Carbonate formation planar sedimentary facies identification method based on seismic geologic attributes

Abstract

The application discloses a carbonate rock stratum plane sedimentary facies identification method based on seismic geological attributes, belongs to the technical field of sedimentary facies identification, and comprises the following steps: obtaining a two-way time window range of waveform classification of a target layer, then obtaining waveform classification data of the target layer, and reassigning the waveform classification data according to a sedimentary facies favorable principle to obtain new waveform classification data; calculating a two-way time thickness of the target layer; point-multiplying the new waveform classification data and the two-way time thickness of the target layer to obtain a sedimentary facies index, and performing plane display of the sedimentary facies index as a horizon in a system. The method for quantitatively determining a waveform classification attribute analysis time window on the basis of horizon interpretation is realized, the sedimentary facies index is obtained by performing numerical transformation processing on the waveform classification attribute and then point-multiplying the two-way time thickness of the target layer at the same position, and the rationality of conversion from a seismic facies to a sedimentary facies in the prior method is improved.

Description

Technical Field

[0001] This invention relates to the field of sedimentary facies identification technology, and in particular to a method for identifying planar sedimentary facies in carbonate rock strata based on seismic geological properties. Background Technology

[0002] Sedimentary facies are crucial factors controlling carbonate reservoir development and hydrocarbon accumulation; therefore, sedimentary facies identification is essential for discovering carbonate oil and gas reservoirs. Existing planar sedimentary facies identification methods largely rely solely on planar seismic attributes (primarily waveform classification attributes) or planar stratigraphic thickness variation analysis. However, the selection of the two-way time window significantly impacts planar seismic attribute characteristics. Extracting the same seismic attributes from different time windows can yield completely different planar seismic attribute characteristics. Furthermore, the selection of existing two-way time windows is often subjective and lacks quantitative quantification. Additionally, while stratigraphic thickness variations contain a wealth of information about sedimentary facies zone changes—for example, thick reef-shoal facies deposits often have significant stratigraphic thickness, while intershoal and cloud flat deposits are often thinner—the acquisition, processing, and stitching of seismic data can influence the identification of sedimentary facies in some areas, even with rapid stratigraphic thickness variations. Further exploration of planar stratigraphic thickness variation information and comprehensive analysis with planar waveform classification seismic attributes are necessary for a more reasonable identification of sedimentary facies in a region. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing sedimentary facies plane identification methods, which mostly rely solely on planar seismic attribute analysis or planar changes in stratigraphic thickness, resulting in low rationality of sedimentary facies identification. This invention provides a planar sedimentary facies identification method for carbonate strata based on seismic geological attributes.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] A method for identifying planar sedimentary facies in carbonate strata based on seismic geological attributes includes the following steps:

[0006] S1: Obtain the two-way time window range of the target layer waveform classification, then obtain the waveform classification data of the target layer, and reassign the waveform classification data according to the principle of favorable deposition phase zone to obtain new waveform classification data;

[0007] S2: Calculate the two-way time thickness of the target layer;

[0008] S3: Multiply the new waveform classification data by the two-way time thickness of the target layer to obtain the sedimentary facies index, and display the sedimentary facies index as the layer in the system in a plane.

[0009] By adopting the above technical solution, a method for quantitatively determining the time window for waveform classification attribute analysis based on stratigraphic interpretation is realized. By performing numerical transformation processing on the waveform classification attributes and then multiplying them by the two-way time thickness of the target layer at the same location, the sedimentary facies index is obtained, which improves the rationality of the conversion from seismic facies to sedimentary facies in existing methods.

[0010] As a preferred embodiment of the present invention, the two-way time window range of the target layer in step S1 is [C1, C1 + ΔT], where C1 is the existing bottom boundary two-way time value of the target layer, ΔT is the difference in the two-way time window, and the formula for calculating the difference in the two-way time window is:

[0011] ΔT = INT((Δt1 + Δt2) / 20) · 10

[0012] Δt1=MIN(C3)

[0013] Δt2=MAX(C3)

[0014]

[0015] Wherein, Δt1 is the minimum two-way time to the target layer, Δt2 is the maximum two-way time to the target layer, INT is the logarithmic value rounded to the tens digit, C1 is the existing two-way time value of the bottom boundary of the target layer, C2 is the existing two-way time value of the top boundary of the target layer, C3 is the two-way time difference between the bottom and top boundaries of the target layer with the same planar coordinates, MIN is the minimum logarithmic value, and MAX is the maximum logarithmic value.

[0016] As a preferred embodiment of the present invention, the principle of favorable depositional facies in step S1 is as follows: the waveform classification data of the target layer are reassigned sequentially from favorable to unfavorable, as expressed in the following expression:

[0017]

[0018] Where W1 is the waveform classification value of each point on the original plane, and W2 is the new waveform classification value of each point on the plane after reassignment.

[0019] As a preferred embodiment of the present invention, the formula for calculating the top boundary two-way travel time in step S2 is as follows:

[0020] C3 = C1 - C2

[0021] Wherein, C1 is the existing bottom boundary two-way time value of the target layer, C2 is the existing top boundary two-way time value of the target layer, and C3 is the two-way time thickness of the target layer with the same planar coordinates.

[0022] As a preferred embodiment of the present invention, the formula for calculating the depositional phase index in step S3 is as follows:

[0023] S = W²·C³

[0024]

[0025] Where W2 is the waveform classification value of each point on the plane after reassignment, S is the sedimentary facies index, and sn is the sedimentary facies index value of the nth point on the plane.

[0026] On the other hand, an electronic device is also disclosed, including at least one processor and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, which are executed by the at least one processor to enable the at least one processor to perform the planar sedimentary facies identification method for carbonate rock strata based on seismic geological properties as described above.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: it realizes a method for quantitatively determining the time window of waveform classification attribute analysis based on stratigraphic interpretation. By performing numerical transformation processing on the waveform classification attribute and then multiplying it by the two-way time thickness of the target layer at the same location, the sedimentary facies index is obtained, which improves the rationality of the conversion from seismic facies to sedimentary facies in the existing method. Attached Figure Description

[0028] Figure 1 This is a flowchart of a method for identifying planar sedimentary facies of carbonate strata based on seismic geological attributes, as described in Embodiment 1 of the present invention.

[0029] Figure 2 This is a waveform classification seismic attribute planar map of a planar sedimentary facies identification method for carbonate rock strata based on seismic geological attributes, as described in Embodiment 1 of the present invention.

[0030] Figure 3 This is a two-way time thickness map of the target layer in the planar sedimentary facies identification method for carbonate strata based on seismic geological attributes described in Embodiment 1 of the present invention.

[0031] Figure 4 This is a sedimentary facies index planar diagram of a planar sedimentary facies identification method for carbonate rock strata based on seismic geological attributes, as described in Embodiment 1 of the present invention.

[0032] Figure 5 This is a structural block diagram of an electronic device according to Embodiment 2 of the present invention. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to experimental examples and specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0034] Example 1

[0035] A method for identifying planar sedimentary facies in carbonate strata based on seismic geological attributes, such as... Figure 1 As shown, it includes the following steps:

[0036] S1: Obtain the two-way time window range of the target layer waveform classification, then obtain the waveform classification data of the target layer, and reassign the waveform classification data according to the principle of favorable deposition phase zone to obtain new waveform classification data;

[0037] S2: Calculate the two-way time thickness of the target layer;

[0038] S3: Multiply the new waveform classification data by the two-way time thickness of the target layer to obtain the sedimentary facies index, and display the sedimentary facies index as the layer in the system in a plane.

[0039] Specifically, such as Figure 2 , Figure 3 and Figure 4 As shown, Figure 2 The strata in area 1 are relatively thick, but Figure 3 The waveform classification attributes of region 1 in the image indicate an unfavorable sedimentary facies zone; Figure 3 Central region 2 shows a favorable sedimentary facies zone, but Figure 2 The strata in the central region 2 are relatively thin; Figure 4 (The darker the color, the greater the sedimentary facies index, which in turn indicates a more favorable sedimentary facies.) After adjustment, the sedimentary facies transition in Region 3 is more reasonable, which better solves the seemingly contradictory problem between waveform classification and stratigraphic thickness, laying the foundation for sedimentary geological analysis in this area.

[0040] In step S1, the two-way time window range of the target layer is [C1, C1 + ΔT], where C1 is the existing bottom boundary two-way time value of the target layer, and ΔT is the difference in the two-way time window. The formula for calculating the difference in the two-way time window is as follows:

[0041] ΔT = INT((Δt1 + Δt2) / 20) · 10

[0042] Δt1=MIN(C3)

[0043] Δt2=MAX(C3)

[0044]

[0045] Wherein, Δt1 is the minimum two-way time of the target layer, Δt2 is the maximum two-way time of the target layer, INT is the logarithmic value rounded to the tens digit, and the unit is ms, C1 is the existing bottom boundary two-way time value of the target layer, C2 is the existing top boundary two-way time value of the target layer, C3 is the two-way time thickness of the target layer with the same planar coordinates, MIN is the minimum logarithmic value, and MAX is the maximum logarithmic value.

[0046] The principle for favorable depositional facies zones in step S1 is as follows: the waveform classification data of the target layer are reassigned sequentially from favorable to unfavorable, as expressed below:

[0047]

[0048] Where W1 is the waveform classification value of each point on the original plane, and W2 is the new waveform classification value of each point on the plane after reassignment.

[0049] The formula for calculating the two-way time thickness of the target layer in step S2 is as follows:

[0050] C3 = C1 - C2

[0051] Wherein, C1 is the existing bottom boundary two-way time value of the target layer, C2 is the existing top boundary two-way time value of the target layer, and C3 is the two-way time thickness of the target layer with the same planar coordinates.

[0052] The formula for calculating the sedimentary facies index in step S3 is as follows:

[0053] S = W²·C³

[0054]

[0055] Where W2 is the waveform classification value of each point on the plane after reassignment, S is the sedimentary facies index, and sn is the sedimentary facies index value of the nth point on the plane.

[0056] By adopting the above technical solution, a method for quantitatively determining the time window for waveform classification attribute analysis based on stratigraphic interpretation is realized. By performing numerical transformation processing on the waveform classification attributes and then multiplying them by the two-way time thickness of the target layer at the same location, the sedimentary facies index is obtained, which improves the rationality of the conversion from seismic facies to sedimentary facies in existing methods.

[0057] Example 2

[0058] like Figure 5As shown, an electronic device includes at least one processor, a memory communicatively connected to the at least one processor, and at least one input / output interface communicatively connected to the at least one processor. The memory stores instructions executable by the at least one processor, which, when executed, enable the at least one processor to perform a planar sedimentary facies identification method for carbonate strata based on seismic geological attributes as described in the foregoing embodiments. The input / output interface may include a display, keyboard, mouse, and USB interface for inputting and outputting data.

[0059] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0060] When the integrated units of this invention are implemented as software functional units and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this invention, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for identifying planar sedimentary facies of carbonate strata based on seismic geological attributes, characterized in that, Includes the following steps: S1: Obtain the two-way time window range of the target layer waveform classification, then obtain the waveform classification data of the target layer, and reassign the waveform classification data according to the principle of favorable deposition phase zone to obtain new waveform classification data; The principle for favorable depositional facies zones in step S1 is as follows: the waveform classification data of the target layer are reassigned sequentially from favorable to unfavorable, as expressed below: Where W1 is the waveform classification value of each point in the original plane, and W2 is the new waveform classification value of each point in the plane after reassignment; S2: Calculate the two-way time thickness of the target layer; The formula for calculating the two-way time thickness of the target layer in step S2 is as follows: C3=C1 C2 Wherein, C1 is the existing two-way time value of the bottom boundary of the target layer, C2 is the existing two-way time value of the top boundary of the target layer, and C3 is the two-way time thickness of the bottom and top boundaries of the target layer with the same planar coordinates. S3: Multiply the new waveform classification data by the target layer two-way time thickness to obtain the sedimentary facies index, and display the sedimentary facies index as the layer in the system in a plane; The formula for calculating the sedimentary facies index in step S3 is as follows: S = W²·C³ Where W2 is the waveform classification value of each point on the plane after reassignment, S is the sedimentary facies index, and sn is the sedimentary facies index value of the nth point on the plane.

2. The method for identifying planar sedimentary facies of carbonate strata based on seismic geological attributes according to claim 1, characterized in that, In step S1, the two-way time window range of the target layer is [C1, C1 + ΔT], where C1 is the existing bottom boundary two-way time value of the target layer, and ΔT is the difference in the two-way time window. The formula for calculating the difference in the two-way time window is as follows: ΔT = INT((Δt1 + Δt2) / 20) · 10 Δt1=MIN(C3) Δt2=MAX(C3) Wherein, Δt1 is the minimum two-way time thickness of the target layer, Δt2 is the maximum two-way time thickness of the target layer, INT is the logarithmic value rounded to the tens digit, C1 is the existing two-way time value of the bottom boundary of the target layer, C2 is the existing two-way time value of the top boundary of the target layer, C3 is the two-way time thickness of the bottom and top boundaries of the target layer with the same planar coordinates, MIN is the minimum logarithmic value, and MAX is the maximum logarithmic value.

3. An electronic device, characterized in that, The method includes at least one processor and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, enable the at least one processor to perform the planar sedimentary facies identification method for carbonate strata based on seismic geological properties as described in any one of claims 1 to 2.

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