fracture-vuggy reservoir, the range of dolomite is determined to obtain the attribute characterization result of the boundary of the dolomite buried hill;

[0023] The intersection of the dolomite-ash composite buried-hill boundary characterization results and the dolomite buried-hill boundary attribute characterization results is taken to obtain the dolomite buried-hill boundary characterization results.

[0024] Furthermore, the fracture-vuggy reservoir sensitive attribute is a root mean square amplitude attribute.

[0025] Furthermore, the specific steps of calibrating the first threshold value of the sensitive attribute of the fracture-vuggy reservoir according to the drilling data are as follows:

[0026] According to the drilling data, when the absolute value of the drilling time difference between two adjacent points in the reservoir is greater than the second threshold, the root mean square amplitude attribute value at the point where the drilling time becomes smaller is the first threshold.

[0027] Furthermore, the second threshold value is in the range of 20-30 min / m.

[0028] The present invention also discloses a cloud-ash composite buried hill characterization device, comprising:

[0029] The top surface unit is used to characterize the top surface of the cloud-ash composite buried mountain based on the well acoustic data and 3D seismic data;

[0030] A bottom surface unit is used to describe the bottom surface of the cloud-ash composite buried hill based on the drilling data and the three-dimensional seismic data;

[0031] An intersection unit is used to take the intersection of the cloud-ash composite buried hill top and the cloud-ash composite buried hill bottom to obtain a cloud-ash composite buried hill boundary;

[0032] The boundary unit is used to characterize the dolomite buried hill boundary based on the three-dimensional seismic data and the dolomite-ash composite buried hill boundary.

[0033] Furthermore, the top surface unit is specifically used for:

[0034] Use the acoustic data from the wells to create synthetic seismic records;

[0035] The synthetic seismic record is calibrated with the three-dimensional seismic data to determine the seismic reflection event axis corresponding to the top of the cloud-ash composite buried hill;

[0036] Based on the seismic reflection phase axis, the surface layer of the cloud-ash composite buried hill is interpreted on the three-dimensional seismic data;

[0037] According to the results of the stratigraphic interpretation of the cloud-ash composite buried-mountain top, structural mapping is carried out to depict the cloud-ash composite buried-mountain top.

[0038] Furthermore, the bottom surface unit is specifically used for:

[0039] Based on the drilling data, imaging logging interpretation is carried out to obtain the bottom formation dip of the cloud-ash composite buried hill;

[0040] According to the formation dip angle of the cloud-ash composite buried hill bottom, the dip angle of seismic reflection event axis of the cloud-ash composite buried hill bottom is determined on 3D seismic data;

[0041] According to the dip angle of seismic reflection event axis of the bottom surface of cloud-ash composite buried hill, the bottom surface of cloud-ash composite buried hill is interpreted on 3D seismic data;

[0042] According to the results of the stratigraphic interpretation of the bottom of the cloud-ash composite buried hill, structural mapping is carried out to depict the bottom of the cloud-ash composite buried hill.

[0043] Compared with the prior art, the embodiments of the present invention have at least the following advantages:

[0044] 1. The fine delineation of the dolomite buried-hill boundary is achieved, providing technical support for the efficient exploration and development of dolomite buried-hill oil and gas reservoirs;

[0045] 2. The operation process is simple and highly feasible. At the same time, the precision of dolomite buried hill boundary delineation is improved by using the fine calibration and imaging logging data of the drilled wells.

[0046] 3. It has good application effect and driving value to the same industry.

[0047] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 A flow chart of a cloud-ash composite buried hill characterization method according to an embodiment of the present invention is shown;

[0050] Figure 2 It shows the typical seismic profile characteristics of dolomite and limestone dissolution differences according to an embodiment of the present invention;

[0051] Figure 3 The seismic profile interpretation of the top and bottom of the cloud-ash composite buried hill according to an embodiment of the present invention is shown;

[0052] Figure 4 A histogram of the bottom surface stratum dip angle of a cloud-ash composite buried hill according to an embodiment of the present invention is shown;

[0053] Figure 5 The dolomite buried hill boundary characterization result according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] Figure 1 FIG. 2 shows a flow chart of a cloud-ash composite buried hill characterization method according to an embodiment of the present invention. Figure 1 As shown, a cloud-ash composite buried hill characterization method proposed in the present invention comprises the following steps:

[0056] Step 1: Based on the well acoustic data and 3D seismic data, characterize the cloud-ash composite buried mountain top;

[0057] 1.1. Use the acoustic wave data from the wells to make synthetic seismic records.

[0058] 1.2. Perform well-seismic calibration on the synthetic seismic records obtained in step 1.1 and the three-dimensional seismic data to determine the seismic reflection event axis corresponding to the top of the cloud-ash composite buried hill.

[0059] 1.3. According to the seismic reflection event corresponding to the cloud-ash composite buried-mountain top determined in step 1.2, the cloud-ash composite buried-mountain top stratigraphic interpretation is carried out on the 3D seismic data; illustratively, the interpretation accuracy is that the intervals between the horizontal and vertical survey lines are both 1, that is, 1×1 interpretation density.

[0060] 1.4. According to the stratigraphic interpretation results of the cloud-ash composite buried-mountain top obtained in step 1.3, structural mapping is performed to depict the cloud-ash composite buried-mountain top.

[0061] Among them, the dolomite-limestone composite buried hill is a composite buried hill of dolomite and limestone, which contains both dolomite and limestone, and is referred to as the dolomite-limestone composite buried hill.

[0062] Although the above description is given by taking the interpretation accuracy of 1 line for both horizontal and vertical survey lines, i.e., 1×1 interpretation density, as an example, the present invention is not limited thereto, and a variety of interpretation densities may be used, such as 2×2, 1×2, 3×3, etc., as long as the principle of the present invention can be implemented.

[0063] Step 2: based on the drilling data and 3D seismic data, characterize the bottom of the cloud-ash composite buried hill;

[0064] 2.1. Based on the drilling data, imaging logging interpretation is carried out to obtain the bottom formation dip of the cloud-ash composite buried hill.

[0065] 2.2. According to the formation dip of the bottom of the cloud-ash composite buried hill obtained in step 2.1, determine the dip of the seismic reflection event of the bottom of the cloud-ash composite buried hill on the three-dimensional seismic data. Among them, due to the poor three-dimensional seismic imaging of the interior of the buried hill, the seismic event of the bottom of the cloud-ash composite buried hill is difficult to track. At the same time, the violent tectonic movement makes the structure of the buried hill complex, and it is necessary to use the imaging logging data of the drilled wells to determine the formation dip of the bottom of the cloud-ash composite buried hill. Since the large structural background is the same, the formation dip at the well can be extrapolated as the formation dip of the bottom of the cloud-ash composite buried hill, which is the dip of the seismic reflection event of the bottom of the cloud-ash composite buried hill on the three-dimensional seismic data.

[0066] 2.3. According to the dip angle of the seismic reflection phase axis of the bottom surface of the cloud-ash composite buried hill obtained in step 2.2, the bottom surface of the cloud-ash composite buried hill is interpreted on the three-dimensional seismic data; for example, the interpretation accuracy is that the interval between the horizontal survey line and the vertical survey line is 1, that is, 1×1 interpretation density. Among them, the dip angle of the seismic reflection phase axis of the bottom surface of the cloud-ash composite buried hill is obtained above. According to this dip angle and the seismic phase axis that can be identified on the bottom surface of the cloud-ash composite buried hill, the bottom surface of the cloud-ash composite buried hill can be interpreted on the three-dimensional seismic data. The bottom surface of the cloud-ash composite buried hill is interpreted from the identifiable seismic phase axis. When the seismic phase axis is unclear and the horizon interpretation cannot be performed, it is started from this point and extrapolated according to the above-mentioned formation dip angle to obtain the bottom surface of the cloud-ash composite buried hill.

[0067] 2.4. According to the results of the stratigraphic interpretation of the bottom of the cloud-ash composite buried hill obtained in step 2.3, structural mapping is performed to depict the bottom of the cloud-ash composite buried hill.

[0068] Step 3: Describe the boundary of the cloud-ash composite buried hill;

[0069] 3.1. Take the intersection of the cloud-ash composite buried hill top characterization result obtained in step 1.4 and the cloud-ash composite buried hill bottom characterization result obtained in step 2.4 to obtain the cloud-ash composite buried hill boundary characterization result.

[0070] Step 4: based on the 3D seismic data and the dolomite-ash composite buried-hill boundary, depict the dolomite buried-hill boundary;

[0071] Under the same geological conditions, since the dissolution degree of limestone is greater than that of dolomite, there will be dissolution fracture-cave reservoirs in the limestone strata. These dissolution fracture-cave reservoirs show strong amplitude reflection characteristics on the seismic profile, while dolomite has stronger dissolution resistance than limestone and shows weak amplitude reflection characteristics on the seismic profile (such as Figure 2 Therefore, the sensitive RMS amplitude attribute of the fracture-vuggy reservoir can be used to characterize the limestone formation, thereby distinguishing dolomite from limestone.

[0072] 4.1. Using the three-dimensional seismic data and the cloud-ash composite buried-mountain top characterization results obtained in step 1.4, the vertical time window is 100 meters above and below the cloud-ash composite buried-mountain top to extract the root mean square amplitude attributes of the fracture-vuggy reservoir sensitive attributes.

[0073] 4.2. Use the drilling data to calibrate the first threshold of the fracture-vuggy reservoir sensitivity attribute obtained in step 4.1. According to the drilling data, since the drilling time will be accelerated when the well is drilled into the fracture-vuggy reservoir, when the absolute value of the drilling time difference between two adjacent points in the reservoir is greater than the second threshold, it is considered that the fracture-vuggy reservoir is drilled, and the root mean square amplitude attribute value of the fracture-vuggy reservoir sensitivity attribute at the point where the drilling time decreases is the first threshold of the fracture-vuggy reservoir sensitivity attribute. Among them, the range of the second threshold is 20-30min / m; preferably, the second threshold is 20min / m.

[0074] 4.3. According to the first threshold of the fracture-vuggy reservoir sensitivity attribute determined in step 4.2, the part less than or equal to the first threshold is dolomite, and the dolomite buried-hill boundary attribute characterization result is obtained.

[0075] 4.4. The intersection of the cloud-ash composite buried hill boundary characterization result obtained in step 3.1 and the dolomite buried hill boundary attribute characterization result obtained in step 4.3 is taken to obtain the dolomite buried hill boundary characterization result.

[0076] Example: The above technology has been successfully applied to a cloud-ash composite buried hill characterization project in the Tazhong area of ​​the Tarim Oilfield. According to step one and step two, the top and bottom interpretation of the cloud-ash composite buried hill is completed. Figure 3 As shown, among which, Figure 4 As shown in Figure 1, the formation dip histogram is made based on the formation dip data obtained from the imaging logging results at the well point. From the histogram, it can be seen that the frequency of 40-50° is the largest, and the average value of 45° is taken as the formation dip. According to steps 3 and 4, the detailed characterization of the dolomite buried hill is achieved. Figure 5 As shown. The dolomite buried hill area was finally determined to be 58.3 square kilometers, and the closed resources handed in were: 1.97 million tons of oil and 12.6 billion cubic meters of gas. Two exploration wells (Z58 and Z582) were deployed in the dolomite buried hill exposed area, both of which were successful. Both wells successfully drilled high-quality dolomite and obtained industrial oil and gas flows. So far, the cumulative oil production is 19,700 tons and the cumulative gas production is 131 million cubic meters.

[0077] The present invention uses high-precision three-dimensional seismic data and drilling data, with the help of imaging logging data, to characterize the plane boundary of the dolomite-limestone composite buried hill. On this basis, it further combines the differences in lithological dissolution of dolomite and limestone, relies on the sensitive properties of fracture-vuggy reservoirs, and determines the plane boundary of the dolomite buried hill, thereby improving the accuracy of dolomite buried hill boundary characterization and providing technical support for the efficient exploration and development of dolomite buried hill oil and gas reservoirs.

[0078] The dolomite-ash composite buried-hill characterization method of the present invention realizes the fine characterization of the dolomite buried-hill boundary, and provides technical support for the efficient exploration and development of dolomite buried-hill oil and gas reservoirs; the operation process is simple and the feasibility is strong; at the same time, the fine calibration and imaging logging data of the drilled wells are used to improve the accuracy of the dolomite buried-hill boundary characterization; it has a good application effect and promotion value to the same industry.

[0079] Based on the above-mentioned cloud-ash composite buried-hill characterization method, the present invention also proposes a cloud-ash composite buried-hill characterization device, comprising:

[0080] The top surface unit is used to characterize the top surface of the cloud-ash composite buried mountain based on the well acoustic data and 3D seismic data;

[0081] A bottom surface unit is used to describe the bottom surface of the cloud-ash composite buried hill based on the drilling data and the three-dimensional seismic data;

[0082] An intersection unit is used to take the intersection of the cloud-ash composite buried hill top and the cloud-ash composite buried hill bottom to obtain a cloud-ash composite buried hill boundary;

[0083] The boundary unit is used to characterize the dolomite buried hill boundary based on the three-dimensional seismic data and the dolomite-ash composite buried hill boundary.

[0084] In some embodiments, the top surface unit is specifically used for:

[0085] Use the acoustic data from the wells to create synthetic seismic records;

[0086] The synthetic seismic record is calibrated with the three-dimensional seismic data to determine the seismic reflection event axis corresponding to the top of the cloud-ash composite buried hill;

[0087] Based on the seismic reflection phase axis, the surface layer of the cloud-ash composite buried hill is interpreted on the three-dimensional seismic data;

[0088] According to the results of the stratigraphic interpretation of the cloud-ash composite buried-mountain top, structural mapping is carried out to depict the cloud-ash composite buried-mountain top.

[0089] In some embodiments, the bottom surface unit is specifically used for:

[0090] Based on the drilling data, imaging logging interpretation is carried out to obtain the bottom formation dip of the cloud-ash composite buried hill;

[0091] According to the formation dip angle of the cloud-ash composite buried hill bottom, the dip angle of seismic reflection event axis of the cloud-ash composite buried hill bottom is determined on 3D seismic data;

[0092] According to the dip angle of seismic reflection event axis of the bottom surface of cloud-ash composite buried hill, the bottom surface of cloud-ash composite buried hill is interpreted on 3D seismic data;

[0093] According to the results of the stratigraphic interpretation of the bottom of the cloud-ash composite buried hill, structural mapping is carried out to depict the bottom of the cloud-ash composite buried hill.

[0094] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present disclosure. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present disclosure, the size of the serial number of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present disclosure. The serial numbers of the embodiments of the present disclosure are for description only and do not represent the advantages and disadvantages of the embodiments.

[0095] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cloud-ash composite buried hill characterization method, characterized in that: The following steps are involved: Based on the well acoustic data and 3D seismic data, the cloud-ash composite buried hill top is depicted; Based on the drilling data and 3D seismic data, the bottom of the cloud-ash composite buried hill is depicted; Taking the intersection of the cloud-ash composite buried hill top and the cloud-ash composite buried hill bottom to obtain the cloud-ash composite buried hill boundary; Based on the 3D seismic data and the dolomite-ash composite buried-hill boundary, the dolomite buried-hill boundary is depicted.

2. The cloud-ash composite buried hill characterization method according to claim 1, characterized in that: The specific steps of describing the top of the cloud-ash composite buried hill based on the well acoustic data and 3D seismic data are as follows: Use the acoustic data from the wells to create synthetic seismic records; The synthetic seismic record is calibrated with the three-dimensional seismic data to determine the seismic reflection event axis corresponding to the top of the cloud-ash composite buried hill; Based on the seismic reflection phase axis, the surface layer of the cloud-ash composite buried hill is interpreted on the three-dimensional seismic data; According to the results of the stratigraphic interpretation of the cloud-ash composite buried-mountain top, structural mapping is carried out to depict the cloud-ash composite buried-mountain top.

3. The cloud-ash composite buried hill characterization method according to claim 1, characterized in that: The specific steps of describing the bottom of the cloud-ash composite buried hill based on the drilling data and 3D seismic data are as follows: Based on the drilling data, imaging logging interpretation is carried out to obtain the bottom formation dip of the cloud-ash composite buried hill; According to the formation dip angle of the cloud-ash composite buried hill bottom, the dip angle of seismic reflection event axis of the cloud-ash composite buried hill bottom is determined on 3D seismic data; According to the dip angle of seismic reflection event axis of the bottom surface of cloud-ash composite buried hill, the bottom surface of cloud-ash composite buried hill is interpreted on 3D seismic data; According to the results of the stratigraphic interpretation of the bottom of the cloud-ash composite buried hill, structural mapping is carried out to depict the bottom of the cloud-ash composite buried hill.

4. The cloud-ash composite buried hill characterization method according to claim 1, characterized in that: The specific steps of describing the dolomite buried hill boundary based on the three-dimensional seismic data and the dolomite-ash composite buried hill boundary are as follows: According to the three-dimensional seismic data and the characterization results of the cloud-ash composite buried hill top, the vertical time window is set at different lengths along the upper and lower sides of the cloud-ash composite buried hill top to extract the sensitive attributes of the fracture-vuggy reservoir; Calibrate a first threshold value for the sensitive attribute of the fracture-vuggy reservoir according to the drilling data; According to the first threshold value of the sensitive attribute of the fracture-vuggy reservoir, the range of dolomite is determined to obtain the attribute characterization result of the boundary of the dolomite buried hill; The intersection of the dolomite-ash composite buried-hill boundary characterization results and the dolomite buried-hill boundary attribute characterization results is taken to obtain the dolomite buried-hill boundary characterization results.

5. The cloud-ash composite buried hill characterization method according to claim 4, characterized in that: The sensitive attribute of the fracture-vuggy reservoir is a root mean square amplitude attribute.

6. The cloud-ash composite buried hill characterization method according to claim 5, characterized in that: The specific steps of calibrating the first threshold value of the sensitive attribute of the fracture-vuggy reservoir according to the drilling data are as follows: According to the drilling data, when the absolute value of the drilling time difference between two adjacent points in the reservoir is greater than the second threshold, the root mean square amplitude attribute value at the point where the drilling time becomes smaller is the first threshold.

7. The cloud-ash composite buried hill characterization method according to claim 6, characterized in that: The second threshold value ranges from 20 to 30 min / m.

8. A cloud-ash composite buried hill characterization device, characterized in that: include: The top surface unit is used to characterize the top surface of the cloud-ash composite buried mountain based on the well acoustic data and 3D seismic data; A bottom surface unit is used to describe the bottom surface of the cloud-ash composite buried hill based on the drilling data and the three-dimensional seismic data; An intersection unit is used to take the intersection of the cloud-ash composite buried hill top and the cloud-ash composite buried hill bottom to obtain a cloud-ash composite buried hill boundary; The boundary unit is used to characterize the dolomite buried hill boundary based on the three-dimensional seismic data and the dolomite-ash composite buried hill boundary.

9. The cloud-ash composite buried hill characterization device according to claim 8, characterized in that: The top surface unit is specifically used for: Use the acoustic data from the wells to create synthetic seismic records; The synthetic seismic record is calibrated with the three-dimensional seismic data to determine the seismic reflection event axis corresponding to the top of the cloud-ash composite buried hill; Based on the seismic reflection phase axis, the surface layer of the cloud-ash composite buried hill is interpreted on the three-dimensional seismic data; According to the results of the stratigraphic interpretation of the cloud-ash composite buried-mountain top, structural mapping is carried out to depict the cloud-ash composite buried-mountain top.

10. The cloud-ash composite buried hill characterization device according to claim 8, characterized in that: The bottom surface unit is specifically used for: Based on the drilling data, imaging logging interpretation is carried out to obtain the bottom formation dip of the cloud-ash composite buried hill; According to the formation dip angle of the cloud-ash composite buried hill bottom, the dip angle of seismic reflection event axis of the cloud-ash composite buried hill bottom is determined on 3D seismic data; According to the dip angle of seismic reflection event axis of the bottom surface of cloud-ash composite buried hill, the bottom surface of cloud-ash composite buried hill is interpreted on 3D seismic data; According to the results of the stratigraphic interpretation of the bottom of the cloud-ash composite buried hill, structural mapping is carried out to depict the bottom of the cloud-ash composite buried hill.

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