Method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs

Abstract

This invention relates to the field of oil and gas extraction and discloses a method for determining target intervals suitable for hydraulic fracturing from tight conglomerate reservoirs. The method includes: acquiring stratigraphic and rock information of the tight conglomerate reservoir in the target area; classifying the tight conglomerate reservoir into multiple conglomerate types based on the stratigraphic and rock information; generating geological feature results corresponding to each conglomerate type based on the stratigraphic and rock information; and selecting the optimal conglomerate type from the multiple conglomerate types based on the geological feature results. The method provided by this invention can screen out the most suitable conglomerate type for hydraulic fracturing from multiple conglomerate types, achieving accurate prediction and screening of the most suitable conglomerate type for hydraulic fracturing.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction, and more particularly to a method for identifying target sections in tight conglomerate reservoirs that are favorable for hydraulic fracturing. Background Technology

[0002] With the growth in energy demand and the continuous development of oil and gas prediction and development technologies, conglomerate oil and gas reservoirs have gradually become a new area of ​​oil and gas exploration. Tight conglomerate reservoirs belong to the category of unconventional reservoirs, and their low porosity and ultra-low permeability make hydraulic fracturing technology the only economically feasible production method.

[0003] However, current geological research on tight conglomerate reservoirs mainly focuses on oil and gas exploration, lacking research on engineering and oil and gas production. In engineering operations, the lack of fundamental geological theory makes it difficult to select favorable fracturing intervals and blocks during oil and gas extraction. This often leads to difficulties in controlling the propagation morphology and manner of fractures after hydraulic fracturing, resulting in poor fracture conductivity, low oil and gas extraction efficiency, and an inability to meet the demands of oil and gas production. Summary of the Invention

[0004] This invention provides a method for identifying target sections in tight conglomerate reservoirs that are favorable for hydraulic fracturing, in order to solve the above-mentioned problems.

[0005] In a first aspect, embodiments of the present invention provide a method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs. The method includes: acquiring stratigraphic and rock information of tight conglomerate reservoirs in the target area; classifying the tight conglomerate reservoirs into multiple conglomerate types based on the stratigraphic and rock information; generating geological feature results corresponding to each conglomerate type based on the stratigraphic and rock information; and selecting the optimal conglomerate type from the multiple conglomerate types based on the geological feature results.

[0006] The method provided in this invention can classify tight conglomerate reservoirs into various conglomerate types based on the stratigraphic rock information of the tight conglomerate reservoirs, and select the optimal conglomerate type most suitable for hydraulic fracturing from among the various conglomerate types, thereby achieving accurate prediction and selection of the optimal conglomerate type most suitable for hydraulic fracturing.

[0007] Optionally, the steps for obtaining stratigraphic rock information of tight conglomerate reservoirs in the target area include: measuring and analyzing at least one rock sample from the tight conglomerate reservoir to obtain the gravel size and gravel support morphology of the rock sample; scanning at least one rock sample from the tight conglomerate reservoir to obtain the gravel cementation degree and gravel composition of the rock sample; and combining the gravel size, gravel support morphology, gravel cementation degree, and gravel composition of the rock sample to obtain stratigraphic rock information.

[0008] Optionally, the stratigraphic rock information also includes color and structural information of the rock samples. Based on the stratigraphic rock information, the steps of classifying tight conglomerate reservoirs into multiple conglomerate types include: obtaining color and structural information of at least one rock sample, the structural information including the gravel shape, bedding structure, and gravel arrangement of the rock sample; determining the sedimentary subfacies of the rock sample based on the color and structural information; and classifying the tight conglomerate reservoir into an above-water category and a subsea category based on the sedimentary subfacies.

[0009] Optionally, after the step of classifying tight conglomerate reservoirs into above-water and below-water categories based on sedimentary subfacies, the method further includes: classifying tight conglomerate reservoirs belonging to the above-water category into four above-water subcategories and tight conglomerate reservoirs belonging to the below-water category into four below-water subcategories based on gravel size, gravel support morphology, gravel cementation degree, and gravel composition.

[0010] Optionally, the gravel size includes fine-grained, medium-grained, coarse-grained, and coarse-grained grades; the gravel support morphology includes mudstone support, sandstone support, and gravel support; the gravel cementation degree includes matrix content and cement content, with matrix content classified as low and high, and cement content classified as low and high; the gravel composition includes clastic rocks, metamorphic rocks, volcanic rocks, and mudstone; at least one of the following is different between the four underwater subclasses and between the four above-water subclasses: gravel size, gravel support morphology, gravel cementation degree, and gravel composition.

[0011] Optionally, the step of selecting the optimal conglomerate type from multiple conglomerate types based on geological characteristics includes: selecting conglomerate types from all underwater and above-water subgroups with fine and / or medium-sized gravel, gravel support morphology of sandstone support, low matrix content, high cement content, and single gravel composition, and selecting these as the optimal conglomerate type.

[0012] Optionally, the step of generating geological feature results corresponding to each conglomerate type based on stratigraphic rock information includes: obtaining rock samples of each tight conglomerate reservoir corresponding to each conglomerate type and stratigraphic rock information of each rock sample; generating geological feature results corresponding to each conglomerate type based on the stratigraphic rock information of each rock sample, wherein the geological feature results include gravel size, gravel support morphology, gravel cementation degree, and gravel composition of the tight conglomerate reservoir corresponding to each conglomerate type.

[0013] In a second aspect, embodiments of the present invention provide a method for oil and gas extraction from tight conglomerate reservoirs. The method includes: obtaining the optimal conglomerate type of any of the foregoing embodiments of the first aspect of the present invention; and, based on the optimal conglomerate type, performing hydraulic fracturing on a target rock layer in a target area corresponding to the optimal conglomerate type to extract oil and gas from the target area.

[0014] The oil and gas extraction method for tight conglomerate reservoirs provided in this invention improves the efficiency of oil and gas extraction by obtaining the optimal conglomerate type in any of the aforementioned embodiments of the first aspect of this invention, so that the fractures generated during hydraulic fracturing of the layers and blocks corresponding to the optimal conglomerate type have the strongest conductivity.

[0015] Thirdly, embodiments of the present invention provide a tight conglomerate reservoir classification and evaluation device, which includes a processor and a memory, wherein the memory stores instructions; the processor can call the instructions in the memory to cause the tight conglomerate reservoir classification and evaluation device to execute the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to any of the foregoing embodiments of the first aspect of the present invention, and the oil and gas extraction method for tight conglomerate reservoirs according to any of the foregoing embodiments of the second aspect of the present invention.

[0016] The processor of the tight conglomerate reservoir classification and evaluation device provided in this embodiment of the invention executes the method for determining target segments favorable for hydraulic fracturing from tight conglomerate reservoirs according to any of the aforementioned embodiments of the first aspect of the invention by calling instructions in the memory. Based on the stratigraphic and rock information of the tight conglomerate reservoir, the device can classify the reservoir into multiple conglomerate types and select the optimal conglomerate type most suitable for hydraulic fracturing from among these types, achieving accurate prediction and selection of the optimal conglomerate type most suitable for hydraulic fracturing. Furthermore, by executing the oil and gas extraction method for tight conglomerate reservoirs according to any of the aforementioned embodiments of the second aspect of the invention, the tight conglomerate reservoir classification and evaluation device can obtain the optimal conglomerate type from any of the aforementioned embodiments of the first aspect of the invention, ensuring that the fractures generated during hydraulic fracturing of the segments and blocks corresponding to the optimal conglomerate type have the strongest conductivity, thereby improving the efficiency of oil and gas extraction.

[0017] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing instructions that, when executed by a processor, implement the method for determining a target section favorable for hydraulic fracturing from a tight conglomerate reservoir according to any of the foregoing embodiments of the first aspect of the present invention, and the oil and gas extraction method from a tight conglomerate reservoir according to any of the foregoing embodiments of the second aspect of the present invention.

[0018] The instructions stored in the computer-readable storage medium provided in this invention can be invoked by a processor and executed by any of the aforementioned embodiments of the first aspect of this invention, namely, the method for determining target segments favorable for hydraulic fracturing from tight conglomerate reservoirs. When the storage medium is invoked by the processor, it can classify the tight conglomerate reservoir into multiple conglomerate types based on the formation and rock information of the reservoir, and select the optimal conglomerate type most suitable for hydraulic fracturing from among these types, thereby achieving accurate prediction and selection of the optimal conglomerate type most suitable for hydraulic fracturing. Furthermore, by executing the oil and gas extraction method for tight conglomerate reservoirs according to any of the aforementioned embodiments of the second aspect of this invention, it can obtain the optimal conglomerate type of any of the aforementioned embodiments of the first aspect of this invention, ensuring that the fractures generated during hydraulic fracturing of the segments and blocks corresponding to the optimal conglomerate type have the strongest conductivity, thereby improving the efficiency of oil and gas extraction. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0020] Figure 1 A flowchart illustrating one embodiment of the method of the present invention for identifying target sections favorable for hydraulic fracturing from tight conglomerate reservoirs;

[0021] Figure 2 This is a flowchart of step S110 in one embodiment of the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to the present invention;

[0022] Figure 3 This is a flowchart of step S120 in one embodiment of the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to the present invention;

[0023] Figure 4 This is a flowchart of step S130 in one embodiment of the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to the present invention;

[0024] Figure 5 This is a schematic diagram of different conglomerate types in one embodiment of the method of the present invention for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs;

[0025] Figure 6 This is a schematic diagram of lithofacies information for the first subsea subclass in one embodiment of the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to the present invention.

[0026] Figure 7 This is a schematic diagram of lithofacies information for the second sub-class in one embodiment of the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to the present invention.

[0027] Figure 8 This is a schematic diagram of lithofacies information of the third sub-class in one embodiment of the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to the present invention.

[0028] Figure 9 This is a schematic diagram of lithofacies information for the fourth sub-class in one embodiment of the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to the present invention.

[0029] Figure 10 This is a schematic diagram of lithofacies information for the first subclass of water in one embodiment of the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to the present invention.

[0030] Figure 11 This is a schematic diagram of lithofacies information for the second subclass of water in one embodiment of the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to the present invention.

[0031] Figure 12 This is a schematic diagram of lithofacies information for the third subclass of water in one embodiment of the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to the present invention.

[0032] Figure 13 This is a schematic diagram of lithofacies information for the fourth subclass of water in one embodiment of the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to the present invention.

[0033] Figure 14 This is a schematic diagram of lithofacies testing results for different conglomerate types in one embodiment of the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to the present invention.

[0034] Figure 15 A flowchart illustrating one embodiment of the oil and gas extraction method for tight conglomerate reservoirs according to the present invention;

[0035] Figure 16 This is a structural block diagram of one embodiment of the tight conglomerate reservoir classification and evaluation equipment of the present invention. Detailed Implementation

[0036] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] It should be noted that all directional indications in the embodiments of the present invention, such as up, down, left, right, front, back, etc., are only used to explain the relative positional relationship and movement of the components in a specific posture as shown in the attached figure. If the specific posture changes, the directional indication will also change accordingly.

[0038] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0039] This invention proposes a method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs, which is used to screen the optimal conglomerate type corresponding to the target interval from tight conglomerate reservoirs in the target area.

[0040] For ease of understanding, the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to embodiments of the present invention is described below, such as... Figure 1 As shown, the method for determining the target interval favorable for hydraulic fracturing from a tight conglomerate reservoir in this embodiment of the invention includes steps S110 to S140.

[0041] In step S110, the stratigraphic rock information of the tight conglomerate reservoir in the target area is obtained.

[0042] like Figure 2 As shown, in some optional embodiments, step S110 includes steps S111 to S113.

[0043] In step S111, at least one rock sample from the tight conglomerate reservoir is measured and analyzed to obtain the gravel size and gravel support morphology of the rock sample.

[0044] In step S112, at least one rock sample from the tight conglomerate reservoir is scanned to obtain the degree of gravel cementation and gravel composition of the rock sample.

[0045] In step S113, the gravel size, gravel support morphology, gravel cementation degree, and gravel composition of the rock sample are combined to obtain the stratigraphic rock information.

[0046] In this embodiment, multiple rock samples from different depths and layers of the tight conglomerate reservoir in the target area are acquired, and each rock sample is measured and analyzed. For example, the gravel size of the rock sample is measured, and the gravel support morphology of each rock sample is analyzed through X-ray diffraction. Simultaneously, each rock sample is scanned using a scanning electron microscope to obtain the degree of gravel cementation and gravel composition of each rock sample. Ultimately, stratigraphic rock information of different layers of the tight conglomerate reservoir is obtained for subsequent classification of different layers of the tight conglomerate reservoir.

[0047] In step S120, based on the stratigraphic rock information, the tight conglomerate reservoir is divided into multiple conglomerate types.

[0048] like Figure 3 As shown, in some optional embodiments, the stratigraphic rock information also includes color information and structural information of the rock samples. Step S120 includes steps S121 to S123.

[0049] In step S121, color information and structural information of at least one rock sample are obtained. The structural information includes the gravel shape, bedding structure, and gravel arrangement of the rock sample.

[0050] In step S122, the sedimentary subfacies of the rock sample is determined based on color and structural information.

[0051] In step S123, based on sedimentary subfacies, the tight conglomerate reservoir is divided into an above-water category and a subsea category.

[0052] In this embodiment, by using multiple rock samples from different layers at different depths in the tight conglomerate reservoir of the target area, it is also possible to obtain the color and structural information of the gravel in different layers of the tight conglomerate reservoir, thereby determining the gravel shape, bedding structure and gravel arrangement in different layers of the tight conglomerate reservoir. For example, the gravel shape includes sub-angular and sub-rounded, and the gravel arrangement includes debris flow, clastic flow and traction flow.

[0053] Color information for gravel includes oxidized and reduced colors. For example, oxidized colors include brown, such as dark brown, grayish brown, reddish brown, purple, and brownish gray; reduced colors include gray, such as greenish gray, brownish gray, dark gray, grayish green, and light grayish green.

[0054] By analyzing the color and structural information of gravels from different layers of the tight conglomerate reservoir, the sedimentary subfacies of each rock sample can be determined. The tight conglomerate reservoir can then be divided into an above-water category and a subsea category. The above-water category consists of strata located in the delta plain region, while the subsea category consists of strata located in the delta front region.

[0055] Furthermore, after step S123, step S120 also includes step S124.

[0056] In step S124, based on gravel size, gravel support morphology, gravel cementation degree, and gravel composition, tight conglomerate reservoirs belonging to the above-water category are divided into four above-water subcategories, and tight conglomerate reservoirs belonging to the underwater category are divided into four underwater subcategories.

[0057] In this embodiment, after determining the stratigraphic segments of the above-water major and minor categories in the tight conglomerate reservoir, each rock sample in the above-water major and minor categories is further classified according to the gravel size, gravel support morphology, gravel cementation degree, and gravel composition in the stratigraphic rock information, resulting in four corresponding above-water minor categories and four corresponding underwater minor categories.

[0058] Furthermore, the gravel size includes fine-grained, medium-grained, coarse-grained, and coarse-grained grades; the gravel support morphology includes mudstone support, sandstone support, and gravel support; the gravel cementation degree includes the content of matrix and the content of cementing material, with the matrix content divided into low and high content, and the cementing material content divided into low and high content; and the gravel composition includes clastic rocks, metamorphic rocks, volcanic rocks, and mudstone.

[0059] At least one of the following is different between the four underwater subclasses and between the four surface subclasses: gravel size, gravel support morphology, gravel cementation, and gravel composition.

[0060] Among them, the fine particles have a particle size of 2mm-8mm, the medium particles have a particle size of 8mm-32mm, the coarse particles have a particle size of 32mm-128mm, and the giant particles have a particle size greater than 128mm.

[0061] Clastic rocks include tuff, metamorphic rocks include quartzite and metamorphic sandstone, and volcanic rocks include felsite, granite and andesite.

[0062] Specifically, the four water-based subcategories in this embodiment of the invention include a first water-based subcategorie, a second water-based subcategorie, a third water-based subcategorie, and a fourth water-based subcategorie.

[0063] The gravel size of the first subclass of water is medium to fine, the gravel composition is clastic rock and granite, the gravel support morphology is gravel support, and the gravel cementation degree is low in both matrix and cement content.

[0064] The second subclass of marine gravel has a medium to coarse grain size, and the gravel composition is clastic rock and mudstone. The gravel support morphology is gravel support, and the gravel cementation degree is low in both matrix and cement content.

[0065] The gravel size of the third subgroup of water is coarse to giant, the gravel composition is clastic rock, the gravel support morphology is gravel support, and the gravel cementation degree is low in both matrix and cement content.

[0066] The gravel size of the fourth subcategory of marine rocks is medium to coarse, the gravel composition is clastic rock, the gravel support is mudstone support, and the gravel cementation is characterized by high matrix content and low cement content.

[0067] The four underwater subclasses in this embodiment of the invention include a first underwater subclass, a second underwater subclass, a third underwater subclass, and a fourth underwater subclass.

[0068] The gravel size of the first underwater subgroup ranges from coarse to giant. The gravel composition consists of clastic rocks, metamorphic rocks, and volcanic rocks. The gravel support morphology is gravel support. The gravel cementation degree is low matrix content and high cement content.

[0069] The second underwater subgroup has a gravel size ranging from medium to coarse, and the gravel composition consists of clastic rocks and volcanic rocks. The gravel support morphology is matrix support, and the gravel cementation degree is characterized by high matrix content and low cement content.

[0070] The gravel size of the third underwater subgroup is fine to medium, the gravel composition is clastic rock, the gravel support is sandstone support, and the gravel cementation is low matrix content and high cement content.

[0071] The fourth subgroup of underwater rocks is fine to medium-grained, with gravel composed of clastic rocks. The gravel support morphology is granular support, and the gravel cementation degree is characterized by low matrix and cement content.

[0072] In step S130, based on the stratigraphic rock information, geological feature results corresponding to each type of conglomerate are generated.

[0073] like Figure 4 As shown, in some optional embodiments, step S130 includes steps S131 to S132.

[0074] In step S131, rock samples of each type of conglomerate reservoir and stratigraphic rock information of each rock sample are obtained.

[0075] In step S132, based on the stratigraphic rock information of each rock sample, geological feature results corresponding to each conglomerate type are generated. These geological feature results include the gravel size, gravel support morphology, gravel cementation degree, and gravel composition of the tight conglomerate reservoir corresponding to each conglomerate type.

[0076] In this embodiment, after determining the above-water or underwater subclass corresponding to each rock sample, the corresponding stratigraphic segment is determined from the tight conglomerate reservoir based on the gravel size, gravel support morphology, gravel cementation degree, gravel composition, and the location of each rock sample in the tight conglomerate reservoir, so as to obtain the conglomerate type of the gravel segment. That is, the conglomerate type of the gravel segment is the conglomerate type of the corresponding rock sample.

[0077] Therefore, the tight conglomerate reservoir in this embodiment includes above-water major sections and below-water major sections. The above-water major sections include the first above-water minor section, the second above-water minor section, the third above-water minor section, and the fourth above-water minor section. The below-water major sections include the first below-water minor section, the second below-water minor section, the third below-water minor section, and the fourth below-water minor section. This achieves the goal of dividing the tight conglomerate reservoir into different sections based on the geological structure and gravel composition at different depths, so as to facilitate the selection of the most suitable section for hydraulic fracturing.

[0078] In step S140, based on the geological characteristics, the optimal conglomerate type is selected from a variety of conglomerate types.

[0079] In some optional embodiments, the specific steps for selecting the optimal conglomerate type from multiple conglomerate types based on geological characteristics are as follows: based on geological characteristics, select conglomerate types from all underwater and above-water subclasses with fine and / or medium-sized gravel, gravel support morphology of sandstone support, low matrix content, high cement content, and single gravel composition, and select these as the optimal conglomerate type.

[0080] In this embodiment, after dividing the tight conglomerate reservoir into four above-water sub-seamless segments and four below-water sub-seamless segments, the most suitable segment for hydraulic fracturing is selected based on the geological characteristics of the corresponding segments. That is, the segment corresponding to the conglomerate type with fine and / or medium-grained gravel, sandstone support, low matrix content, high cement content, and single gravel composition has the best physical properties and the largest thickness of the test layer, which is conducive to hydraulic fracturing.

[0081] The method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs provided in this invention includes: acquiring stratigraphic and rock information of tight conglomerate reservoirs in the target area; classifying the tight conglomerate reservoirs into multiple conglomerate types based on the stratigraphic and rock information; generating geological feature results corresponding to each conglomerate type based on the stratigraphic and rock information; and selecting the optimal conglomerate type from the multiple conglomerate types based on the geological feature results.

[0082] The method provided in this invention can classify tight conglomerate reservoirs into various conglomerate types based on the stratigraphic rock information of the tight conglomerate reservoirs, and select the optimal conglomerate type most suitable for hydraulic fracturing from among the various conglomerate types, thereby achieving accurate prediction and selection of the optimal conglomerate type most suitable for hydraulic fracturing.

[0083] like Figures 5 to 14 As shown, the present invention provides an embodiment of a method for determining target segments favorable for hydraulic fracturing from tight conglomerate reservoirs. The method classifies tight conglomerate reservoirs to determine target segments favorable for hydraulic fracturing. The specific process and results are shown below.

[0084] In this embodiment, the target stratigraphic intervals favorable for hydraulic fracturing were determined from the tight conglomerate reservoir of the Baikouquan Formation in the Mahu Depression of the Junggar Basin. Table 1 shows the lithofacies structure and composition characteristics of different conglomerate types in the tight conglomerate reservoir.

[0085]

[0086] Table 1

[0087] In this embodiment of the invention, by obtaining 600 rock samples from tight conglomerate reservoirs, the lithofacies structure and compositional characteristics of different conglomerate types in tight conglomerate reservoirs are obtained.

[0088] As shown in Table 1 and Figure 5 As shown, A represents the underwater category, A1 is the first underwater subcategory, A2 is the second underwater subcategory, A3 is the third underwater subcategory, and A4 is the fourth underwater subcategory; B represents the surface category, B1 is the first surface subcategory, B2 is the second surface subcategory, B3 is the third surface subcategory, and B4 is the fourth surface subcategory.

[0089] The method for determining target segments favorable for hydraulic fracturing in tight conglomerate reservoirs provided by the embodiments of the present invention determines the sedimentary subfacies of each segment based on the color and structural information of each segment of the tight conglomerate reservoir, thereby classifying the tight conglomerate reservoir into subsea and above-water categories.

[0090] Specifically, the underwater conglomerate is predominantly reduced in color, mainly including greenish-gray, brownish-gray, dark gray, gray, grayish-green, and light grayish-green. The structural information of the underwater conglomerate includes the shape of the gravel within each layer, its bedding structure, and the arrangement of the gravel. The gravel shapes are subangular to subrounded and subrounded; the gravel support forms include mudstone support, sandstone support, and gravel support; and the gravel arrangement patterns are debris flow and traction flow.

[0091] The conglomerate of the shoal group is predominantly oxidized in color, mainly including dark brown, grayish-brown, brown, reddish-brown, purple, brownish-gray, and other mixed colors. The structural information of the shoal group includes the shape, bedding structure, and arrangement of the gravel within its strata. The gravel shapes are subangular and subangular-subrounded, primarily massive. The gravel support is mainly mudstone and sandstone, and the arrangement patterns include debris flow, traction flow, and clastic flow.

[0092] like Figure 6 As shown, in the conglomerate section corresponding to the first underwater subclass, namely section A1, the lithofacies of section A1 are mainly metamorphic and volcanic rocks, with a gravel-supported morphology. The gravel grain size ranges from coarse to large. The lithofacies of section A1 are thick-bedded and massive, with a maximum thickness of 3m. The gravel color is mainly gray and greenish-gray. The bedding structure exhibits a positive rhythm, and the gravel arrangement shows graded bedding and weakly oriented arrangement.

[0093] The first underwater sub-stratum, A1, consists of thin, interbedded layers of gravelly sandstone or dark mudstone, ranging from 10cm to 30cm in thickness, with scour surfaces between the sandstone / mudstone and the gravel. The gravel at the bottom of sub-stratum A1 is larger, reaching the giant grain size, and the gravel supports each other, exhibiting a massive structure. The gravel near the upper part of sub-stratum A1 becomes finer in size. The overall rounded shape of the gravel is subangular to sub-rounded and sub-rounded.

[0094] The average gravel content in the first underwater sub-group A1 is 69.93%. The gravel components are mainly clastic rocks (tuff), metamorphic rocks (metamorphosed sandstone and quartzite), and volcanic rocks (felphyllite and andesite), accounting for 32.36%, 38.5%, and 28.95%, respectively. The matrix is ​​composed of argillaceous matrix, and the average content of the matrix is ​​relatively low, at 1.98%. The cement is composed of calcite, and the average content of the cement is relatively high, at 5.95%.

[0095] The porosity of the first underwater sub-layer A1 is 7%-14%, and the permeability is (0.15-5)×10-3μm. 2 Its physical properties are relatively poor.

[0096] like Figure 7As shown, in the conglomerate section corresponding to the second subsea subclass, namely section A2, the lithofacies of section A2 are mainly clastic and volcanic rocks, supported by mudstone, with gravel grain size ranging from medium to coarse. The lithofacies of section A2 are thick-bedded and massive, with a maximum thickness of 2-3 m. The gravel color mainly includes gray, such as brownish-gray and earthy gray. The bedding structure is massive and rhythmic, and the gravel arrangement is oriented.

[0097] The second underwater sub-section A2 consists of thin layers of interbedded gravelly sandstone or dark mudstone, ranging from 10cm to 30cm in thickness, with scour-fill structures between the sandstone or mudstone and the gravel. The overall roundness of the gravel is moderately good, and the overall rounded shape of the gravel is subangular to sub-rounded and sub-rounded.

[0098] The average gravel content in the second underwater sub-group A2 is 58.79%. The gravel composition is mainly composed of clastic rocks (tuff) and volcanic rocks (felphyserite and andesite), accounting for 43.32% and 32.78% respectively; mudstone is the second most abundant component, accounting for 16.74%. Compared with the first underwater sub-group A1, the metamorphic rock content in the gravel composition is lower, while the mudstone content is higher. The matrix in the second underwater sub-group A2 includes argillaceous material, kaolinite, and chlorite, with a relatively high average matrix content of 7.78%. The cement is composed of calcite and iron-bearing calcite, with a relatively low average cement content of 0.62%.

[0099] The porosity histogram of the second underwater sub-stratum A2 shows a unimodal pattern, with porosity values ​​ranging from 6% to 9%. The permeability exhibits a low unimodal pattern with a wide variation range, ranging from (0.16 to 10) × 10⁻³ μm. 2 Compared to the first underwater sub-category A1, the second underwater sub-category A2 has worse physical properties.

[0100] like Figure 8 As shown, in the conglomerate section corresponding to the third subsea subclass, namely section A3, the lithofacies of section A3 is mainly clastic rock, with sandstone support. The gravel grain size is medium to fine-grained, i.e., sandstone conglomerate. The gravel color mainly includes gray, such as greenish-gray, brownish-gray, and dark brownish-gray. The bedding structure is massive, with positive and negative rhythms, and the gravel arrangement is weakly oriented. The lithofacies of section A3 are interbedded with gravelly sandstone, coarse sandstone, or dark mudstone. There are obvious scour and infill structures between different lithologies. Parallel bedding and trough cross-bedding are present in the coarse sandstone. The rounding varies greatly, with the overall rounded shape of the gravel being subangular, subangular-subrounded, and subrounded.

[0101] The average gravel content of the third underwater sub-group A3 is 45.7%, with clastic rocks (tuff) being the main component, accounting for 51.42%; volcanic rocks (granite and andesite) are the secondary component, accounting for 28.4%; sedimentary rocks (mudstone and siliceous rocks) and metamorphic rocks (metamorphosed sandstone and quartzite) have relatively low contents, accounting for 9.06% and 11.14%, respectively. The matrix consists of hydromica, kaolinite, chlorite, and argillaceous material, with a relatively low average matrix content of 2.53%; the cement consists of calcite and iron-bearing calcite, with a relatively high average cement content of 5.61%.

[0102] The porosity and permeability histograms of the third subsea sub-sequence A3 both show a unimodal pattern, with reservoir porosity ranging from 8% to 14% and permeability of (0.32-5) × 10⁻³ μm. 2 Compared with the first subsea sub-section A1 and the second subsea sub-section A2, the third subsea sub-section A3 has better lithofacies reservoir properties.

[0103] like Figure 9 As shown, in the conglomerate section corresponding to the fourth subsea subclass, specifically section A4, the lithofacies of section A4 are dominated by clastic rocks, supported by gravel, with gravel grain sizes ranging from medium to fine. The maximum thickness of the lithofacies in section A4 can reach 2m. The gravel colors mainly include gray, such as purplish-gray, brownish-gray, greenish-gray, and dark gray. The bedding structures are massive, rhythmic, anti-rhythmic, and scour-filled, and the gravel arrangement shows a weakly oriented arrangement.

[0104] The lithofacies of the fourth underwater sub-section A4 are interbedded with gravelly sandstone, coarse sandstone or mudstone. There are obvious scour and filling structures between different lithologies. The overall rounded shape of the gravel is subangular and subangular-subrounded.

[0105] The average gravel content of the fourth subsea subgroup A4 is 75.16%, with clastic rocks (tuff) dominating at 63.56%, followed by volcanic rocks (granite and andesite) at 25.6%, sedimentary rocks (mudstone and siliceous rocks) at a low level of 9.79%, and metamorphic rocks at a very low level of 1.02%. Unlike the third subsea subgroup A3, the metamorphic rock content in the fourth subsea subgroup A4 is extremely low, almost zero. The matrix of the fourth subsea subgroup A4 includes hydromica, kaolinite, chlorite, and argillaceous material, with a low average matrix content of 3.29%; the cement includes calcite and iron-bearing calcite, with a low average cement content of 0.33%.

[0106] The porosity histogram of the fourth underwater sub-segment A4 is unimodal, with a porosity value of 6-8%. The permeability histogram is bimodal, with a large variation range, and a permeability value of 0.08-200×10-3μm2.

[0107] like Figure 10 As shown, in the conglomerate section corresponding to the first subclass of navigable rock, specifically section B1, the lithofacies of section B1 are mainly clastic and volcanic rocks, supported by gravel with a medium to fine grain size. The maximum thickness of the lithofacies in section B1 can reach 4m. The gravel colors are mainly purplish-red and brown, the bedding structure is massive, the gravel arrangement is weakly oriented, and there are scour-fill structures and abrupt lithological changes.

[0108] The lithofacies of the first sub-aquatic section B1 are interbedded with 10cm-30cm thick brown mudstone, with abrupt changes between different lithologies. The overall rounded shape of the gravel is subangular and subangular-subrounded.

[0109] The average gravel content of the first sub-group B1 is 77.6%, with clastic rocks (tuff) dominating at 71.26%, followed by volcanic rocks (granite) at 21.22%, and sedimentary rocks (mudstone) at a relatively low content of 7.52%. The matrix of the first sub-group B1 includes biotite, kaolinite, chlorite, and ferruginous mudstone, with a relatively low average matrix content of 2.7%. The cementing component is magnetite, with a relatively low average cementing content of 0.63%.

[0110] The porosity histogram of the first aquatic sub-segment B1 shows a unimodal pattern, with porosity values ​​ranging from 6% to 9%. The permeability histogram also shows a high unimodal pattern, with permeability values ​​ranging from 0.32 to 2.5 × 10⁻³ μm. 2 This means that the reservoir porosity of the first sub-category B1 is low, but the permeability is high.

[0111] like Figure 11 As shown, in the conglomerate section corresponding to the second subclass of navigable sedimentary rocks, specifically section B2, the lithofacies of section B2 are dominated by clastic and sedimentary rocks, supported by gravel with a medium to coarse grain size. The maximum thickness of the lithofacies in section B2 can reach 6m, and the gravel color is mainly brown. The bedding structure is massive, with positive and negative gravel rhythms, and the gravel arrangement is oriented.

[0112] The lithofacies of the second sub-group B2 are interbedded with 20cm-50cm of dark medium-coarse sandstone and gravelly mudstone, with scour-fill structures and abrupt changes between different lithologies. The overall rounded shape of the gravel is subangular and subangular-subrounded.

[0113] The average gravel content of the second sub-group B2 is 76.4%, with clastic rocks (tuff) dominating (72.43%), followed by sedimentary rocks (18.2%), and volcanic rocks (5.1%). The matrix of the second sub-group B2 includes hydromica, argillaceous material, and ferruginous argillaceous material, with a low average content of 2.4%. The cementing material includes ferruginous mud and argillaceous material, with a low average content of 1.07%.

[0114] The porosity histogram of the second sub-aquatic layer B2 shows a high unimodal pattern, with porosity values ​​of 6%-8%. The permeability histogram also shows a high unimodal pattern, with permeability values ​​ranging from 0.04 to 1.25 × 10⁻³ μm. 2 This means that the reservoir porosity and permeability of the second sub-aquatic layer B2 are both low.

[0115] like Figure 12 As shown, in the conglomerate section corresponding to the third subclass of navigable rock, specifically section B3 of the third subclass, the lithofacies of section B3 is dominated by clastic rocks, supported by gravel, with gravel grain sizes ranging from coarse to large. The maximum thickness of the lithofacies in section B3 of the third subclass of navigable rock can reach 10m. The gravel colors mainly include brown, such as reddish-brown, grayish-brown, and greenish-brown. The lithofacies of section B3 of the third subclass of navigable rock exhibit a massive structure, with bedding exhibiting both positive and negative rhythms, and the gravel arrangement showing a weakly oriented arrangement.

[0116] The lithofacies of the third sub-group B3 consist of 20-50 cm thick layers of dark, gravelly coarse sandstone and dark mudstone thicker than 1 m, with scour-fill structures and abrupt changes between different lithologies. The rounding of the gravel in the third sub-group B3 is moderate, with the overall rounding shape of the gravel being subangular to subrounded and subrounded.

[0117] The average gravel content of the third sub-group B3 is 72.2%, with clastic rocks (tuff) dominating at 74.2%; volcanic rocks (felite, rhyolite, andesite, and granite) are secondary at 19.41%; metamorphic rocks (metamorphosed sandstone and quartzite) are relatively low at 5.65%; no sedimentary rocks are present. The matrix consists of hydrous muscovite, kaolinite, argillaceous material, and ferruginous argillaceous material, with a low average content of 2.8%; the cement consists of calcite, with an extremely low average content of 0.07%.

[0118] The porosity histogram of the third sub-aquatic layer B3 shows a unimodal pattern, with porosity values ​​ranging from 6% to 8%. The permeability histogram shows a short unimodal pattern with a wide variation range, with permeability values ​​ranging from 0.04 to 2.5 × 10⁻³ μm. 2 The third sub-category of the water column, B3, has low porosity but slightly higher permeability.

[0119] like Figure 13 As shown, in the conglomerate section corresponding to the fourth subclass of navigable rock, specifically section B4, the fourth subclass of navigable rock section B4 is dominated by clastic, volcanic, and sedimentary rocks, supported by mudstone. The gravel grain size is medium to coarse-grained. The maximum thickness of the lithofacies in section B4 of the fourth subclass of navigable rock can reach 5m. The gravel color mainly includes brown, such as reddish-brown, dark brown, and brownish-gray. The bedding structure and gravel arrangement are massive and graded bedding, respectively.

[0120] The fourth sub-group B4 contains 10-30 cm of dark mudstone, with scour-fill structures and abrupt lithological changes between different lithologies. The rounding of the gravel in the fourth sub-group B4 varies considerably, with the overall rounded shape of the gravel being subangular, subangular-subrounded, and subrounded.

[0121] The average gravel content of the fourth sub-group B4 is 52.3%, with clastic rocks (tuff) dominating (61.64%), followed by volcanic rocks (felite and granite) (20.42%), and sedimentary rocks accounting for a relatively low 6.28%. The matrix of the fourth sub-group B4 includes hydromica, hydromica-derived argillaceous material, kaolinite, chlorite, and iron oxide-derived argillaceous material, with a high average matrix content of 11.24%. The cementing components include calcite and analcime, with a low average cementing content of 1.24%. The porosity histogram of the fourth sub-group B4 shows a high unimodal pattern (6-9%), while the permeability histogram shows a high bimodal pattern (0.32-0.64×10⁻³ μm² and 1.25-5×10⁻³ μm², respectively). 2 The fourth sub-aquatic layer, B4, has low porosity but high permeability.

[0122] As shown above, the third underwater sub-stratum A3 is the target stratum that best matches the optimal conglomerate type.

[0123] like Figure 14 As shown, after dividing the tight conglomerate reservoir into different conglomerate types and obtaining the lithofacies information of the conglomerate intervals corresponding to each conglomerate type, oil testing experiments were conducted on the conglomerate intervals corresponding to each conglomerate type to obtain the lithofacies oil testing results of the conglomerate intervals corresponding to each conglomerate type.

[0124] Based on the lithofacies testing results of different conglomerate types, it can be determined that the conglomerate intervals corresponding to the subsea major categories have better testing results, with larger cumulative thicknesses of oil-bearing and oil-producing layers. In contrast, the conglomerate intervals corresponding to the surface major categories have poorer testing results, mainly consisting of water-bearing and dry layers. Among the subsea major categories, the conglomerate intervals corresponding to the third subsea subcategory have the best lithofacies testing results, with a cumulative oil layer thickness reaching 100m. Furthermore, the conglomerate intervals corresponding to the third subsea subcategory are conducive to the formation of tension fractures during hydraulic fracturing. Although the cumulative oil layer thicknesses of the conglomerate intervals corresponding to the first, second, and fourth subsea subcategories are also considerable, the cumulative thicknesses of water-bearing and dry layers are still relatively large. Therefore, it can be determined that the conglomerate intervals corresponding to the third subsea subcategory are the most favorable lithofacies type for hydraulic fracturing, i.e., the third subsea subcategory is the optimal conglomerate type.

[0125] like Figure 15 As shown, the present invention also proposes a method for oil and gas extraction from tight conglomerate reservoirs, which is used to hydraulically fracture the target rock formation according to the optimal conglomerate type of any of the foregoing embodiments of the present invention.

[0126] The method for oil and gas extraction from tight conglomerate reservoirs provided in this embodiment of the invention includes steps S210 to S220.

[0127] In step S210, the optimal conglomerate type of any of the foregoing embodiments of the present invention is obtained.

[0128] In step S220, based on the optimal conglomerate type, hydraulic fracturing is performed on the target rock strata corresponding to the optimal conglomerate type located in the target area to collect oil and gas in the target area.

[0129] In this embodiment, by obtaining the optimal conglomerate type of any of the aforementioned embodiments of the present invention, a target rock layer corresponding to the optimal conglomerate type is found in the target area, and hydraulic fracturing is performed on the target rock layer to make the fracture generated by hydraulic fracturing have the strongest conductivity, ensuring that hydraulic fracturing can be used for the most suitable rock layer, ensuring the fracturing effect each time hydraulic fracturing is performed, realizing the control of the expansion morphology of the fracture in the rock layer after hydraulic fracturing, avoiding the inconsistent morphology of the fracture generated after each hydraulic fracturing, and ensuring the stability and high efficiency of oil and gas extraction.

[0130] The oil and gas extraction method for tight conglomerate reservoirs provided in this invention improves the efficiency of oil and gas extraction by obtaining the optimal conglomerate type in any of the aforementioned embodiments of the first aspect of this invention, so that the fractures generated during hydraulic fracturing of the layers and blocks corresponding to the optimal conglomerate type have the strongest conductivity.

[0131] In addition to the above method embodiments, the present invention also provides, for example, Figure 16The device shown is a tight conglomerate reservoir classification and evaluation device, including: processor 201 and memory 202, wherein the memory 202 stores instructions.

[0132] The processor 201 can call instructions in the memory 202 to cause the tight conglomerate reservoir classification and evaluation device to execute the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to any of the foregoing embodiments of the present invention, as well as the oil and gas extraction method for tight conglomerate reservoirs according to any of the foregoing embodiments of the present invention.

[0133] Methods for identifying target intervals favorable for hydraulic fracturing in tight conglomerate reservoirs include: obtaining stratigraphic and lithographic information of the tight conglomerate reservoir in the target area; classifying the tight conglomerate reservoir into multiple conglomerate types based on the stratigraphic and lithographic information; generating geological feature results corresponding to each conglomerate type based on the stratigraphic and lithographic information; and selecting the optimal conglomerate type from the multiple conglomerate types based on the geological feature results.

[0134] The method for oil and gas extraction from tight conglomerate reservoirs includes: obtaining the optimal conglomerate type according to any of the foregoing embodiments of the present invention; and, based on the optimal conglomerate type, performing hydraulic fracturing on the target rock layer corresponding to the optimal conglomerate type in the target area to extract oil and gas from the target area.

[0135] The tight conglomerate reservoir classification and evaluation equipment provided in this embodiment of the invention, by implementing the above-described method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs, can classify tight conglomerate reservoirs into various conglomerate types based on the formation and rock information of the tight conglomerate reservoirs, and select the optimal conglomerate type most suitable for hydraulic fracturing from among the various conglomerate types. This achieves accurate prediction and screening of the optimal conglomerate type most suitable for hydraulic fracturing. Furthermore, by executing the oil and gas extraction method for tight conglomerate reservoirs in any of the aforementioned embodiments of the invention, the tight conglomerate reservoir classification and evaluation equipment provided in this embodiment of the invention can obtain the optimal conglomerate type in any of the aforementioned embodiments of the invention, so that when hydraulic fracturing is performed on the intervals and blocks corresponding to the optimal conglomerate type, the fractures generated have the strongest conductivity, thereby improving the efficiency of oil and gas extraction.

[0136] Furthermore, the tight conglomerate reservoir classification and evaluation device provided in this embodiment of the invention may also include a communication interface 203 and a bus 204, with the processor 201, memory 202 and communication interface 203 electrically connected via the bus 204.

[0137] The memory 202 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface 203 (which can be wired or wireless), such as the Internet, wide area network, local area network, or metropolitan area network. The bus 204 can be an ISA bus, PCI bus, or EISA bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 16 The symbol is represented by a single double-headed arrow, but this does not mean that there is only one bus or one type of bus.

[0138] Processor 201 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of processor 201 or by instructions in software form. The processor 201 can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software module can reside in a mature storage medium in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory 202. The processor 201 reads the information in memory 202 and, in conjunction with its hardware, completes the steps of the method described in the foregoing embodiments.

[0139] This invention also provides a computer-readable storage medium, which can be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium. The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the steps of the above-described method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs and the above-described method for oil and gas extraction from tight conglomerate reservoirs.

[0140] The computer-readable storage medium provided in this embodiment of the invention stores data and computer-executable instructions for the method of determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs and the oil and gas extraction method of tight conglomerate reservoirs.

[0141] The above-mentioned method for determining the target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs includes: obtaining stratigraphic and rock information of tight conglomerate reservoirs in the target area; classifying tight conglomerate reservoirs into multiple conglomerate types based on the stratigraphic and rock information; generating geological feature results corresponding to each conglomerate type based on the stratigraphic and rock information; and selecting the optimal conglomerate type from multiple conglomerate types based on the geological feature results.

[0142] The above-mentioned method for oil and gas extraction from tight conglomerate reservoirs includes: obtaining the optimal conglomerate type according to any of the preceding embodiments of the present invention; and, based on the optimal conglomerate type, performing hydraulic fracturing on the target rock strata corresponding to the optimal conglomerate type located in the target area to extract oil and gas from the target area.

[0143] The instructions stored in the computer-readable storage medium provided in this invention can be called by a processor and executed according to any of the foregoing embodiments of the method for determining target segments favorable for hydraulic fracturing from tight conglomerate reservoirs. When the storage medium is called by the processor, it can classify the tight conglomerate reservoir into multiple conglomerate types based on the formation rock information of the tight conglomerate reservoir, and select the optimal conglomerate type most suitable for hydraulic fracturing from among the multiple conglomerate types, thereby achieving accurate prediction and selection of the optimal conglomerate type most suitable for hydraulic fracturing; and by executing the oil and gas extraction method for tight conglomerate reservoirs according to any of the foregoing embodiments of the invention, it can obtain the optimal conglomerate type according to any of the foregoing embodiments of the invention, so that when hydraulic fracturing is performed on the segments and blocks corresponding to the optimal conglomerate type, the fracture conductivity is the strongest, thereby improving the efficiency of oil and gas extraction.

[0144] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0145] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, 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 steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0146] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for identifying target intervals favorable for hydraulic fracturing in tight conglomerate reservoirs, characterized in that, The method includes: Obtain stratigraphic and lithographic information of tight conglomerate reservoirs in the target area; Based on the stratigraphic and rock information, the tight conglomerate reservoir is classified into several conglomerate types; Based on the stratigraphic and rock information, geological feature results corresponding to each type of conglomerate are generated; Based on the geological characteristics, the optimal conglomerate type was selected from a variety of conglomerate types.

2. The method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to claim 1, characterized in that, The steps for obtaining the stratigraphic and rock information of the tight conglomerate reservoir in the target area include: At least one rock sample from the tight conglomerate reservoir was measured and analyzed to obtain the gravel size and gravel support morphology of the rock sample. At least one rock sample from the tight conglomerate reservoir is scanned to obtain the degree of gravel cementation and gravel composition of the rock sample; The stratigraphic rock information is obtained by combining the gravel size, gravel support morphology, gravel cementation degree, and gravel composition of the rock sample.

3. The method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to claim 2, characterized in that, The stratigraphic rock information also includes the color and structural information of the rock samples. The step of classifying the tight conglomerate reservoir into multiple conglomerate types based on the stratigraphic rock information includes: Obtain the color information and structural information of at least one of the rock samples, wherein the structural information includes the gravel shape, bedding structure, and gravel arrangement of the rock sample; Based on the color information and the structural information, the sedimentary subfacies of the rock sample is determined; Based on the aforementioned sedimentary subfacies, the tight conglomerate reservoir is divided into an above-water category and a subsea category.

4. The method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to claim 3, characterized in that, After the step of classifying the tight conglomerate reservoir into above-water and below-water categories based on the sedimentary subfacies, the method further includes: Based on the gravel size, gravel support morphology, gravel cementation degree, and gravel composition, the tight conglomerate reservoir belonging to the above-water category is divided into four above-water subcategories, and the tight conglomerate reservoir belonging to the underwater category is divided into four underwater subcategories.

5. The method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to claim 4, characterized in that, The gravel particle size includes fine-grained, medium-grained, coarse-grained, and coarse-grained sizes; the gravel support morphology includes mudstone support, sandstone support, and gravel support; the gravel cementation degree includes the content of matrix and the content of cementing material, with the matrix content divided into low and high content, and the cementing material content divided into low and high content; the gravel composition includes clastic rocks, metamorphic rocks, volcanic rocks, and mudstone. At least one of the following is different between the four underwater subclasses and between the four above-water subclasses: gravel size, gravel support morphology, gravel cementation, and gravel composition.

6. The method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to claim 5, characterized in that, The step of selecting the optimal conglomerate type from multiple conglomerate types based on the geological characteristics includes: Based on the geological characteristics, the optimal conglomerate type is selected from all the underwater and above-water subcategories, with gravel size of fine and / or medium, gravel support morphology of sandstone support, low matrix content, high cement content, and single gravel composition.

7. The method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs according to claim 2, characterized in that, The step of generating geological feature results corresponding to each type of conglomerate based on the stratigraphic rock information includes: Obtain the rock samples of each tight conglomerate reservoir corresponding to each type of conglomerate, as well as the stratigraphic rock information of each rock sample; Based on the stratigraphic rock information of each rock sample, geological feature results corresponding to each conglomerate type are generated. The geological feature results include the gravel size, gravel support morphology, gravel cementation degree, and gravel composition of the tight conglomerate reservoir corresponding to each conglomerate type.

8. A method for oil and gas extraction from tight conglomerate reservoirs, characterized in that, The method includes: Obtain the optimal conglomerate type as described in any one of claims 1 to 7; Based on the optimal conglomerate type, hydraulic fracturing is performed on the target rock strata corresponding to the optimal conglomerate type located in the target area to extract oil and gas from the target area.

9. A classification and evaluation device for tight conglomerate reservoirs, characterized in that, The tight conglomerate reservoir classification and evaluation device includes a processor and a memory, wherein the memory stores instructions. The processor can invoke the instructions in the memory to enable the tight conglomerate reservoir classification and evaluation device to implement the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs as described in any one of claims 1 to 7, and the oil and gas extraction method for tight conglomerate reservoirs as described in claim 8.

10. A computer-readable storage medium storing instructions thereon, characterized in that, When the instructions are executed by the processor, they implement the method for determining target intervals favorable for hydraulic fracturing from tight conglomerate reservoirs as described in any one of claims 1 to 7, and the oil and gas extraction method for tight conglomerate reservoirs as described in claim 8.

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