Quantitative characterization method for shale bedding development degree

Abstract

The invention discloses a shale bedding development degree quantitative characterization method which specifically comprises the following steps: step 1, acquiring a full-diameter shale core, and determining a bedding surface of the full-diameter shale core; step 2, processing the full-diameter shale core to obtain a plunger rock sample or a square rock sample, and marking a bedding direction for the plunger rock sample or the square rock sample; step 3, drying the plunger rock sample or the square rock sample; 4, measuring the size and weight of the plunger rock sample or the square rock sample, and measuring the longitudinal wave propagation time of sound waves in the plunger rock sample or the square rock sample through sound wave measuring equipment to obtain the longitudinal wave speed; and step 5, acquiring the development index of the rock core bedding based on the longitudinal wave velocity. The method can be widely applied to characterization of the rock bedding development degrees under different scales, and the judgment efficiency of the rock bedding development degrees is improved.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas exploration technology, specifically relating to a method for quantitative characterization of the degree of shale bedding development. Background Technology

[0002] Shale oil and gas resources have enormous potential. Shale oil and gas reservoirs are typical mudstone and shale formations. Their color, composition, structure, reservoir characteristics and oil content are highly heterogeneous and are mainly controlled by complex mineral composition and lithofacies.

[0003] Currently, shale oil and gas reservoirs are generally classified into three types based on the degree of bedding development, from weakest to strongest: interbedded, laminated, and pure shale. For a specific reservoir, it is generally believed that the more developed the bedding, the larger the reservoir space and the easier it is to fracturate and stimulate. Therefore, the degree of bedding development is an important indicator for evaluating shale oil and gas reservoirs.

[0004] Current technologies for evaluating the degree of bedding development mainly rely on core observation or counting the number of bedding fractures per unit length of rock in electrical imaging logging images. For example, the existing technology with publication number CN117974703A discloses a method for continuous identification of shale bedding structures based on whole-wellbore electrical imaging logging. This method standardizes the scale of whole-wellbore electrical imaging logging images, sets threshold scales for resistivity images of different formation structures, and then performs threshold segmentation on the entire well section image to achieve automatic identification and division of shale bedding structures. However, bedding fractures in the core have different levels; large ones are visible to the naked eye and may even be directly broken, while small ones are not visible to the naked eye and can only be seen under CT or electron microscopy. Due to the resolution limitations of electrical imaging logging, this method cannot identify smaller-scale fractures. The prior art disclosed in CN114624267A is an invention patent for identifying minerals and laminae in rock cores using dual-energy CT index scanning. The invention obtains CT slice images and absorption coefficients from high- and low-energy scanning of rock core samples, calculates the dual-energy CT index and establishes a relationship diagram between depth and the index, classifies minerals by inflection points, and identifies different minerals by the range from the boundary line to the peak and valley. At the same time, the invention delineates laminae, solving the problem of difficulty in distinguishing them with the naked eye and realizing mineral laminae identification and analysis.

[0005] The degree of development of rock bedding can also be reflected by changes in the physical properties of rocks, such as indirectly by using properties like rock resistivity, acoustic waves, density, and mechanical properties.

[0006] The aforementioned existing technologies can only analyze the development of rock bedding at specific scales. Shale exhibits significant differences in anisotropy at different scales, resulting in discrepancies in the analytical results of the different methods, which are not comparable. Summary of the Invention

[0007] The purpose of this invention is to provide a quantitative characterization method for the degree of shale bedding development, which can be widely applied to characterize the degree of rock bedding development at different scales, thereby improving the efficiency of judging the degree of rock bedding development.

[0008] The technical solution adopted in this invention is a method for quantitatively characterizing the degree of shale bedding development, which specifically includes the following steps: Step 1: Obtain a full-diameter shale core and determine the bedding planes of the full-diameter shale core; Step 2: Process the full-diameter shale core to obtain plunger or square rock samples, and mark the bedding direction on the plunger or square rock samples; Step 3: Dry the plunger rock sample or square rock sample; Step 4: First, measure the size and weight of the plunger rock sample or square rock sample, and then measure the longitudinal wave propagation time of the sound wave in the plunger rock sample or square rock sample using an acoustic wave measuring device to obtain the longitudinal wave velocity. Step 5: Obtain the development index of core bedding based on longitudinal wave velocity.

[0009] The invention is further characterized in that, In step 1, the bedding plane of the full-diameter shale core is determined as follows: if the full-diameter shale core contains straight bedding fractures or lithological variation surfaces, then the bedding fractures or lithological variation surfaces are taken as bedding planes. Otherwise, for relatively horizontal formations, the bedding plane of the core sample taken from a vertical well is perpendicular to the axis of the entire diameter core, the bedding plane of the core sample taken from a horizontal well is parallel to the axis of the entire diameter core, and the angle of the core sample taken from an inclined well is corrected based on the inclination data. For relatively inclined strata, the core axis is corrected based on the dip angle of the strata.

[0010] In step 2, when processing the full-diameter shale core into plunger samples, there should be at least one pair of plunger samples. The bedding direction of one plunger sample is marked as vertical bedding, and the bedding direction of the other plunger sample is marked as horizontal bedding.

[0011] The diameter of the plunger rock samples ranges from 2.5 cm to 3.8 cm, and the height ranges from 3 cm to 5 cm.

[0012] In step 2, when the full-diameter shale core is processed into a square rock sample, the bedding direction of the square rock sample is marked with both vertical bedding and horizontal bedding, and the vertical bedding and horizontal bedding are perpendicular to each other.

[0013] In step 3, drying specifically involves placing the processed plunger rock sample or square rock sample into an oven, drying at a temperature of 90℃~100℃ for 24 hours.

[0014] In step 4, the propagation time of the longitudinal wave in the plunger rock sample or square rock sample is measured using an acoustic wave measurement device, and the longitudinal wave velocity is obtained as shown in the following formula: ; In the formula, v is the longitudinal wave velocity, s is the propagation distance, and t is the propagation time.

[0015] In step 5, the development index of core bedding is obtained based on the P-wave velocity. When a full-diameter shale core is processed into a plunger sample, the core bedding development index is as follows: ; In the formula, The index of shale bedding development; V H The longitudinal wave velocity is the velocity parallel to the bedding direction in the plunger rock sample. V V The longitudinal wave velocity in the direction perpendicular to the bedding plane in the plunger rock sample; When a full-diameter shale core is processed into a square sample, the core bedding development index is shown in the following formula: ; ; In the formula, The index of shale bedding development; V K The average longitudinal wave velocity parallel to the bedding direction in the square rock sample; V Z The longitudinal wave velocity perpendicular to the bedding direction in the square rock sample; V X and V Y The values ​​represent the longitudinal wave velocities in different parallel bedding directions within a square rock sample.

[0016] The beneficial effects of this invention are: The present invention provides a quantitative characterization method for the development degree of shale bedding. This method utilizes the characteristic that the longitudinal wave velocity of rock is sensitive to the response of fractures. It quantitatively characterizes the shale bedding development index by using the ratio of the difference in sound velocity in the direction parallel to and perpendicular to the bedding to the longitudinal wave velocity in the direction parallel to the bedding. This allows the identification method to be applied to the identification of the development degree of rock bedding at any scale, without having to change different identification methods according to the size of the shale bedding fractures, thus improving the efficiency of judging the development degree of rock bedding. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the quantitative characterization method for the development degree of shale bedding according to the present invention. Figure 2 This is a schematic diagram of a plunger rock sample used in the quantitative characterization method for the development degree of shale bedding in this invention; Figure 3 This is a schematic diagram of a square rock sample used in the quantitative characterization method for the development of shale bedding in this invention. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] Experiments involving electrical, acoustic, and permeability measurements through core penetration are all affected by cracks within the rock. Experiments revealed that when cracks exist perpendicular to the penetration direction, core measurements of electrical conductivity, acoustic velocity, and permeability are significantly lower than those parallel to the crack direction. Among these three parameters, acoustic velocity reflects this difference most significantly.

[0020] Longitudinal waves (PWs) are compression waves, with the direction of particle vibration parallel to the direction of sound wave propagation. When a vertical crack appears in its propagation path, it's equivalent to the sound wave entering the air from within the mineral framework. The former's sound wave propagation speed is generally between 2000 m / s and 7000 m / s, while the latter is 340 m / s, a difference of about 10 times. The density difference is 3-4 orders of magnitude, resulting in a 4-5 order of magnitude difference in wave impedance (the product of velocity and density). Therefore, PWs experience significant attenuation when passing through a crack. However, when the crack is parallel to the PW propagation direction, its impact on PW propagation is minimal. The difference in PW velocity between perpendicular and parallel cracks depends on the size and number of cracks, as well as the sound wave propagation speed within the rock framework. The ratio of the difference in PW velocities between the two directions to the PW velocity in the direction parallel to the crack can reflect the development of cracks perpendicular to the sound wave propagation direction.

[0021] Shale cores possess inherent bedding properties. Upon reaching the surface, stress release typically causes the bedding planes to open, forming larger fractures. Bedding fractures are ubiquitous in shale cores, but they vary in size; some are visible to the naked eye, while others require an electron microscope to reveal the directional arrangement of minerals. Electron microscopes typically offer up to 105x magnification, and as mentioned earlier, P-wave velocity responds to fractures of this magnitude, thus characterizing the bedding development of shale.

[0022] Based on the above principles, the technical solution of the present invention is shown in the following embodiments.

[0023] Example 1 The present invention provides a quantitative characterization method for the degree of shale bedding development, such as... Figure 1 As shown, the specific steps include: Step 1: Obtain a full-diameter shale core and determine the bedding planes of the full-diameter shale core; Since experiments are conducted by sampling from the entire diameter core of the well, the first step is to determine the bedding plane of the entire diameter core. If there is a clear, straight bedding fracture or lithological change surface, then the bedding fracture or lithological change surface is taken as the bedding plane. If the bedding plane cannot be determined by visual inspection, it is determined according to the following principles: For horizontal formations, the bedding plane of the core taken from a vertical well is perpendicular to the axis of the entire diameter core, and the bedding plane of the core taken from a horizontal well is parallel to the axis of the entire diameter core. For deviated wells, the angle must be corrected based on the well inclination data. For inclined formations, the core axis is corrected to the angle of the formation dip.

[0024] Step 2: Process the full-diameter shale core to obtain plunger or square rock samples, and mark the bedding direction on the plunger or square rock samples; Step 3: Dry the plunger rock sample or square rock sample; Step 4: First, measure the size and weight of the plunger rock sample or square rock sample, and then measure the longitudinal wave propagation time of the sound wave in the plunger rock sample or square rock sample using an acoustic wave measuring device to obtain the longitudinal wave velocity. Specifically, acoustic measurement equipment typically includes an ultrasonic transducer, an ultrasonic detector, a coupling agent, a core holder, and an oscilloscope.

[0025] An ultrasonic transducer is a device that converts electrical energy into ultrasonic energy. When measuring ultrasonic longitudinal waves in a rock core, the transmitting transducer converts the electrical signal into an ultrasonic longitudinal wave signal, enabling it to propagate within the rock core; the receiving transducer then converts the received ultrasonic longitudinal wave signal back into an electrical signal for subsequent processing and analysis.

[0026] The ultrasonic testing instrument generates high-frequency electrical pulses to excite the ultrasonic transducer to emit ultrasonic longitudinal waves, and amplifies, processes, and displays the signals received by the receiving transducer. It can measure parameters such as the propagation time and amplitude of ultrasonic longitudinal waves in the core. Because ultrasonic longitudinal waves experience strong attenuation when propagating in air, a coupling agent needs to be applied between the core and the ultrasonic transducer to reduce reflection and scattering of ultrasonic energy at the interface, ensuring that ultrasonic longitudinal waves can effectively enter and exit the core.

[0027] An oscilloscope can display the electrical signal waveform of ultrasonic longitudinal waves. By observing the characteristics of the waveform, such as amplitude, frequency, and phase, one can intuitively understand the propagation of ultrasonic longitudinal waves in the rock core and further analyze and verify the measurement results.

[0028] Furthermore, the longitudinal wave velocity is obtained from the longitudinal wave propagation time, as shown in the following formula: ; In the formula, v is the longitudinal wave velocity, s is the propagation distance, and t is the propagation time.

[0029] Step 5: Obtain the development index of core bedding based on longitudinal wave velocity.

[0030] Example 2 Based on Example 1, the square rock sample in this example includes a cube or a cuboid.

[0031] Example 3 The present invention provides a quantitative characterization method for the degree of shale bedding development, which specifically includes the following steps: Step 1: Obtain a full-diameter shale core and determine the bedding planes of the full-diameter shale core; Since experiments are conducted by sampling from the entire diameter core of the well, the first step is to determine the bedding plane of the entire diameter core. If there is a clear, straight bedding fracture or lithological change surface, then the bedding fracture or lithological change surface is taken as the bedding plane. If the bedding plane cannot be determined by visual inspection, it is determined according to the following principles: For horizontal formations, the bedding plane of the core taken from a vertical well is perpendicular to the axis of the entire diameter core, and the bedding plane of the core taken from a horizontal well is parallel to the axis of the entire diameter core. For deviated wells, the angle must be corrected based on the well inclination data. For inclined formations, the core axis is corrected to the angle of the formation dip.

[0032] Step 2: Process the full-diameter shale core to obtain a plunger sample, and mark the bedding direction on the plunger sample; like Figure 2 As shown, in this embodiment, the full-diameter shale core is processed into a plunger sample in step 2, and there is at least one pair of plunger samples, with one plunger sample having a vertical bedding direction and the other plunger sample having a horizontal bedding direction.

[0033] Furthermore, the diameter of the plunger rock samples ranged from 2.5 cm to 3.8 cm, and the height ranged from 3 cm to 5 cm.

[0034] Step 3: Dry the processed plunger rock sample; Furthermore, before drying the plunger rock samples, they should not be washed with oil or salt. This method preserves the original state and characteristics of the shale to the greatest extent possible, allowing for a more accurate study of its physical, chemical, and mechanical properties under natural conditions. Removing oil and salt could alter the shale's pore structure, surface properties, and mechanical strength, thus affecting the understanding of its essential characteristics.

[0035] Step 4: First, measure the size and weight of the plunger rock sample, and then measure the longitudinal wave propagation time of the sound wave in the plunger rock sample using an acoustic wave measuring device to obtain the longitudinal wave velocity. Specifically, in this embodiment, the plunger rock samples are labeled with H for horizontal bedding and V for vertical bedding. The P-wave velocity of the horizontal bedding plunger rock sample is shown in the following formula: ; In the formula, The P-wave velocity of the horizontally bedding plunger sample. The height of the horizontally bedding plunger sample. The propagation time of the sound wave in the horizontally bedding plunger rock sample is given.

[0036] The P-wave velocity of a vertically bedding plunger sample is shown in the following formula: ; In the formula, The P-wave velocity of the vertically bedding plunger sample. The height of the plunger rock sample perpendicular to the bedding plane. The propagation time of the sound wave in the vertically bedding plunger rock sample is denoted as .

[0037] Step 5: Obtain the development index of core bedding based on longitudinal wave velocity.

[0038] Example 4 The present invention provides a quantitative characterization method for the degree of shale bedding development, which specifically includes the following steps: Step 1: Obtain a full-diameter shale core and determine the bedding planes of the full-diameter shale core; Since experiments are conducted by sampling from the entire diameter core of the well, the first step is to determine the bedding plane of the entire diameter core. If there is a clear, straight bedding fracture or lithological change surface, then the bedding fracture or lithological change surface is taken as the bedding plane. If the bedding plane cannot be determined by visual inspection, it is determined according to the following principles: For horizontal formations, the bedding plane of the core taken from a vertical well is perpendicular to the axis of the entire diameter core, and the bedding plane of the core taken from a horizontal well is parallel to the axis of the entire diameter core. For deviated wells, the angle must be corrected based on the well inclination data. For inclined formations, the core axis is corrected to the angle of the formation dip.

[0039] Step 2: Process the full-diameter shale core to obtain square rock samples, and mark the bedding directions on the square rock samples; like Figure 3 As shown, in this embodiment, the full-diameter shale core from step 2 is processed into a square rock sample, and the bedding direction of the square rock sample is marked with both vertical and horizontal bedding, which are perpendicular to each other. Arrows are drawn along the three sides at a vertex, labeled X, Y (parallel to bedding direction) and Z (perpendicular to bedding direction).

[0040] Step 3: Dry the processed square rock sample; Specifically, the processed square rock sample is placed in an oven and dried at a temperature of 90℃~100℃ for 24 hours.

[0041] Step 4: First, measure the size and weight of the square rock sample, and then measure the longitudinal wave propagation time of the sound wave in the square rock sample using an acoustic wave measuring device to obtain the longitudinal wave velocity. Specifically, in this embodiment, for the square rock sample, X and Y are used to mark the horizontal bedding of the square rock sample, and Z is used to mark the vertical bedding of the square rock sample. The P-wave velocity of the horizontal bedding in the square rock sample is shown in the following formula: ; In the formula, The longitudinal wave velocity is the horizontal bedding velocity in the square rock sample. This represents the distance between opposite faces of horizontal bedding planes in a square rock sample. The propagation time of the sound wave through the horizontal bedding in the square rock sample is given.

[0042] The longitudinal wave velocity of the horizontal bedding in the Y direction is also calculated using the above formula, with only the corresponding parameters replaced.

[0043] The longitudinal wave velocity perpendicular to the bedding in a square rock sample is shown in the following formula: ; In the formula, The longitudinal wave velocity is the horizontal bedding velocity in the square rock sample. This represents the distance between opposite faces of horizontal bedding planes in a square rock sample. The propagation time of the sound wave through the horizontal bedding in the square rock sample is given.

[0044] Step 5: Obtain the development index of core bedding based on longitudinal wave velocity.

[0045] Example 5 Based on Examples 3 and 4, in step 5 of this example, the development index of core bedding is obtained based on the longitudinal wave velocity. When a full-diameter shale core is processed into a plunger sample, the core bedding development index is as follows: ; In the formula, The index of shale bedding development; V H The longitudinal wave velocity is the velocity parallel to the bedding direction in the plunger rock sample. V V The longitudinal wave velocity in the direction perpendicular to the bedding plane in the plunger rock sample; When a full-diameter shale core is processed into a square sample, the core bedding development index is shown in the following formula: ; ; In the formula, The index of shale bedding development; V K The average longitudinal wave velocity parallel to the bedding direction in the square rock sample; V Z The longitudinal wave velocity perpendicular to the bedding direction in the square rock sample; VX and V Y The values ​​represent the longitudinal wave velocities in different parallel bedding directions within a square rock sample.

[0046] Example 6 The quantitative characterization method for the degree of shale bedding development in this embodiment includes the following steps: Step 1: Core sampling and determination of core bedding planes. Based on the research objective, three full-diameter shale cores (10cm in diameter and 10cm-20cm in length) from the study section were selected and numbered 1, 2, and 3.

[0047] The full-diameter cores were obtained from a vertical well. Core #1 has a smooth cross-section at one end, with the vertical angle between the cross-section and the axis of the full-diameter core being 15 degrees. Adjacent full-diameter cores also exhibit this characteristic. Based on this, the core's bedding direction is determined to be at a 15-degree angle to the axis. Core #2 has an uneven cross-section without obvious cracks, but several parallel color-changing boundaries are visible. These color changes represent variations in the sedimentary environment; therefore, the color-changing boundaries are determined to be the bedding planes of this core. Core #3 has an overall uneven fracture surface, but several small, parallel, smooth joint surfaces are visible, and their orientation is similar to that of the other two full-diameter cores. Therefore, the bedding planes of this core are determined to be parallel to the joint surfaces.

[0048] Step 2, Core Processing and Marking. Two plunger samples and one square sample are processed from a full-diameter shale core with the bedding planes determined. The two plunger samples are processed along the direction perpendicular to the bedding planes and parallel to the bedding planes, respectively, and marked with H (horizontal bedding) and V (vertical bedding) for differentiation. The plunger samples are 1 inch in diameter and 4 cm in length, with smooth end faces.

[0049] The square rock sample was processed into a cube with a length of 3 cm. Arrows were drawn along the three sides at one vertex, labeled X, Y (parallel to the bedding direction) and Z (perpendicular to the bedding direction).

[0050] Step 3: Dry the processed plunger rock samples and square rock samples. Dry at 90℃ for 24 hours.

[0051] Step 4: Measure the P-wave velocity of the plunger or square rock sample. First, measure the core dimensions and weight, then measure the ultrasonic P-wave propagation time according to standard SY / T "Laboratory Measurement Specification for Core Acoustic Wave Velocity" and calculate the P-wave velocity. For plunger samples parallel to the bedding plane and those perpendicular to the bedding plane, measure the P-wave velocity along the axial direction in the direction parallel to the bedding plane. V H ) and longitudinal wave velocity perpendicular to the bedding direction ( V V ).

[0052] For square rock samples, the longitudinal wave velocity parallel to the bedding direction was measured along the marked X, Y, and Z directions.V X , V Y ) and longitudinal wave velocity perpendicular to the bedding direction ( V Z The measurement results are shown in Table 1.

[0053] S5, based on the longitudinal wave velocity, obtains the core bedding development index of plunger or square rock samples.

[0054] The following formula is used to calculate the value of the plunger rock sample: ; In the formula, The index of shale bedding development; V H The longitudinal wave velocity is the velocity parallel to the bedding direction in the plunger rock sample. V V The longitudinal wave velocity in the direction perpendicular to the bedding plane in the plunger rock sample; For square rock samples, the following formula is used for calculation: ; ; In the formula, The index of shale bedding development; V K The average longitudinal wave velocity parallel to the bedding direction in the square rock sample; V Z The longitudinal wave velocity perpendicular to the bedding direction in the square rock sample; V X and V Y The values ​​represent the longitudinal wave velocities in different parallel bedding directions within a square rock sample.

[0055] The calculation results are shown in Table 1.

[0056] Table 1. Calculation results of bedding development index for six plunger rock samples and three square rock samples.

[0057] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0059] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for quantitatively characterizing the degree of shale bedding development, characterized in that, Specifically, the following steps are included: Step 1: Obtain a full-diameter shale core and determine the bedding planes of the full-diameter shale core; Step 2: Process the full-diameter shale core to obtain plunger or square rock samples, and mark the bedding direction on the plunger or square rock samples; Step 3: Dry the plunger rock sample or square rock sample; Step 4: First, measure the size and weight of the plunger rock sample or square rock sample, and then measure the longitudinal wave propagation time of the sound wave in the plunger rock sample or square rock sample using an acoustic wave measuring device to obtain the longitudinal wave velocity. Step 5: Obtain the development index of core bedding based on longitudinal wave velocity.

2. The method for quantitatively characterizing the degree of shale bedding development according to claim 1, characterized in that, In step 1, determining the bedding plane of a full-diameter shale core specifically means that if the full-diameter shale core contains straight bedding fractures or lithological variation surfaces, then the bedding fractures or lithological variation surfaces are taken as bedding planes. Otherwise, for relatively horizontal formations, the bedding plane of the core sample taken from a vertical well is perpendicular to the axis of the entire diameter core, the bedding plane of the core sample taken from a horizontal well is parallel to the axis of the entire diameter core, and the angle of the core sample taken from an inclined well is corrected based on the inclination data. For relatively inclined strata, the core axis is corrected based on the dip angle of the strata.

3. The method for quantitatively characterizing the degree of shale bedding development according to claim 1, characterized in that, In step 2, when processing the full-diameter shale core into a plunger sample, there is at least one pair of plunger samples. The bedding direction of one plunger sample is marked as vertical bedding, and the bedding direction of the other plunger sample is marked as horizontal bedding.

4. The method for quantitatively characterizing the degree of shale bedding development according to claim 3, characterized in that, The diameter of the plunger rock sample is 2.5cm to 3.8cm, and the height is 3cm to 5cm.

5. The method for quantitatively characterizing the degree of shale bedding development according to claim 1, characterized in that, In step 2, when the full-diameter shale core is processed into a square rock sample, the bedding direction of the square rock sample is marked with both vertical bedding and horizontal bedding, and the vertical bedding and horizontal bedding are perpendicular to each other.

6. The method for quantitatively characterizing the degree of shale bedding development according to claim 1, characterized in that, In step 3, drying specifically involves placing the processed plunger rock sample or square rock sample into an oven, drying at a temperature of 90℃~100℃ for 24 hours.

7. The method for quantitatively characterizing the degree of shale bedding development according to claim 1, characterized in that, In step 4, the longitudinal wave propagation time of sound waves in the plunger rock sample or square rock sample is measured using an acoustic wave measurement device, and the longitudinal wave velocity is obtained as shown in the following formula: ； In the formula, v is the longitudinal wave velocity, s is the propagation distance, and t is the propagation time.

8. The method for quantitatively characterizing the degree of shale bedding development according to claim 1, characterized in that, In step 5, the development index of core bedding is obtained based on the longitudinal wave velocity. When a full-diameter shale core is processed into a plunger sample, the core bedding development index is as follows: ； In the formula, The index of shale bedding development; V H The longitudinal wave velocity is the velocity parallel to the bedding direction in the plunger rock sample. V V The longitudinal wave velocity in the direction perpendicular to the bedding plane in the plunger rock sample; When a full-diameter shale core is processed into a square sample, the core bedding development index is shown in the following formula: ； ； In the formula, The index of shale bedding development; V K The average longitudinal wave velocity parallel to the bedding direction in the square rock sample; V Z The longitudinal wave velocity perpendicular to the bedding direction in the square rock sample; V X and V Y The values ​​represent the longitudinal wave velocities in different parallel bedding directions within a square rock sample.

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