Shale fracture pressure continuous depth evaluation method and device, electronic equipment and storage medium

Abstract

The invention discloses a shale fracture pressure continuous depth evaluation method and device, electronic equipment and a storage medium. The method comprises the following steps: determining a first physical characteristic parameter of target shale; and according to the first physical characteristic parameter of the target shale, the fracture pressure of the target shale is determined through a fracture pressure model. According to the scheme, the bursting pressure model is established in advance according to the reference shale core physical characteristic parameters and the reference shale core bursting pressure, after the first physical characteristic parameters are obtained, the bursting pressure of the target shale can be directly obtained according to the bursting pressure model, and it can be avoided that in an existing determining method, the bursting pressure of the target shale cannot be obtained. Errors generated when multiple pieces of parameter data are evaluated through the logging data, so that the accuracy of shale fracture pressure prediction is improved, and meanwhile, the acquisition of the fracture pressure can provide an accurate data basis for other geological exploration and development activities.

Description

Technical Field

[0001] This invention relates to the field of petroleum exploration and development technology, and in particular to a method, apparatus, electronic device and storage medium for continuous depth evaluation of shale fracture pressure. Background Technology

[0002] Shale fracture pressure is fundamental to oil and gas well drilling engineering design and serves as the basis for rationally selecting drilling fluids and determining casing depth. Accurately predicting shale fracture pressure allows for greater foresight in the drilling process, playing a crucial role in pressure balancing drilling, reservoir protection, blowout prevention, increasing drilling speed, and reducing drilling costs.

[0003] Methods for obtaining shale fracture pressure include extended leakage test (XLOT) or small-scale fracturing processes, but these are only applicable to the current well and depth, and are expensive, making them unsuitable for large-scale applications. Therefore, model prediction methods are commonly used. These methods currently consider the stress state around the wellbore, using the Kirsch equations to derive the shale fracture pressure formula based on the stress around a small circular hole in an infinite slab. This formula requires knowledge of mechanical parameters such as pore pressure, tensile strength, static Poisson's ratio, and maximum and minimum horizontal principal stresses. Well logging data inevitably introduces errors in evaluating these parameters, leading to inaccurate shale fracture pressure readings. Summary of the Invention

[0004] This invention provides a method, apparatus, electronic device, and storage medium for continuous depth evaluation of shale fracture pressure, in order to solve the problem that errors exist in the mechanical parameters of the formula for evaluating fracture pressure based on well logging data, resulting in inaccurate shale fracture pressure.

[0005] According to one aspect of the present invention, a method for evaluating the continuous depth of shale fracture pressure is provided, comprising:

[0006] The first physical characteristic parameters of the target shale are determined; the first physical characteristic parameters include: clay content, total organic carbon content and total porosity of the target shale, and the first physical characteristic parameters characterize the physical characteristics of the target shale.

[0007] The fracture pressure of the target shale is determined by a fracture pressure model based on the first physical property parameters of the target shale. The fracture pressure model is established based on the fracture pressure of a reference shale core and the second physical property parameters of the reference shale core, and is used to characterize the functional relationship between the fracture pressure of the reference shale core and the sum of the physical property parameters. The reference shale core and the target shale are located in the same geological area or in the same well.

[0008] According to another aspect of the present invention, a shale fracture pressure continuous depth evaluation device is provided, comprising:

[0009] The parameter determination module is used to determine the first physical characteristic parameters of the target shale; the first physical characteristic parameters include: the clay content of the target shale, the total organic carbon content of the target shale, and the total porosity of the target shale, and the first physical characteristic parameters characterize the physical characteristics of the target shale;

[0010] The target shale fracture pressure determination module is used to determine the fracture pressure of the target shale based on the first physical property parameters of the target shale using a fracture pressure model. The fracture pressure model is established based on the fracture pressure of a reference shale core and the second physical property parameters of the reference shale core, and is used to characterize the functional relationship between the fracture pressure of the reference shale core and the sum of the physical property parameters. The reference shale core and the target shale are located in the same geological area or in the same well.

[0011] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0012] At least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the shale fracture pressure continuous depth evaluation method according to any embodiment of the present invention.

[0013] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing computer instructions for causing a processor to execute and implement the shale fracture pressure continuous depth evaluation method according to any embodiment of the present invention.

[0014] The technical solution of this invention determines the fracture pressure of the target shale by using a fracture pressure model based on the first physical characteristic parameters of the target shale. This fracture pressure model is established in advance based on the physical characteristic parameters and fracture pressure of a reference core. After obtaining the first physical characteristic parameters, the fracture pressure of the target shale can be directly obtained from the fracture pressure model. This avoids the errors that occur when evaluating multiple parameter data through well logging data in existing determination methods, thereby improving the accuracy of shale fracture pressure prediction. At the same time, obtaining the fracture pressure can also provide an accurate data basis for other geological exploration and development activities.

[0015] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A flowchart illustrating a method for evaluating the continuous depth of shale fracture pressure, provided in an embodiment of the present invention;

[0018] Figure 2 This is a result image of continuous depth processing of target shale fracture pressure provided in an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of porosity fluid distribution provided in an embodiment of the present invention;

[0020] Figure 4 A reference shale core stress-strain curve is provided for an embodiment of the present invention.

[0021] Figure 5 A cross-plot of the fracture pressure of a reference shale core versus the sum of clay content, total organic carbon content, and total porosity, provided for an embodiment of the present invention;

[0022] Figure 6 This is a schematic diagram of a shale fracture pressure continuous depth evaluation device provided in an embodiment of the present invention;

[0023] Figure 7 A schematic diagram of the electronic device used to implement the shale fracture pressure continuous depth evaluation method according to an embodiment of the present invention. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] Figure 1 This is a flowchart illustrating a method for evaluating the continuous depth of shale fracture pressure according to an embodiment of the present invention. This embodiment is applicable to situations involving the acquisition of shale fracture pressure. The method can be executed by a device for evaluating the continuous depth of shale fracture pressure, which can be implemented in hardware and / or software and can be configured in any electronic device with network communication capabilities. Figure 1 As shown, the method includes:

[0027] S110. Determine the first physical property parameters of the target shale.

[0028] The first physical characteristic parameter includes: the clay content of the target shale, the total organic carbon content of the target shale, and the total porosity of the target shale. The first physical characteristic parameter characterizes the physical characteristics of the target shale.

[0029] Total organic carbon content is expressed as the amount of organic matter in water, based on the carbon content.

[0030] The first physical property parameters of the target shale are determined based on the well logging data of the target shale.

[0031] Optionally, determine the first physical property parameters of the target shale, including steps A1-A2:

[0032] Step A1: Obtain well logging data for the target shale.

[0033] The well logging data for the target shale includes at least: the natural gamma logging curve value of the target shale, the resistivity of the target shale, the compensated neutron of the target shale, and the density of the target shale.

[0034] The target shale is tested using detection equipment to obtain well logging data of the target shale.

[0035] Step A2: Determine the first physical property parameters of the target shale based on the well logging data of the target shale.

[0036] Based on the correspondence between the logging data of the target shale and the first physical characteristic parameter, the logging data of the target shale is processed to obtain the first physical characteristic parameter of the target shale.

[0037] Furthermore, the above correspondence is the functional relationship between each data point of the pre-established well logging data and each data point of the physical characteristic parameters.

[0038] Optionally, the first physical property parameters of the target shale are determined based on the well logging data of the target shale, including steps B1-B3:

[0039] Step B1: Determine the clay content of the target shale based on the extreme values ​​of the natural gamma logging curve of the target shale and the natural gamma logging curve of the pure sandstone section of the target formation.

[0040] The target stratum is the stratum in which the target shale is located.

[0041] The maximum and minimum values ​​of the natural gamma logging curves of the target shale and the natural gamma logging curves of the pure sandstone section of the target formation are input into the clay content model for calculation to obtain the clay content of the target shale.

[0042] The clay content model is a pre-established functional relationship between the natural gamma logging curve value and the clay content.

[0043] Optionally, the clay content of the target shale is determined based on the extreme values ​​of the natural gamma-ray logging curves of the target shale and the natural gamma-ray logging curves of the pure sandstone section of the target formation, including steps C1-C2:

[0044] Step C1: Determine the relative value of the natural gamma ray of the target shale based on the natural gamma logging curve value of the target shale and the extreme value of the natural gamma logging curve of the pure sandstone section of the target formation.

[0045] The natural gamma logging curve values ​​of the target shale and the extreme values ​​of the natural gamma logging curves of the pure sandstone section of the target formation are input into the natural gamma relative value model to calculate the natural gamma relative value of the target shale.

[0046] The natural gamma relative value model can be expressed by the following formula:

[0047]

[0048] Where ΔGR is the relative value of the natural gamma ray of the target shale; GR is the natural gamma logging curve value of the target shale; GR min The minimum value of the natural gamma-ray logging curve for the pure sandstone section of the target formation; GR max The maximum value of the natural gamma logging curve for the pure sandstone section of the target formation.

[0049] Step C2: Determine the clay content of the target shale based on its natural gamma relative value and the empirical coefficient of stratigraphic age.

[0050] The natural gamma relative value of the target shale and the empirical coefficient of stratigraphic age are input into the clay content model to calculate the clay content of the target shale.

[0051] Among them, the stratigraphic age empirical coefficient is the stratigraphic age empirical coefficient of the stratum where the target stratum is located.

[0052] The clay content model can be expressed by the following formula:

[0053]

[0054] In the formula, V SH测井 denoted as % (clay content of the target shale); c is an empirical coefficient related to stratigraphic age.

[0055] Step B2: Determine the total organic carbon content of the target shale based on its resistivity and the resistivity of the non-hydrocarbon source mudstone layer in the target stratigraphic position.

[0056] For example, determining the total organic carbon content based on the resistivity of the target shale in the well logging data involves calculating the total organic carbon content at continuous depths using well logging data such as the resistivity-porosity curve or density curve of the target shale. Taking the overlay method of the resistivity-porosity curve of the target shale (ΔlgR method) as an example, the method for determining the total organic carbon content of the target shale is as follows:

[0057]

[0058] TOC = (Δlg R)·10 (2.297-0.1688LOM)

[0059] Where TOC is the total organic carbon content of the target shale; K is the proportional coefficient of the relative miscibility scale; R t R represents the resistivity of the target shale; Δt represents the sonic transit time logging value of the target shale; 基线 Resistivity logging values ​​for non-hydrocarbon source rock mudstone formations; Δt 基线 ΔlgR represents the sonic transit time logging value for non-hydrocarbon source rocks; LOM is an index reflecting the maturity of organic matter, which can be calibrated by cross-plotting geochemical analysis data and logging response characteristics of the study area; ΔlgR is an intermediate variable.

[0060] Step B3: Determine the total porosity of the target shale based on the neutron density cross-plot of the target shale.

[0061] Among them, the neutron density cross plot of the target shale establishes the relationship between the compensated neutrons of the target shale and the density of the target shale, thereby characterizing the total porosity of the target shale.

[0062] A neutron density cross plot of the target shale is constructed based on the compensated neutrons and density of the target shale, and the total porosity of the target shale is determined based on the neutron density cross plot.

[0063] Furthermore, the principle of determining the total porosity of the target shale using the neutron density cross plot is to use a cyclic iterative approximation method to accurately determine the fluid parameters of the target shale's compensated neutron and density, the target shale skeleton parameters, and the dry clay skeleton parameters at each depth point. Then, using the fluid parameters of the target shale's compensated neutron and density, the target shale skeleton parameters, and the dry clay skeleton parameters, a cross plot triangle is established, i.e., the neutron density cross plot of the target shale. The total porosity of the target shale is calculated based on the neutron density cross plot.

[0064] S120. Based on the first physical property parameters of the target shale, determine the fracture pressure of the target shale using a fracture pressure model.

[0065] The first physical property parameters of the target shale are input into the fracture pressure model, and the fracture pressure of the target shale is calculated.

[0066] For example, Figure 2 The result of continuous depth processing of the fracture pressure of the target shale is shown in the image. Figure 2As shown, the first channel is the lithology indicator channel for the target shale. The solid line represents the natural gamma ray logging curve value of the target shale, and the dashed line represents the wellbore curve. The natural gamma ray logging curve of the target shale mainly characterizes the lithological changes of the target shale, while the wellbore curve mainly indicates the quality of the wellbore. The second channel is the depth channel, indicating the distance of the target formation from the wellhead. The third channel is the three porosity curve channel. The solid line represents the acoustic transit time (AC) curve of the target shale, the dashed line represents the bulk density (DEN) curve of the target shale, and the dotted line represents the compensated neutron (CNL) curve of the target shale. All three curves can be used to calculate the porosity, characterizing the formation properties. The fourth track represents the resistivity curve of the target shale. The solid line represents the deep array induced resistivity curve (AT90), the short dashed line represents the medium array induced resistivity curve (AT60), and the dotted line represents the shallow array induced resistivity curve (AT10). The resistivity curve of the target shale mainly characterizes its electrical conductivity, thereby evaluating the lithology and fluid properties of the target stratigraphic unit. The fifth track represents the total organic carbon content of the target shale. The solid line represents the total organic carbon content (TOC) of the target shale calculated by the ΔlgR method from the AT90 and AC curves. The sixth track represents the total porosity of the target shale. The solid line represents the total porosity (POR) calculated by nuclear magnetic resonance. The seventh track represents the clay content of the target shale. The solid line represents the total porosity (VSH) of the target shale calculated by natural gamma logging curves. The eighth track represents the fracture pressure of the target shale. The solid line represents the calculated fracture pressure of the target shale.

[0067] The fracture pressure model is established based on the fracture pressure of the reference shale core and the second physical property parameters of the reference shale core. It is used to characterize the functional relationship between the fracture pressure of the reference shale core and the sum of the physical property parameters. The reference shale core and the target shale are located in the same geological area or in the same well.

[0068] Optional, the process for determining the rupture pressure model includes steps D1-D3:

[0069] Step D1: Determine the second physical property parameters of the reference shale core.

[0070] The second physical characteristic parameters include: clay content, total organic carbon content, and total porosity of the reference shale core. These parameters characterize the physical properties of the reference shale core.

[0071] The total organic carbon content of the reference shale core was measured by burning the core. The measurement principle is to remove the inorganic carbon in the reference shale core with dilute hydrochloric acid, then burn it in a high-temperature oxygen stream to convert the total organic carbon into carbon dioxide. The carbon dioxide content is then detected by an infrared detector. Finally, the total organic carbon content of the reference shale core is calculated based on the correspondence between carbon dioxide and total organic carbon content.

[0072] Clay content (V) of reference shale core SH () refers to the volume percentage of clay minerals in a reference shale core. Clay, also known as clay minerals, is a very small-particle plastic silicate mineral formed after weathering on the Earth's surface.

[0073] X-ray diffraction was performed on a reference shale core to obtain a diffraction pattern. Analysis of the diffraction pattern determined the clay content of the reference shale core.

[0074] X-ray diffraction is a mineral composition detection technique. It is an experimental method that uses X-ray diffraction to analyze the diffraction pattern of a reference shale core to obtain the mineral types and their contents.

[0075] Total porosity of reference shale core determined by nuclear magnetic resonance and gas method.

[0076] Furthermore, the method described above is used to determine the total porosity of the reference shale core because the pores in the core after the loss of oil and gas are small and contain fluid; therefore, accurate porosity test results can be obtained using nuclear magnetic resonance (NMR). The pores in the reference shale core after the loss of oil and gas are small and gas-permeable; therefore, accurate porosity measurement results can be obtained using a gas method.

[0077] Among them, the nuclear magnetic resonance method measures the porosity of the reference shale core using a nuclear magnetic resonance instrument; the gas method measures the porosity of the reference shale core using helium gas.

[0078] Optionally, determine the second physical property parameters of the reference shale core, including steps E1-E3:

[0079] Step E1: Measure the reference shale core using a nuclear magnetic resonance instrument to obtain the nuclear magnetic porosity.

[0080] The principle behind nuclear magnetic resonance (NMR) porosity measurement is based on the interaction between nuclear spins and the liquid in the pores of a reference shale core, which causes a change in the relaxation time of the NMR signal, indirectly yielding the porosity of the reference shale core. Relaxation time represents the time it takes for an NMR instrument in equilibrium to return to its original equilibrium state after being subjected to a momentary external disturbance.

[0081] The porosity of the drilled reference shale core was measured using a nuclear magnetic resonance (NMR) instrument to obtain the NMR porosity (φ). NMR The porosity measured at this time is the pore space after the oil and gas have dissipated.

[0082] For example, such as Figure 3 As shown, φ NMRThe pore space is occupied by clay-bound water, immovable fluid, and the remaining portion of movable fluid within the skeleton.

[0083] Furthermore, such as Figure 3 As shown, from top to bottom, the white part is the skeleton, and the other parts are pores. Different colors represent the types of fluids in the pores. The gray part is the movable fluid, which is any combination of oil, gas and water. The movable fluid is further divided into the lost part and the remaining part. The dark gray part is the immovable fluid, which is any combination of oil, gas and water. The black part is clay-bound water, mainly intercrystalline water and clay interlayer water.

[0084] The nuclear magnetic resonance porosity measured using the above method can be used to non-destructively measure reference shale cores and can be performed under relatively realistic conditions, providing more accurate porosity measurement results for reference shale cores.

[0085] Step E2: Introduce helium into the reference shale core and determine the gas porosity based on the degree of helium escape.

[0086] The principle of gas-based porosity measurement is based on the compressibility of gas. By measuring the change in resistance of gas in the pores of a reference shale core under different pressures, the porosity is calculated. This porosity measurement method is suitable for reference shale cores with high density, low porosity, and stable gas permeability.

[0087] Helium gas was introduced into a reference shale core, and the gas porosity (φ) was measured based on the degree of helium escape. He At this point, the porosity measured is the pore space where oil and gas have escaped.

[0088] For example, such as Figure 3 As shown, φ He Porosity refers to the porosity of the portion of the fluid lost from the movable fluid within the skeleton.

[0089] Step E3: Sum the gas porosity and nuclear magnetic resonance porosity to obtain the total porosity of the reference shale core.

[0090] Gas porosity (φ) He ) and nuclear magnetic porosity (φ NMR The total porosity of the reference shale core is obtained by adding the two components together. This can be expressed as follows:

[0091] φ=φ NMR +φ He

[0092] Step D2: Determine the fracture pressure of the reference shale core through a fracture test.

[0093] The fracturing experiment involved continuously pressurizing a reference shale core until it fractured.

[0094] Furthermore, the fracture experiment is an experimental study that observes the failure conditions, failure process, and changes in the physical properties of the reference shale core during the failure process.

[0095] During the fracturing experiment, a certain confining pressure was applied to the reference shale core and the axial pressure was gradually increased until the reference shale core fractured. The axial pressure corresponding to the fracture of the reference shale core was taken as the fracture pressure of the reference shale core.

[0096] Furthermore, such as Figure 4 As shown, the horizontal axis represents strain, in % (%), with a scale from 0 to 0.6; the vertical axis represents stress, in megapascals (MPa), with a scale from 0 to 240. As stress increases, the strain of the reference shale core increases until the core fractures. After fracture, the strain continues to increase, while the required stress gradually decreases. The maximum stress during this process is the fracture pressure. Here, stress refers to axial pressure.

[0097] Step D3: Establish a fracture pressure model based on the sum of the fracture pressure of the reference shale core and the second physical property parameters of the reference shale core.

[0098] First, the second physical property parameters of the reference shale core are summed. After the summation is completed, a fracture pressure model is established based on the fracture pressure of the reference shale core and the sum of the second physical property parameters of the reference shale core.

[0099] Optionally, the rupture pressure model can be expressed as follows:

[0100] P f =α(V SH +TOC+φ) β

[0101] Among them, P f To reference the fracture pressure of shale cores, V SH The reference shale core contains clay, TOC contains total organic carbon, φ contains total porosity, and α and β are constant values.

[0102] For example, Figure 5 is a cross-plot of the fracture pressure of a reference shale core against the sum of its clay content, total organic carbon content, and total porosity. Figure 5As shown in the figure, the horizontal axis represents the sum of clay content, TOC, and porosity, in percentages (%), with a scale from 0 to 80; the vertical axis represents the fracturing pressure, in megapascals (MPa). The fracturing pressure decreases non-linearly as the sum of the three increases. Specifically, clay content refers to the clay content of the reference shale core; TOC refers to the total organic carbon content of the reference shale core; porosity refers to the total porosity of the reference shale core; and fracturing pressure refers to the fracturing pressure of the reference shale core.

[0103] The technical solution of this embodiment determines the fracture pressure of the target shale by using a fracture pressure model based on the first physical characteristic parameters of the target shale. This fracture pressure model is established in advance based on the physical characteristic parameters and fracture pressure of a reference shale. After obtaining the first physical characteristic parameters, the fracture pressure of the target shale can be directly obtained from the fracture pressure model. This avoids the errors that occur when evaluating multiple parameter data through well logging data in existing determination methods, thereby improving the accuracy of shale fracture pressure prediction. At the same time, obtaining the fracture pressure can also provide an accurate data basis for other geological exploration and development activities.

[0104] Figure 6 This is a schematic diagram of a shale fracture pressure continuous depth evaluation device provided in an embodiment of the present invention. This embodiment is applicable to the acquisition of shale fracture pressure. The shale fracture pressure continuous depth evaluation device can be implemented in hardware and / or software, and can be configured in any electronic device with network communication capabilities. Figure 6 As shown, the device includes: a parameter determination module 210 and a target shale fracture pressure determination module 220, wherein:

[0105] Parameter determination module 210: used to determine the first physical characteristic parameters of the target shale; the first physical characteristic parameters include: clay content of the target shale, total organic carbon content of the target shale and total porosity of the target shale, and the first physical characteristic parameters characterize the physical characteristics of the target shale;

[0106] The target shale fracture pressure determination module 220 is used to determine the fracture pressure of the target shale based on the first physical property parameters of the target shale through a fracture pressure model. The fracture pressure model is established based on the fracture pressure of the reference shale core and the second physical property parameters of the reference shale core, and is used to characterize the functional relationship between the fracture pressure of the reference shale core and the sum of the physical property parameters. The reference shale core and the target shale are located in the same geological area or in the same well.

[0107] Optionally, the parameter determination module 210 includes:

[0108] Well logging data acquisition unit: used to acquire well logging data of the target shale; the well logging data of the target shale includes at least: the natural gamma logging curve value of the target shale, the resistivity of the target shale, the compensated neutron of the target shale, and the density of the target shale;

[0109] Parameter determination unit: used to determine the first physical property parameters of the target shale based on the well logging data of the target shale.

[0110] Optional, the parameter determination unit includes:

[0111] Clay content determination unit: used to determine the clay content of the target shale based on the extreme values ​​of the natural gamma logging curve of the target shale and the natural gamma logging curve of the pure sandstone section of the target formation. The target formation is the stratum in which the target shale is located.

[0112] Total organic carbon content determination unit: used to determine the total organic carbon content of the target shale based on the resistivity of the target shale and the resistivity of the non-hydrocarbon source rock mudstone layer in the target stratigraphic position;

[0113] Total porosity determination unit: used to determine the total porosity of the target shale based on the neutron density cross plot of the target shale; the neutron density cross plot of the target shale characterizes the total porosity of the target shale by establishing the relationship between the compensated neutrons of the target shale and the density of the target shale.

[0114] Optional, clay content determination unit, including:

[0115] Natural gamma relative value determination sub-unit: used to determine the natural gamma relative value of the target shale based on the natural gamma logging curve value of the target shale and the extreme value of the natural gamma logging curve of the pure sandstone section of the target formation;

[0116] Clay content determination sub-unit: used to determine the clay content of the target shale based on the relative natural gamma value and the empirical coefficient of stratigraphic age.

[0117] Optional. The reference shale core fracture pressure determination module 220 includes:

[0118] Second physical property parameter determination unit: used to determine the second physical property parameters of the reference shale core; the second physical property parameters include: clay content of the reference shale core, total organic carbon content of the reference shale core and total porosity of the reference shale core, and the second physical property parameters characterize the physical properties of the reference shale core;

[0119] Reference shale core fracture pressure determination unit: used to determine the fracture pressure of the reference shale core through fracture experiments; the fracture experiment is an experiment in which the reference shale core is continuously pressurized until the reference shale core fractures;

[0120] Fracture pressure model establishment unit: used to establish a fracture pressure model based on the fracture pressure of the reference shale core and the sum of the second physical property parameters of the reference shale core.

[0121] Optional, the fracture pressure model building element includes:

[0122] The rupture pressure model is expressed by the following equation:

[0123] P f =α(V SH +TOC+φ) β

[0124] Among them, P f To reference the fracture pressure of shale cores, V SH The reference shale core contains clay, TOC contains total organic carbon, φ contains total porosity, and α and β are constant values.

[0125] Optionally, the second physical characteristic parameter determination unit includes:

[0126] Nuclear magnetic resonance porosity determination subunit: used to measure the nuclear magnetic resonance porosity of a reference shale core using a nuclear magnetic resonance instrument;

[0127] Gas porosity determination subunit: used to determine gas porosity by introducing helium gas into a reference shale core and measuring the degree of helium escape.

[0128] Total porosity determination sub-unit of reference shale core: used to sum gas porosity and nuclear magnetic resonance porosity to obtain the total porosity of reference shale core.

[0129] The shale fracture pressure continuous depth evaluation device provided in this embodiment of the invention can execute the shale fracture pressure continuous depth evaluation method provided in any of the above embodiments of the invention, and has the corresponding functions and beneficial effects of executing the shale fracture pressure continuous depth evaluation method. For detailed process, please refer to the relevant operations of the shale fracture pressure continuous depth evaluation method in the foregoing embodiments.

[0130] Figure 7This is a schematic diagram of an electronic device used to implement the shale fracture pressure continuous depth evaluation method according to embodiments of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0131] like Figure 7 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 may also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0132] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0133] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, central processing unit (CPU), graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the shale fracture pressure continuous depth evaluation method.

[0134] In some embodiments, the shale fracture pressure continuous depth evaluation method can be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on electronic device 10 via ROM 12 and / or communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the shale fracture pressure continuous depth evaluation method described above can be performed. Alternatively, in other embodiments, processor 11 can be configured to perform the shale fracture pressure continuous depth evaluation method by any other suitable means (e.g., by means of firmware).

[0135] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0136] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0137] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0138] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0139] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0140] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through a communication network. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0141] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0142] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for evaluating the continuous depth of shale fracture pressure, characterized in that, include: Determine the primary physical property parameters of the target shale; The first physical characteristic parameter includes: the clay content of the target shale, the total organic carbon content of the target shale, and the total porosity of the target shale. The first physical characteristic parameter characterizes the physical characteristics of the target shale. The fracture pressure of the target shale is determined by a fracture pressure model based on the first physical property parameters of the target shale. The fracture pressure model is established based on the fracture pressure of a reference shale core and the second physical property parameters of the reference shale core, and is used to characterize the functional relationship between the fracture pressure of the reference shale core and the sum of the physical property parameters. The reference shale core and the target shale are located in the same geological area or in the same well.

2. The method according to claim 1, characterized in that, Determine the primary physical property parameters of the target shale, including: Acquire well logging data of the target shale; the well logging data of the target shale includes at least: the natural gamma logging curve value of the target shale, the resistivity of the target shale, the compensated neutron of the target shale, and the density of the target shale; The first physical property parameters of the target shale are determined based on the well logging data of the target shale.

3. The method according to claim 2, characterized in that, The first physical characteristic parameters of the target shale are determined based on the well logging data of the target shale, including: The clay content of the target shale is determined based on the extreme values ​​of the natural gamma logging curve of the target shale and the natural gamma logging curve of the pure sandstone section of the target formation. The target formation is the stratum in which the target shale is located. The total organic carbon content of the target shale is determined based on the resistivity of the target shale and the resistivity of the non-hydrocarbon source mudstone layer in the target stratigraphic position. The total porosity of the target shale is determined based on the neutron density cross plot of the target shale; the neutron density cross plot of the target shale characterizes the total porosity of the target shale by establishing the relationship between the compensated neutrons of the target shale and the density of the target shale.

4. The method according to claim 3, characterized in that, The clay content of the target shale is determined based on the extreme values ​​of the natural gamma-ray logging curves of the target shale and the natural gamma-ray logging curves of the pure sandstone section of the target formation, including: The relative value of natural gamma ray of the target shale is determined based on the natural gamma ray logging curve value of the target shale and the extreme value of the natural gamma ray logging curve of the pure sandstone section of the target formation. The clay content of the target shale is determined based on its natural gamma relative value and the empirical coefficient of stratigraphic age.

5. The method according to claim 1, characterized in that, The process of determining the rupture pressure model includes: Determine the second physical property parameters of the reference shale core; the second physical property parameters include: clay content, total organic carbon content and total porosity of the reference shale core, and the second physical property parameters characterize the physical properties of the reference shale core; The fracturing pressure of a reference shale core was determined by a fracturing experiment; the fracturing experiment was an experiment in which the reference shale core was continuously pressurized until the reference shale core fractured. A fracture pressure model is established based on the sum of the fracture pressure of the reference shale core and the second physical property parameter of the reference shale core.

6. The method according to claim 5, characterized in that, The rupture pressure model is expressed by the following equation: P f =α(V SH +TOC+φ) β Among them, P f To reference the fracture pressure of shale cores, V SH The reference shale core contains clay, TOC contains total organic carbon, φ contains total porosity, and α and β are constant values.

7. The method according to claim 5, characterized in that, Determine the second physical property parameters of the reference shale core, including: Nuclear magnetic resonance (NMR) measurements were performed on the reference shale core to obtain the NMR porosity. Helium gas was introduced into the reference shale core to determine the gas porosity based on the degree of helium escape. The total porosity of the reference shale core is obtained by summing the gas porosity and the nuclear magnetic resonance porosity.

8. A device for continuous depth evaluation of shale fracture pressure, characterized in that, include: The parameter determination module is used to determine the first physical property parameters of the target shale. The first physical characteristic parameter includes: the clay content of the target shale, the total organic carbon content of the target shale, and the total porosity of the target shale. The first physical characteristic parameter characterizes the physical characteristics of the target shale. The target shale fracture pressure determination module is used to determine the fracture pressure of the target shale based on the first physical property parameters of the target shale using a fracture pressure model. The fracture pressure model is established based on the fracture pressure of a reference shale core and the second physical property parameters of the reference shale core, and is used to characterize the functional relationship between the fracture pressure of the reference shale core and the sum of the physical property parameters. The reference shale core and the target shale are located in the same geological area or in the same well.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the shale fracture pressure continuous depth evaluation method according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions that cause a processor to execute the shale fracture pressure continuous depth evaluation method according to any one of claims 1-7.

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