Hydrofracture horizon determination method, electronic equipment and storage medium

Abstract

The invention discloses a hydrofracture horizon determination method, electronic equipment and a storage medium. The hydrofracture horizon determination method is specifically implemented according to the following steps: extracting geomechanical parameters in a range of 100m above a coal seam roof in a coring hole or histogram; calculating and identifying a rock stratum key layer; the rock stratum key layer is compared with all rock stratum physical parameters, and the position of a layer needing to be fractured is obtained; and determining the layer height of the layer needing to be fractured. The electronic equipment comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, and the processor implements the hydraulic fracturing horizon determination method when executing the program. And a computer program is stored on the storage medium, and the hydraulic fracturing horizon determination method is realized when the computer program is executed by the processor. The problem that in the prior art, due to the fact that blindness of middle position determination is large, on-site rock stratum internal pressure drilling and pressure relief effects are poor, and safety production is affected is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine rock burst disaster prevention and control, and relates to a hydraulic fracturing layer determination method, electronic equipment and a storage medium. Background Art

[0002] In recent years, with the increasing depth of coal mining and the increasing complexity of mining conditions, disasters such as coal mine rock burst and mine earthquake have gradually received attention. According to the current research on such issues by relevant experts and scholars, a major cause of coal mine rock burst and mine earthquake disasters is the sudden breakage of the thick and hard roof of the overlying rock layer of the coal seam. Therefore, a large number of experts have studied methods to weaken the overlying rock layer. Directional drilling hydraulic fracturing in underground coal mines has gradually been widely used in coal mines due to its wide coverage, high accuracy, and good pressure relief effect. However, in on-site engineering practice, it is often encountered that the blindness of layer determination leads to pressure drilling in the on-site rock layer and poor pressure relief effect, which affects safe production. Summary of the invention

[0003] The purpose of the present invention is to provide a method for determining hydraulic fracturing layers, an electronic device and a storage medium, which solve the technical problem of relatively large blindness in layer determination in the prior art.

[0004] To achieve the above object, the first technical solution adopted by the present invention is a method for determining a hydraulic fracturing layer, which is specifically implemented according to the following steps: Step 1: Extract geomechanical parameters within 100m above the coal seam roof from the core holes or column charts near the fracturing project implementation area; Step 2: Calculate and identify the key layers of the rock formation according to the geomechanical parameters in step 1; Step 3: Compare the calculated key layers of the rock formation with the physical parameters in the core holes or histograms of each rock formation to obtain the layers that need to be fractured; Step 4: Determine the height of the layer to be fractured.

[0005] The first technical solution of the present invention is also characterized in that: The geomechanical parameters in step 1 include layer thickness in the column chart, vertical distance from the roof to the coal seam, bulk density, and elastic modulus.

[0006] Step 2 is as follows: According to the lithology and classification of the overlying rock formations on the working face, the coal rock mechanical parameters are substituted into formula (1) for calculation: (1) In formula (1): represents the load exerted by the mth rock layer on the 1st rock layer; γi represents the bulk density of the ith rock layer, (i=1, 2, ..., m); Ei represents the elastic modulus of the ith rock layer, (i=1, 2, ..., m); (2) When the bending and sinking amount of the lower rock layer of the m+1th rock layer is greater than the bending and sinking amount of the current layer, the rock layers above the m+1th rock layer do not need the lower rock layer to bear the load, then: (3) The specific method for determining the key rock layer is as follows: assume that the rock layers above the coal seam are the 1st, 2nd, 3rd…m…n layers (m<n) in sequence, start the calculation from the 1st rock layer, and stop the calculation when formula (3) is established, that is, this layer is the key layer.

[0007] The physical parameters in step 3 include core sampling rate, saturated uniaxial compressive strength, and vertical distance from the coal seam roof to the coal seam.

[0008] The comparison in step 3 includes: comparing whether the core sampling rate in the key rock layer is greater than 80%, whether the saturated uniaxial compressive strength is greater than 30MPa, and whether the vertical distance from the coal seam roof to the coal seam is greater than the equipment fracturing radius value; when the key rock layer meets the conditions that the core sampling rate is greater than 80%, the saturated uniaxial compressive strength is greater than 30MPa, and the vertical distance from the coal seam roof to the coal seam is greater than the equipment fracturing radius value, it is the layer that needs to be fractured.

[0009] In step 4, the floor height is calculated according to the following formula: H = Hi + 1 / 2hi (4) In formula (4), H represents the layer height, hi represents the thickness of the specified rock layer, and Hi represents the vertical distance from the coal seam roof to the coal seam (i = 1, 2, ..., m, n, (m < n)).

[0010] The second technical solution adopted by the present invention is an electronic device, including a memory, a processor and a computer program stored in the memory and executable on the processor, and the above-mentioned method for determining the hydraulic fracturing layer is implemented when the processor executes the program.

[0011] Another technical solution adopted by the present invention is a non-transitory computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the above-mentioned method for determining the hydraulic fracturing layer is implemented.

[0012] Compared with the prior art, the present invention has the following beneficial effects: The present invention identifies key layers by calculating geomechanical parameters in a columnar diagram within 100m above the coal seam roof in a core hole or a columnar diagram near the implementation area of ​​the fracturing project, and compares the key layers with the physical parameters in the core holes or columnar diagrams of each rock layer to determine the hydraulic fracturing layer and reference layer height of the weakened thick hard roof in the coal mine. The data in the present invention is easy to obtain, and the hydraulic fracturing layer and reference layer height of the weakened thick hard roof in the coal mine can be clearly calculated, which solves the problem that the blindness of layer determination in the prior art leads to poor pressure drilling and pressure relief effects in the on-site rock formation, which affects safe production. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the flow of the method for determining the hydraulic fracturing layer of the present invention. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0015] Example 1 like Figure 1 As shown, the method for determining the hydraulic fracturing layer disclosed in this embodiment is specifically implemented according to the following steps: Step 1: Extract geomechanical parameters within 100m above the coal seam roof from the core holes or column charts near the fracturing project implementation area; Rock coring refers to the process of obtaining underground rock samples through drilling technology. Its main purpose is to study geological structure and mineral conditions by drilling cores, and to obtain information or parameters on the lithology, lithofacies, physical properties, oil generation, oil content and other aspects of the stratum. Rock coring is done by drilling a hole underground using a coring drill bit and a coring drill tool, and retaining a columnar core at the center of the bottom of the hole, and then taking out the core for observation, identification and analysis experiments. This technology can go deep into the earth, understand the underground rock structure, verify geological theoretical speculation, and thus reveal detailed information about the stratum.

[0016] The rock column is a geological map that is mainly used to comprehensively reflect the stratigraphic characteristics, thickness and contact relationship of each geological age in a region. It is a tabular map compiled based on field measured stratigraphic profile data and restored to a horizontal state according to the superposition relationship between new and old strata. The main contents of the rock column include: Stratigraphic characteristics: Displays the strata and lithological characteristics of different geological ages.

[0017] Thickness: Displays the thickness of each rock layer.

[0018] Contact relationship: Displays the contact relationship between different strata, such as conformable contact, unconformable contact, etc.

[0019] Rock column diagrams are widely used in geology, mainly for: Stratigraphic comparison: helps geologists compare the stratigraphic characteristics of different regions and understand the lateral changes of the stratigraphic characteristics.

[0020] Geological structural research: studying geological structural phenomena by analyzing the contact relationship of strata.

[0021] Mineral resource exploration: In mineral resource exploration, rock column diagrams help determine the location and size of ore bodies.

[0022] In addition, the scale of rock column charts is usually larger than that of geological maps in order to show stratigraphic information in more detail.

[0023] Step 2: Calculate and identify the key layers of the rock formation according to the geomechanical parameters in step 1; Step 3: Compare the calculated key layers of the rock formation with the physical parameters in the core holes or histograms of each rock formation to obtain the layers that need to be fractured; Step 4: Determine the height of the layer to be fractured.

[0024] Example 2 On the basis of Example 1, the geomechanical parameters in step 1 include the layer thickness in the column chart, the vertical distance from the roof to the coal seam, the bulk density, and the elastic modulus. Specifically, several core holes or column charts are extracted near the implementation area of ​​the fracturing project, and the column chart-related geological parameters and mechanical parameters within 100m above the coal seam roof are shown in Table 1.

[0025] Table 1

[0026] In Table 1, hi is the thickness of the rock layer with the specified serial number, and Hi is the vertical distance from the coal seam roof to the coal seam (i=1, 2,…, m, n, (m<n)).

[0027] Example 3 Based on Example 1, step 2 is specifically as follows: according to the lithology and classification of the overlying rock formation on the working face, the coal rock mechanical parameters are substituted into formula (1) for calculation: (1) In formula (1): represents the load exerted by the mth rock layer on the 1st rock layer; γi represents the bulk density of the ith rock layer, (i=1, 2, ..., m); Ei represents the elastic modulus of the ith rock layer, (i=1, 2, ..., m); (2) When the bending and sinking amount of the lower rock layer of the m+1th rock layer is greater than the bending and sinking amount of the current layer, the rock layers above the m+1th rock layer do not need the lower rock layer to bear the load, then: (3) The specific method for determining the key rock layer is as follows: assume that the rock layers above the coal seam are the 1st, 2nd, 3rd…m…n layers (m<n) in sequence, start the calculation from the 1st rock layer, and stop the calculation when formula (3) is established, that is, this layer is the key layer.

[0028] Example 4 Based on Example 1, the physical parameters in step 3 include core recovery rate, saturated uniaxial compressive strength, and vertical distance from the coal seam roof to the coal seam.

[0029] The comparison in step 3 includes: comparing whether the core collection rate in the key layer of the rock formation is greater than 80%, whether the saturated uniaxial compressive strength is greater than 30MPa, and whether the vertical distance from the coal seam roof to the coal seam is greater than the equipment fracturing radius value; the greater the core collection rate and the greater the saturated uniaxial compressive strength, the greater the necessity of fracturing the rock formation. In addition, since the current fracturing equipment has a fracturing radius range, the vertical distance from the coal seam roof to the coal seam must be greater than the equipment fracturing radius value R. Therefore, when the key layer of the rock formation meets the conditions that the core collection rate is greater than 80%, the saturated uniaxial compressive strength is greater than 30MPa, and the vertical distance from the coal seam roof to the coal seam is greater than the equipment fracturing radius value, it is a layer that needs to be fractured.

[0030] Example 5 Based on Example 1, the layer height in step 4 is calculated according to the following formula: H = Hi + 1 / 2hi (4) In formula (4), H represents the layer height, hi represents the thickness of the specified rock layer, and Hi represents the vertical distance from the coal seam roof to the coal seam (i = 1, 2, ..., m, n, (m < n)).

[0031] Example 6 This embodiment discloses an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for determining the hydraulic fracturing layer described in Embodiments 1-5 is implemented.

[0032] Example 7 This embodiment discloses a storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for determining the hydraulic fracturing layer described in embodiments 1-5 is implemented.

[0033] Example 8 In combination with Examples 1-5, the method for determining the hydraulic fracturing layer disclosed in this embodiment specifically includes the following steps: Step 1: extract geomechanical parameters such as layer thickness, vertical distance from the roof to the coal seam, bulk density, elastic modulus, etc. from the core holes or column charts about 100m above the coal seam roof in the vicinity of the fracturing project implementation area, compile serial numbers, and form a borehole geomechanical parameter table as shown in Table 2.

[0034] Table 2

[0035] Step 2, substitute the parameters in Table 2 into equations (1) and (2) for calculation. When the load formed by the mth rock layer on the 1st rock layer is greater than the load formed by the m+1th rock layer on the 1st rock layer, it means that the rock layers above the m+1th rock layer do not need the lower rock layers to bear the load, that is, the m+1th rock layer is the first key layer. By analogy, the key layers within 100m above the coal seam roof can be calculated. In particular, if the nth layer and the n+1th layer are both key layers, then the nth layer and the n+1th layer are combined key layers. The calculation results are shown in the notes of Table 2.

[0036] Step 3, the calculated key layer is compared with the core sampling rate and saturated uniaxial compressive strength in the core holes or column charts of each rock layer.

[0037] The core sampling rate and saturated uniaxial compressive strength of the key rock layers in each borehole were extracted and numbered, as shown in Table 3.

[0038] Table 3

[0039] Step 4, determine whether the core sampling rate is greater than 80%, whether the saturated uniaxial compressive strength is greater than 30MPa, and whether the vertical distance from the coal seam roof to the coal seam is greater than the equipment fracturing radius value. Here, the value is 30m. Based on this, it can be determined that the i-th rock layer is the fracturing layer. The judgment results are shown in Table 3. The layer height H is: H=Hi+1 / 2hi=33.31+21.69=55m. It should be noted that this calculated layer result is a reference for the construction fracturing layer rather than a restriction.

[0040] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0041] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0042] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be 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 the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining hydraulic fracturing layers, characterized in that: Follow the steps below to implement it: Step 1: Extract geomechanical parameters within 100m above the coal seam roof from the core holes or column charts near the fracturing project implementation area; Step 2: Calculate and identify the key layers of the rock formation according to the geomechanical parameters in step 1; Step 3: Compare the calculated key layers of the rock formation with the physical parameters in the core holes or histograms of each rock formation to obtain the layers that need to be fractured; Step 4: determine the layer height of the layer to be fractured.

2. The method for determining hydraulic fracturing layers according to claim 1, characterized in that: The geomechanical parameters in step 1 include layer thickness in the column chart, vertical distance from the roof to the coal seam, bulk density, and elastic modulus.

3. The method for determining hydraulic fracturing layer according to claim 1, characterized in that: The step 2 is specifically as follows: According to the lithology and classification of the overlying rock formations on the working face, the coal rock mechanical parameters are substituted into formula (1) for calculation: （1） In formula (1): represents the load exerted by the mth rock layer on the 1st rock layer; γi represents the bulk density of the ith rock layer, (i=1, 2, ..., m); Ei represents the elastic modulus of the ith rock layer, (i=1, 2, ..., m); （2） When the bending and sinking amount of the lower rock layer of the m+1th rock layer is greater than the bending and sinking amount of the current layer, the rock layers above the m+1th rock layer do not need the lower rock layer to bear the load, then: （3） The specific method for determining the key rock layer is as follows: assume that the rock layers above the coal seam are the 1st, 2nd, 3rd…m…n layers (m<n) in sequence, start the calculation from the 1st rock layer, and stop the calculation when formula (3) is established, that is, this layer is the key layer.

4. The method for determining hydraulic fracturing layers according to claim 1, characterized in that: The physical parameters in step 3 include core sampling rate, saturated uniaxial compressive strength, and vertical distance from the coal seam roof to the coal seam.

5. The method for determining hydraulic fracturing layers according to claim 4, characterized in that: The comparison in step 3 includes: comparing whether the core sampling rate in the key layer of the rock formation is greater than 80%, whether the saturated uniaxial compressive strength is greater than 30MPa, and whether the vertical distance from the coal seam roof to the coal seam is greater than the equipment fracturing radius value; when the key layer of the rock formation meets the conditions that the core sampling rate is greater than 80%, the saturated uniaxial compressive strength is greater than 30MPa, and the vertical distance from the coal seam roof to the coal seam is greater than the equipment fracturing radius value, it is a layer that needs to be fractured.

6. The method for determining hydraulic fracturing layers according to claim 1, characterized in that: In step 4, the floor height is calculated according to the following formula: H=Hi+1 / 2hi(4) In formula (4), H represents the layer height, hi represents the thickness of the specified rock layer, and Hi represents the vertical distance from the coal seam roof to the coal seam (i = 1, 2, ..., m, n, (m < n)).

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method for determining the hydraulic fracture layer according to any one of claims 1 to 6 is implemented.

8. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for determining the hydraulic fracture layer according to any one of claims 1 to 6 is implemented.

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