Method and device for determining cut type unconformity trap

Abstract

The invention discloses a method for determining a cutting type unconformity trap, which comprises the following steps of: determining a vertical structure of an unconformity surface according to well drilling and logging data of a target area; according to the vertical structure of the unconformity surface, determining an unconformity plane distribution diagram with oil and gas shielding capability, a target area unconformity surface structural diagram and a plane distribution diagram of a cut reservoir under the unconformity surface; and determining a cut type unconformity trap according to the unconformity plane distribution diagram, the target area unconformity surface structure diagram and the plane distribution diagram of the cut reservoir under the unconformity surface. According to the method, the effectiveness of the cut unconformity trap can be rapidly evaluated, and the exploration success rate is improved.

Description

Technical Field

[0001] This invention relates to the field of evaluating the effectiveness of traps, and in particular to a method and apparatus for determining cut-off unconformity traps. Background Technology

[0002] Stratigraphic unconformities are important stratigraphic interfaces, key objects for studying major events such as tectonic movements and sea-level rise and fall. They are also important locations for fluid migration, particularly hydrocarbon accumulation, holding significant importance in earth science and petroleum geology. Large stratigraphic unconformities often form "downward-cutting and upward-overlapping" stratigraphic structures, meaning the strata below the unconformity are cut off, while various overlapping structures form above it, such as upward-overlapping towards structural highs and downward-cutting towards structural lows. In such "downward-cutting and upward-overlapping" stratigraphic structures, traps often form due to the unconformity surface, known as unconformity traps.

[0003] Unconformity traps are crucial for large-scale hydrocarbon discoveries in continental basins and are also important targets for locating large-scale hydrocarbon resources. Exploration practice shows that stratigraphic unconformities are widely developed in basins, but not all unconformity surfaces can form effective unconformity traps. Therefore, identifying unconformity traps has become a pressing technical problem that needs to be solved. Summary of the Invention

[0004] The purpose of this invention is to provide a method and apparatus for determining cut-off unconformity traps, which can quickly evaluate the effectiveness of cut-off unconformity traps and improve the exploration success rate.

[0005] To achieve the above objectives, this invention provides a method for determining cut-off unconformity traps, comprising: determining the vertical structure of the unconformity surface based on drilling and logging data of the target area; determining, based on the vertical structure of the unconformity surface, an unconformity planar distribution map with oil and gas shielding capabilities, a structural map of the unconformity surface in the target area, and a planar distribution map of the cut-off reservoir beneath the unconformity surface; and determining the cut-off unconformity trap based on the unconformity planar distribution map, the structural map of the unconformity surface in the target area, and the planar distribution map of the cut-off reservoir beneath the unconformity surface. This method can rapidly evaluate the effectiveness of cut-off unconformity traps and improve the exploration success rate.

[0006] The present invention also provides a device for determining a cut-off type unconformity trap, comprising:

[0007] The first unit is used to determine the vertical structure of the unconformity surface based on drilling and logging data of the target area;

[0008] The second unit is used to determine, based on the vertical structure of the unconformity, the unconformity plane distribution map with oil and gas shielding capability, the unconformity plane structure map of the target area, and the plane distribution map of the cut-off reservoir below the unconformity.

[0009] The third unit is used to determine the cut-off unconformity trap based on the unconformity plane distribution map, the unconformity surface structure map of the target area, and the plane distribution map of the cut-off reservoir under the unconformity surface.

[0010] The present invention also provides an electronic device, comprising: a processor coupled to a memory;

[0011] The processor is configured to read and execute a computer program stored in the memory to implement the method described in any of the preceding embodiments.

[0012] The present invention also provides a computer-readable storage medium storing a program or instructions that, when executed by a processor, implement the method as described in any of the preceding claims.

[0013] The technical effects and advantages of this invention are as follows:

[0014] This invention provides a method for determining cut-off unconformity traps, comprising: determining the vertical structure of the unconformity surface based on drilling and logging data of the target area; determining, based on the vertical structure of the unconformity surface, an unconformity planar distribution map with oil and gas shielding capabilities, a structural map of the unconformity surface in the target area, and a planar distribution map of the cut-off reservoir beneath the unconformity surface; and determining the cut-off unconformity trap based on the unconformity planar distribution map, the structural map of the unconformity surface in the target area, and the planar distribution map of the cut-off reservoir beneath the unconformity surface. This method can quickly evaluate the effectiveness of cut-off unconformity traps and improve the exploration success rate.

[0015] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0016] Figure 1 A flowchart illustrating the method for determining truncated unconformity traps;

[0017] Figure 2 A diagram showing the unconformity structure of the central Junggar Basin.

[0018] Figure 3 Map showing the distribution of unconformity types in the central Junggar Basin;

[0019] Figure 4 The three images are overlaid to determine the closed loop of the cut-off unconformity. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0022] To facilitate a better understanding of this scheme, we will first briefly introduce the formation elements of unconformity traps. Unconformity traps are related to three factors: first, the structural characteristics of the unconformity surface and its ability to shield oil and gas; second, the morphology of the reservoir boundary extension in contact with the unconformity; and third, the structural diagram of the unconformity surface. By combining these three factors and overlaying them into a diagram, the effectiveness of the unconformity trap can be effectively evaluated. The following explanation will detail how to achieve the above.

[0023] A method for determining truncated unconformity traps, such as... Figure 1 As shown, it includes the following steps:

[0024] 1. Determine the vertical structure of the unconformity surface based on drilling and logging data of the target area.

[0025] Specifically, this includes: comprehensively utilizing the comprehensive logging profile data from drilling (including lithological logging and corresponding logging curves) to determine the vertical lithological sequence above and below the unconformity. Generally, a complete unconformity structure develops from bottom to top into four parts: the semi-weathered rock layer formed by the weathering of the lower strata, the weathered clay layer, the unconformity, and the upper rock layer. However, due to the influence of geological evolution, the unconformity structure in different regions may have one or both of the semi-weathered rock layer and the weathered clay layer missing, thus forming different unconformity structures.

[0026] 2. Based on the vertical structure of the unconformity, determine the unconformity planar distribution map with oil and gas shielding capability, the unconformity structure map of the target area, and the planar distribution map of the cut-off reservoir below the unconformity.

[0027] Specifically, this includes: 2.1 Determining the distribution map of unconformities with oil and gas shielding capabilities, including:

[0028] 2.1.1 Sampling analysis and well logging interpretation are performed on the rock layers (such as weathered clay layer, semi-weathered rock layer, and upper rock layer) in the vertical structure of the unconformity surface to determine the porosity and permeability of the rock layers;

[0029] 2.1.2 Based on the porosity and permeability of the rock layer, the type of unconformity structure with oil and gas blocking capability is determined. Specifically, based on the porosity and permeability of the rock layer obtained from drilling core and wellbore coring experiments, or the porosity and permeability of the rock layer obtained from well logging curves, when the porosity is less than 5% and the air permeability is ≤0.1mD, it can be determined as an unconformity structure with oil and gas blocking capability.

[0030] 2.1.3 Based on the unconformity structure type with oil and gas shielding capability, the seismic response characteristics of the unconformity surface are obtained;

[0031] 2.1.4 Based on the seismic response characteristics of the unconformity, determine the distribution map of the unconformity plane with oil and gas shielding capability.

[0032] 2.2 Determine the unconformity surface construction diagram of the target region, including:

[0033] Seismic interpretation software (such as Geoeast and Landmark) is used to automatically identify unconformities in the vertical structure of the unconformity surface, and a structural map of the unconformity surface in the target area is obtained by compiling it.

[0034] 2.3 Determine the planar distribution map of the truncated reservoir beneath the unconformity surface, including:

[0035] Using interpretation software such as Geoeast and Landmark, well-seismic calibration is performed on the top and bottom surfaces of the reservoir below the unconformity. By quickly interpreting the contact lines between the top and bottom surfaces of the reservoir and the unconformity, the planar distribution range of the cut-off reservoir below the unconformity is delineated, and a planar distribution map of the cut-off reservoir on the unconformity is then compiled.

[0036] 3. Based on the unconformity plane distribution map, the unconformity surface structure map of the target area, and the plane distribution map of the cut-off reservoir below the unconformity surface, determine the cut-off unconformity trap.

[0037] Specifically, this includes: overlaying the unconformity plane distribution map, the unconformity surface structure map of the target area, and the plane distribution map of the truncated reservoir under the unconformity surface to determine the overlapping area;

[0038] The overlapping region is defined as a cut-off unconformity loop.

[0039] To better explain the present invention, embodiments are also provided below.

[0040] This method was applied to the study of hydrocarbon accumulation on unconformities in the Jurassic strata of the central Junggar Basin and the Permian-Triassic strata of the western depression. The specific steps include:

[0041] (1) Determine the vertical structure of the unconformity surface

[0042] The vertical structure of the unconformity is determined using drilling and logging data from the target area. By comprehensively utilizing integrated drilling logging profile data (including lithological logging and corresponding logging curves), the vertical lithological sequence above and below the unconformity is determined. Generally, a complete unconformity structure develops from bottom to top into four parts: semi-weathered rock layers formed by the weathering of the lower strata, weathered clay layers, the unconformity itself, and the upper rock layers. However, due to geological evolution, the unconformity structure in different regions may lack one or both of the semi-weathered rock layers or weathered clay layers, resulting in different unconformity structures, such as... Figure 2 As shown. Among them, Figure 2 The types of nonintegration can be divided into four main categories: Type I, Type II1, Type II2, and Type III. Type II1 can be further subdivided into two subtypes: II... 1-1 Type II 1-2 Type II2 can be further divided into three subtypes, namely II 2-1 Type II 2-2 Type II 2-3 type.

[0043] (2) Determine the type of unconformity structure with oil and gas shielding capability.

[0044] After determining the vertical structure of the unconformity, the porosity and permeability of the weathered clay layer, semi-weathered rock layer and the upper rock layer are determined by sampling or well logging interpretation, and the unconformity structure with oil and gas shielding capability (Type I, Type II1) is identified.

[0045] (3) Determine the distribution map of unconformities with oil and gas shielding capabilities and compile unconformity surface structure maps.

[0046] Based on the reflection characteristics of unconformities that can block oil and gas in seismic data, the planar distribution of this type of unconformity is determined.

[0047] Seismic interpretation software such as Geoeast or Landmark is used to automatically identify unconformities in the vertical structure of the unconformity surface, and to quickly generate unconformity surface structure diagrams. Figure 3 ).in, Figure 3 This is a planar distribution map of unconformity types in a local area, where only types I1 and II are developed. 2-1 Type II2-2 Type II 2-3 Type 4 unconformity structures. Simultaneously, based on the automatic identification results of the unconformity surfaces, an unconformity surface construction diagram is quickly generated (e.g., Figure 4 (As shown by the contour lines in the image).

[0048] (4) Planar distribution of truncated reservoirs beneath the unconformity surface

[0049] By combining well and seismic analysis, the top and bottom interfaces of the target sand body under the unconformity can be quickly interpreted. By connecting the sand body with the cut-off point of the unconformity, the contact zone of the reservoir on the unconformity can be plotted, thereby quickly determining the planar distribution zone of the cut-off reservoir under the unconformity in contact with the unconformity, and then plotting the planar distribution map of the cut-off reservoir under the unconformity.

[0050] (5) Overlaying three images to quickly delineate and determine effective cut-off unconformity traps.

[0051] By overlaying the planar distribution map of the identified unconformity below the unconformity, the distribution map of the unconformity with oil and gas shielding capability, and the structural map of the unconformity, the area where the three overlap can form a trap according to the structural coil is an effective unconformity trap. Figure 4 ).

[0052] The present invention also provides a device for determining a cut-off type unconformity trap, comprising:

[0053] The first unit is used to determine the vertical structure of the unconformity surface based on drilling and logging data of the target area;

[0054] The second unit is used to determine, based on the vertical structure of the unconformity, the unconformity plane distribution map with oil and gas shielding capability, the unconformity plane structure map of the target area, and the plane distribution map of the cut-off reservoir below the unconformity.

[0055] The third unit is used to determine cut-off unconformity traps based on the unconformity plane distribution map, the unconformity surface structure map of the target area, and the plane distribution map of the cut-off reservoir below the unconformity surface.

[0056] Since the protection provided by this device is similar to that provided by the method described above, it will not be described in detail here. Please refer to the discussion section of the method described above for more information.

[0057] The present invention also provides a device. This electronic device includes: at least one processor, at least one communication interface, at least one memory, and at least one communication bus; optionally, the communication interface can be an interface of a communication module, such as an interface of a GSM module; the processor may be a CPU, an Application Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The memory may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device. The memory stores a program, and the processor calls the program stored in the memory to execute the methods provided in the above embodiments of this application.

[0058] Corresponding to the methods described above in this application, this application also provides a computer storage medium. The computer storage medium stores a computer program, which is executed by a processor to perform the methods provided in the above embodiments of this application.

[0059] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., 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 determining a truncated unconformity trap, characterized in that, include: Based on drilling and logging data in the target area, determine the vertical structure of the unconformity surface; Based on the vertical structure of the unconformity, determine the unconformity planar distribution map with oil and gas shielding capability, the unconformity structure map of the target area, and the planar distribution map of the cut-off reservoir below the unconformity. Based on the unconformity plane distribution map, the unconformity surface structure map of the target area, and the planar distribution map of the cut-off reservoir below the unconformity surface, the cut-off unconformity trap is determined.

2. The method for determining a cut-off unconformity trap according to claim 1, characterized in that, Based on the vertical structure of the unconformity surface, a distribution map of unconformities with oil and gas shielding capabilities is determined, including: Sampling analysis and well logging interpretation were performed on the rock layers in the vertical structure of the unconformity to determine the porosity and permeability of the rock layers; Based on the porosity and permeability of the rock layer, determine the type of unconformity structure with oil and gas blocking capability; Based on the unconformity structure type with oil and gas shielding capability, determine the unconformity planar distribution map with oil and gas shielding capability.

3. The method for determining the cut-off unconformity trap according to claim 2, characterized in that, Based on the aforementioned unconformity structure type with oil and gas shielding capability, determine the unconformity planar distribution map with oil and gas shielding capability, including: Based on the unconformity structure type with oil and gas shielding capability, the seismic response characteristics of the unconformity surface are obtained; Based on the seismic response characteristics of the unconformity, a distribution map of unconformities with oil and gas shielding capabilities is determined.

4. The method for determining a cut-off unconformity trap according to claim 1, characterized in that, Based on the vertical structure of the unconformity surface, determine the unconformity surface construction diagram of the target region, including: Seismic interpretation software was used to automatically identify unconformities in the vertical structure of the unconformity surface, and a structural map of the unconformity surface in the target area was obtained by compiling the map.

5. The method for determining a cut-off unconformity trap according to claim 1, characterized in that, Based on the vertical structure of the unconformity, determine the planar distribution map of the truncated reservoir below the unconformity, including: Based on the vertical structure of the unconformity, the planar distribution zone of the truncated reservoir below the unconformity is determined; The planar distribution zones of the truncated reservoirs under the unconformity surface are compiled to obtain a planar distribution map of the truncated reservoirs under the unconformity surface.

6. The method for determining a cut-off unconformity trap according to claim 1, characterized in that, Based on the unconformity plane distribution map, the unconformity surface structure map of the target area, and the planar distribution map of the cut-off reservoir below the unconformity surface, the cut-off unconformity traps are determined, including: The unconformity plane distribution map, the unconformity surface structure map of the target area, and the plane distribution map of the truncated reservoir under the unconformity surface are overlaid to determine the overlapping area; Based on the overlapping region, a cut-off unconformity trap is determined.

7. A device for determining a cut-off type unconformity trap, characterized in that, include: The first unit is used to determine the vertical structure of the unconformity surface based on drilling and logging data of the target area; The second unit is used to determine, based on the vertical structure of the unconformity, the unconformity plane distribution map with oil and gas shielding capability, the unconformity plane structure map of the target area, and the plane distribution map of the cut-off reservoir below the unconformity. The third unit is used to determine the cut-off unconformity trap based on the unconformity plane distribution map, the unconformity surface structure map of the target area, and the plane distribution map of the cut-off reservoir under the unconformity surface.

8. A device for determining a cut-off type unconformity trap, characterized in that, Based on the vertical structure of the unconformity surface, a distribution map of unconformities with oil and gas shielding capabilities is determined, including: Sampling analysis and well logging interpretation were performed on the rock layers in the vertical structure of the unconformity to determine the porosity and permeability of the rock layers; Based on the porosity and permeability of the rock layer, determine the type of unconformity structure with oil and gas blocking capability; Based on the unconformity structure type with oil and gas shielding capability, determine the unconformity planar distribution map with oil and gas shielding capability.

9. An electronic device, characterized in that, include: Processor, the processor being coupled to memory; The processor is configured to read and execute a computer program stored in the memory to implement the method as described in any one of claims 1-6.

10. A computer-readable storage medium storing a program or instructions, characterized in that, When the program or instructions are executed by the processor, they implement the method as described in any one of claims 1-6.

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