Pore pressure determination method and device, storage medium and electronic equipment

Abstract

The invention relates to the field of petroleum engineering, and discloses a pore pressure determination method and device, a storage medium and electronic equipment. The method comprises the following steps: determining longitudinal wave time difference and transverse wave time difference of a rock debris sample, respectively performing overburden pressure correction on the longitudinal wave time difference and the transverse wave time difference, and determining a longitudinal wave and transverse wave ratio according to the corrected longitudinal wave time difference and transverse wave time difference; determining the content of each mineral in the rock debris sample and reconstructing the density content and the shale content; according to the density content, the shale content, the longitudinal wave time difference and the transverse wave time difference, the conversion relation between the dynamic and static elastic parameters is determined; determining vertical principal stress according to the density content; determining a relation between a longitudinal-transverse wave ratio and effective stress according to a conversion relation between the dynamic and static elastic parameters and preset static pressure test data; and determining a pore pressure determination model according to the vertical principal stress and the relation between the ratio of the longitudinal wave to the transverse wave and the effective stress. The invention discloses a while-drilling real-time pressure prediction method, and the real-time monitoring effect of the formation pressure is improved.

Description

Technical Field

[0001] The present application relates to the technical field of petroleum engineering, and particularly to a method and device for determining pore pressure, a storage medium, and an electronic device. Background Art

[0002] The purpose of the background art provided here is to generally give the background of the present application. The statements in this part only provide the background related to the present application and do not necessarily constitute the prior art.

[0003] With the deepening of the exploration and development process, the proportion of ultra-deep carbonate reservoirs discovered is increasing. For safe drilling, drilling engineers urgently need pre-monitoring of pore pressure.

[0004] Currently, a relatively mature method for pre-monitoring the pore pressure of shallow clastic rocks is the EATON method proposed based on the shale compaction principle. However, this method is not applicable to the chemical cementation of carbonate rocks for the compaction principle, and the effective stress method is commonly used to calculate the pore pressure. A relatively mature method is to calculate the formation pore pressure using logging data. However, the logging data can only be obtained after the drilling is completed, and it is difficult to use the pore pressure for pre-monitoring, with poor real-time performance and high costs.

[0005] Since mud logging data can provide primary data such as lithology, drilling parameters, and oil and gas components at the drilling site, and has the characteristics of high efficiency and low cost. Especially in recent years, with the development of acoustic wave measurement technology for cuttings logging, by measuring the longitudinal and transverse wave velocities of cuttings with a thickness greater than 1 mm, the longitudinal and transverse wave slowness can be obtained, which can be used to calculate rock mechanical parameters, and then calculate the pore pressure, providing a new method for pre-monitoring the pore pressure while drilling. However, in the actual application process, there are the following challenges: (1) The measurement velocity errors of the longitudinal and transverse waves of cuttings with different lithologies are different, increasing the iterative error of calculating rock mechanical parameters; (2) The acoustic wave measurement technology for cuttings is completed on the ground, with a large gap from the ultra-deep high-temperature and high-pressure environment; (3) Calculating rock mechanical parameters requires not only the longitudinal and transverse wave slowness but also parameters such as density and shale content, and other data are needed to cooperate to solve the problem.

[0006] Therefore, there is an urgent need to establish a new method for comprehensively using mud logging data to calculate pore pressure, so as to provide technical support for the efficient and fast drilling of ultra-deep carbonate rocks. Summary of the Invention

[0007] In view of the above problems, the present application provides a pore pressure determination method, apparatus, storage medium, and electronic device. By using the longitudinal and transverse wave velocities obtained through cuttings acoustic measurement technology, the reconstructed density and shale content from elemental logging, the rock mechanical parameters of ultra-deep carbonate rocks are calculated, and the pore pressure is calculated using the effective stress method, achieving the purpose of pre-monitoring deep carbonate rocks and providing a low-cost and fast method for obtaining pore pressure for drilling engineers.

[0008] In the first aspect of the present application, a pore pressure determination method is provided, and the method includes:

[0009] Determine the longitudinal wave slowness and transverse wave slowness of the cuttings sample;

[0010] Perform overburden pressure correction on the longitudinal wave slowness and the transverse wave slowness respectively through a preset acoustic overburden pressure correction model to obtain the corresponding corrected longitudinal wave slowness and transverse wave slowness, and determine the longitudinal-transverse wave ratio based on the corrected longitudinal wave slowness and transverse wave slowness;

[0011] Determine the content of each mineral in the cuttings sample, and reconstruct the density content and shale content based on the content of each mineral;

[0012] Determine the conversion relationship between the dynamic elastic parameters and the static elastic parameters based on the density content, the shale content, the longitudinal wave slowness, and the transverse wave slowness;

[0013] Determine the vertical principal stress based on the density content;

[0014] Determine the relationship between the longitudinal-transverse wave ratio and the effective stress based on the conversion relationship between the dynamic elastic parameters and the static elastic parameters and the preset hydrostatic test data;

[0015] Determine a pore pressure determination model based on the vertical principal stress and the relationship between the longitudinal-transverse wave ratio and the effective stress, and determine the pore pressure of the cuttings sample through the pore pressure determination model.

[0016] Further, the determining the longitudinal wave slowness and transverse wave slowness of the cuttings sample includes:

[0017] Measure the longitudinal wave velocity and transverse wave velocity of the cuttings sample through a controlled cuttings acoustic measuring instrument to determine the longitudinal wave slowness and transverse wave slowness of the cuttings sample.

[0018] Further, the manner of creating the preset acoustic overburden pressure correction model includes:

[0019] Obtain the high-temperature and high-pressure cuttings acoustic characteristics of the cuttings sample, and create the preset acoustic overburden pressure correction model based on the high-temperature and high-pressure cuttings acoustic characteristics.

[0020] Further, determining the vertical principal stress according to the density content includes:

[0021] Determining the vertical principal stress by means of piecewise integration according to the density content.

[0022] Further, the expression of the piecewise integration includes:

[0023]

[0024] where σ v is the vertical principal stress, h1 and h2 are the initial depth and the termination depth respectively, ρ0 is the overburden equivalent density at the initial well depth, and ρ(h) is the density content varying with depth.

[0025] Further, the relationship between the P-wave to S-wave ratio and the effective stress includes:

[0026]

[0027] where σ e is the effective stress, K and K1 are both constants, DTS is the shear wave slowness, and DTC is the compressional wave slowness.

[0028] Further, the pore pressure determination model includes:

[0029]

[0030] where P p is the pore pressure, σ v is the vertical principal stress, K and K1 are both constants, DTS is the shear wave slowness, and DTC is the compressional wave slowness.

[0031] In the second aspect of the present application, a pore pressure determination device is provided, and the device includes:

[0032] A P-wave and S-wave slowness determination module, configured to determine the compressional wave slowness and the shear wave slowness of a cuttings sample;

[0033] A correction module, configured to perform overburden correction on the compressional wave slowness and the shear wave slowness respectively through a preset acoustic overburden correction model, obtain the corresponding corrected compressional wave slowness and shear wave slowness, and determine the P-wave to S-wave ratio according to the corrected compressional wave slowness and shear wave slowness;

[0034] A mineral content determination module, configured to determine the content of each mineral in the cuttings sample, and reconstruct the density content and the shale content according to the content of each mineral;

[0035] A conversion relationship determination module, configured to determine the conversion relationship between the dynamic elastic parameter and the static elastic parameter according to the density content, the shale content, the compressional wave slowness, and the shear wave slowness.

[0036] A vertical principal stress determination module for determining the vertical principal stress according to the density content;

[0037] A relationship determination module between the P-wave to S-wave ratio and the effective stress for determining the relationship between the P-wave to S-wave ratio and the effective stress according to the conversion relationship between the dynamic elastic parameters and the static elastic parameters and the preset static pressure test data;

[0038] A pore pressure determination module for determining a pore pressure determination model according to the vertical principal stress and the relationship between the P-wave to S-wave ratio and the effective stress, and determining the pore pressure of the cuttings sample through the pore pressure determination model.

[0039] In a third aspect of the present application, a computer-readable storage medium is provided. The computer program stored in the computer-readable storage medium can be executed by one or more processors to implement the steps of the method as described above.

[0040] In a fourth aspect of the present application, an electronic device is provided, including a memory and one or more processors. A computer program is stored on the memory, and the memory and the one or more processors are communicatively connected to each other. When the computer program is executed by the one or more processors, the steps of the method as described above are implemented.

[0041] Compared with the prior art, the advantages or beneficial effects of the technical solution of the present application include:

[0042] The present application obtains the P-wave and S-wave velocities through a cuttings logging acoustic wave instrument, reconstructs the density by using element logging, calculates the shale content, combines the on-site static pressure test experimental data to establish an effective stress model, and finally calculates and obtains the pore pressure, forming a set of real-time pressure prediction method while drilling for deep carbonate rock formations, improving the real-time pre-monitoring effect of formation pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0044] In addition, it should be noted that for the sake of convenience of description, only the parts related to the present disclosure are shown in the drawings. The specification drawings constituting a part of the present application are used to provide a further understanding of the present application. The schematic embodiments and descriptions in the present application are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0045] Figure 1 Flow chart of a pore pressure determination method provided by an embodiment of the present application;

[0046] Figure 2 Flow chart of another pore pressure determination method provided by an embodiment of the present application;

[0047] Figure 3 Schematic diagram of the result of reconstructing the density curve of Well SHX using element logging data provided by an embodiment of the present application;

[0048] Figure 4 Schematic diagram of the relationship between effective stress and the ratio of longitudinal and transverse wave velocities provided by an embodiment of the present application;

[0049] Figure 5 Schematic diagram of the result of calculating pore pressure using cuttings acoustic logging data provided by an embodiment of the present application. Detailed implementation manners

[0050] The following will describe in detail the implementation manners of the present application in conjunction with the accompanying drawings and embodiments, so as to fully understand how the present application uses technical means to solve technical problems and achieve the corresponding technical effects and implement them accordingly. Each feature in the embodiments of the present application can be combined with each other without conflict, and the formed technical solutions are all within the protection scope of the present application.

[0051] It should be clear that the following described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts fall within the protection scope of the present application.

[0052] Embodiment 1

[0053] This embodiment provides a pore pressure determination method, which can be used to calculate the pore pressure of ultra-deep carbonate rocks. Figure 1 Flow chart of a pore pressure determination method provided by an embodiment of the present application, as Figure 1 shown, the method disclosed in this embodiment includes the following steps:

[0054] Step 110: Determine the longitudinal wave travel time and transverse wave travel time of the cuttings sample.

[0055] As an example, the determining the longitudinal wave travel time and transverse wave travel time of the cuttings sample includes:

[0056] Measure the longitudinal wave velocity and transverse wave velocity of the cuttings sample by controlling a cuttings acoustic measuring instrument to determine the longitudinal wave travel time and transverse wave travel time of the cuttings sample.

[0057] Step 120: Perform overburden correction on the longitudinal wave slowness and the shear wave slowness respectively through a preset acoustic wave overburden correction model to obtain the corresponding corrected longitudinal wave slowness and shear wave slowness, and determine the longitudinal-to-shear wave ratio based on the corrected longitudinal wave slowness and shear wave slowness.

[0058] As an example, the method for creating the preset acoustic wave overburden correction model includes:

[0059] Obtain the acoustic wave characteristics of the cuttings sample under high temperature and high pressure, and create the preset acoustic wave overburden correction model according to the acoustic wave characteristics of the cuttings sample under high temperature and high pressure.

[0060] Optionally, establish a longitudinal and shear wave slowness overburden correction model through measuring the acoustic wave characteristics of cuttings under high temperature and high pressure, and use the longitudinal and shear wave slowness overburden correction model as the preset acoustic wave overburden correction model.

[0061] Step 130: Determine the content of each mineral in the cuttings sample, and reconstruct the density content and shale content according to the content of each mineral.

[0062] Specifically, in the deep carbonate rock section, the changes of elements such as Mg, Ca, Cl, and Na in the element logging are obvious, and the results of element calculation of minerals can clearly depict the changes in the content of the main framework minerals in carbonate rocks (dolomite, limestone, rock salt, etc.). According to the rock physics model, the formation density value can be calculated by forward modeling from the mineral content:

[0063] DENC = (VSH * a * 2.55 + SAND * 2.65 + LIME * 2.71 + XCS * 2.67) / Wt

[0064] In the above formula, VSH is the shale content; SAND is the sandstone content; LIME is the limestone content, XCS is the plagioclase content, and Wt is the total mineral content, with the unit of %.

[0065] Step 140: Determine the conversion relationship between the dynamic elastic parameters and the static elastic parameters according to the density content, the shale content, the longitudinal wave slowness, and the shear wave slowness.

[0066] Optionally, calculate the rock mechanics parameters through the longitudinal and shear wave slowness, density, and shale content after overburden correction, and establish the dynamic-static relationship according to the rock mechanics experiment:

[0067] Poisson's ratio:

[0068] Young's modulus:

[0069] In the above formula, DTS and DTC respectively refer to the formation shear wave slowness and longitudinal wave slowness, μs / ft; DEN is the formation bulk density, g / cm 3 .

[0070] Through the synchronous test of dynamic and static elastic parameters of indoor rock mechanics, the conversion relationship between dynamic and static elastic parameters is established as:

[0071] SPOIS = aPOIS + b

[0072] SYMOD = cYMOD + d

[0073] Among them, a, b, c, and d are all constants.

[0074] Step 150: Determine the vertical principal stress according to the density content.

[0075] Optionally, the overburden pressure (vertical principal stress) of the formation can be obtained by piecewise integration using density data.

[0076] As an example, the determining of the vertical principal stress according to the density content includes:

[0077] Determine the vertical principal stress by piecewise integration according to the density content.

[0078] As an example, the expression of the piecewise integration includes:

[0079]

[0080] Among them, σ v is the vertical principal stress, h1 and h2 are the initial depth and the termination depth respectively, ρ0 is the equivalent overburden density at the initial well depth, and ρ(h) is the density content varying with depth.

[0081] Step 160: Determine the relationship between the P-wave to S-wave ratio and the effective stress according to the conversion relationship between the dynamic elastic parameter and the static elastic parameter and the preset static pressure test data.

[0082] As an example, the relationship between the P-wave to S-wave ratio and the effective stress includes:

[0083]

[0084] Among them, σ e is the effective stress, K and K1 are both constants, DTS is the shear wave slowness, and DTC is the compressional wave slowness.

[0085] Step 170: Determine the pore pressure determination model according to the vertical principal stress and the relationship between the P-wave to S-wave ratio and the effective stress, and determine the pore pressure of the cuttings sample through the pore pressure determination model.

[0086] Optionally, according to the effective stress method σ e = σ v - αPp , a pore pressure determination model can be obtained.

[0087] As an example, the pore pressure determination model includes:

[0088]

[0089] Wherein, P p is the pore pressure, σ v is the vertical principal stress, both K and K1 are constants, DTS is the shear wave time difference, and DTC is the compressional wave time difference.

[0090] For the convenience of understanding the technical solution of the present application, reference can also be made to Figure 2 .

[0091] In this embodiment, a new method for calculating the pore pressure of deep carbonate rock formations using cuttings acoustic logging data is disclosed. By using a cuttings logging acoustic instrument to obtain the compressional and shear wave velocities, reconstructing the density using element logging, calculating the shale content, and combining the on-site hydrostatic pressure test experimental data to establish an effective stress model, the pore pressure is finally calculated, forming a set of real-time pressure prediction methods for deep carbonate rock formations while drilling, improving the real-time pre-monitoring effect of formation pressure.

[0092] Embodiment Two

[0093] Based on Embodiment One, this embodiment further explains and illustrates the pore pressure determination method disclosed in Embodiment One by way of example.

[0094] In this embodiment, taking a deep carbonate rock in the Tarim Basin as an example, for the SHX well with a well depth of 8600 meters, the pore pressure can be determined by the method disclosed in the present application, and the error between the calculated pore pressure and the logging data is less than 10%. Specifically, the following steps may be included:

[0095] First step, select cuttings with good particle size downhole for sample preparation, grind the end face flat, and measure the compressional and shear wave velocities using cuttings acoustic measurement. The measurement results are as shown in Figure 5 the 3rd and 5th traces, showing a certain gap from the compressional and shear wave time differences measured by logging.

[0096] Second step, establish a compressional and shear wave time difference overburden correction model through high-temperature and high-pressure cuttings acoustic property measurement. Figure 5 The 4th and 6th traces in

[0097] are the compressional and shear wave time differences after overburden correction, with an error less than 10% from the compressional and shear wave time differences measured by logging.

[0098] In element logging, the changes of elements such as Mg, Ca, Cl, and Na are obvious in the deep carbonate rock section. The results of element-based mineral calculations can clearly depict the changes in the contents of the main framework minerals in carbonate rocks (dolomite, limestone, rock salt, etc.). According to the rock physics model, the formation density value can be forward calculated from the mineral content:

[0099] DENC = (VSH * a * 2.55 + SAND * 2.65 + LIME * 2.71 + XCS * 2.67) / Wt

[0100] In the above formula, VSH is the shale content; SAND is the sandstone content; LIME is the limestone content, XCS is the plagioclase content, and Wt is the total mineral content, all in %. The results of reconstructing the density curve of Well SHX using element logging data can be referred to Figure 3 .

[0101] Fourth step, calculate the rock mechanical parameters through the shear wave slowness, compressional wave slowness, density, and shale content after overburden correction, and establish the dynamic-static relationship based on rock mechanics experiments. Among them,

[0102] Poisson's ratio:

[0103] Young's modulus:

[0104] In the above formula, DTS and DTC refer to the shear wave slowness and compressional wave slowness of the formation, in μs / ft; DEN is the formation bulk density, in g / cm 3 .

[0105] Furthermore, through the synchronous test of dynamic and static elastic parameters of indoor rock mechanics, the conversion relationship between dynamic elastic parameters and static elastic parameters is established as:

[0106] SPOIS = aPOIS + b

[0107] SYMOD = cYMOD + d

[0108] Among them, a, b, c, and d in the above formula are all constants, and the specific values can be obtained through actual experimental data.

[0109] Fifth step, the overburden pressure (vertical principal stress) of the formation can be obtained by piecewise integration using density data. Among them, the expression of piecewise integration can include:

[0110]

[0111] Among them, σ v is the vertical principal stress, h1 and h2 are the initial depth and the termination depth respectively, ρ0 is the overburden equivalent density at the initial well depth, and ρ(h) is the density value varying with depth.

[0112] Step 6: Using the static pressure test data of Well SHX2, establish the relationship between the shear-wave to compressional-wave ratio and the effective stress (i.e., the effective stress model):

[0113]

[0114] where σ e is the effective stress, both K and K1 are constants, DTS is the shear-wave travel time difference, and DTC is the compressional-wave travel time difference. The relationship between the effective stress and the shear-wave to compressional-wave velocity ratio can be referred to Figure 4 .

[0115] Step 7: According to the effective stress method σ e = σ v - αP p , the pore pressure determination model can be obtained.

[0116] Normally, the value range of α is between 0.8 and 1. In some cases, the value of α can be taken as 1.

[0117] As an example, the pore pressure determination model includes:

[0118]

[0119] where P p is the pore pressure, σ v is the vertical principal stress, both K and K1 are constants, DTS is the shear-wave travel time difference, and DTC is the compressional-wave travel time difference.

[0120] Preferably, the values of K and K1 can be taken as 49.978 and 0.3052 respectively.

[0121] Furthermore, referring to Figure 5 , Figure 5 is the result of calculating the pore pressure using the cuttings acoustic logging data. Among them, the first track is the depth track, the second track is the GR (natural gamma ray of well logging), and DENC is the density curve reconstructed by elemental logging; the third and fifth tracks are the shear-wave and compressional-wave travel time differences obtained by the cuttings acoustic measuring instrument and the shear-wave and compressional-wave travel time differences measured by well logging respectively; the fourth and sixth tracks are the cuttings acoustic shear-wave and compressional-wave data after overburden correction; the pink and blue scatter points in the seventh and eighth tracks (all the points in the seventh track are pink scatter points. In the eighth track: all the points below the depth of 7750 are blue scatter points; above the depth of 7750: the points on the left are blue scatter points, and the points on the right are pink scatter points) are the Young's modulus and Poisson's ratio calculated using the shear-wave and compressional-wave travel time differences after overburden correction and the density reconstructed by elemental logging respectively, and the continuous curve is the elastic parameters calculated using the shear-wave and compressional-wave travel time differences measured by well logging data; the ninth track is the vertical principal stress calculated by the curve and scatter points of well logging; the tenth track is the pore pressure calculated by the curve and scatter points of well logging data.

[0122] According to Figure 5 , it can be seen from the comparison results that, compared with the elastic parameters and pore pressure calculated from well logging data, the errors of Young's modulus and Poisson's ratio calculated using mud logging data are between 2.96 - 25.89%, and the pore pressure error is between 4.64 - 6.98%, indicating that this method has high practicability and reliability.

[0123] Embodiment III

[0124] This embodiment provides a pore pressure determination device. The device embodiment of this embodiment can be used to execute the method embodiment of the present application. For details not disclosed in the device embodiment of this embodiment, please refer to the method embodiment of the present application. The device disclosed in this embodiment includes:

[0125] A longitudinal and transverse wave slowness determination module, configured to determine the longitudinal wave slowness and transverse wave slowness of a cuttings sample;

[0126] A correction module, configured to perform overburden pressure correction on the longitudinal wave slowness and the transverse wave slowness respectively through a preset acoustic overburden pressure correction model, obtain the corresponding corrected longitudinal wave slowness and transverse wave slowness, and determine the longitudinal and transverse wave ratio according to the corrected longitudinal wave slowness and transverse wave slowness;

[0127] A mineral content determination module, configured to determine the content of each mineral in the cuttings sample, and reconstruct the density content and shale content according to the content of each mineral;

[0128] A conversion relationship determination module, configured to determine the conversion relationship between dynamic elastic parameters and static elastic parameters according to the density content, the shale content, the longitudinal wave slowness, and the transverse wave slowness;

[0129] A vertical principal stress determination module, configured to determine the vertical principal stress according to the density content;

[0130] A longitudinal and transverse wave ratio and effective stress relationship determination module, configured to determine the relationship between the longitudinal and transverse wave ratio and the effective stress according to the conversion relationship between the dynamic elastic parameters and the static elastic parameters and preset hydrostatic test data;

[0131] A pore pressure determination module, configured to determine a pore pressure determination model according to the vertical principal stress and the relationship between the longitudinal and transverse wave ratio and the effective stress, and determine the pore pressure of the cuttings sample through the pore pressure determination model.

[0132] In some embodiments, the longitudinal and transverse wave slowness determination module is configured to measure the longitudinal wave velocity and transverse wave velocity of the cuttings sample by controlling a cuttings acoustic measuring instrument, so as to determine the longitudinal wave slowness and transverse wave slowness of the cuttings sample.

[0133] In some embodiments, the calibration module includes a model creation unit for obtaining the acoustic properties of cuttings samples under high temperature and high pressure and creating the preset acoustic overburden pressure correction model based on the acoustic properties of cuttings samples under high temperature and high pressure.

[0134] In some embodiments, the vertical principal stress determination module is configured to determine the vertical principal stress by means of piecewise integration according to the density data.

[0135] In some embodiments, the expression of the piecewise integration includes:

[0136]

[0137] where σ v is the vertical principal stress, h1 and h2 are the initial depth and the termination depth respectively, ρ0 is the equivalent overburden density at the initial well depth, and ρ(h) is the density value varying with depth.

[0138] In some embodiments, the relationship between the shear-wave to compressional-wave ratio and the effective stress includes:

[0139]

[0140] where σ e is the effective stress, K and K1 are both constants, DTS is the shear-wave travel time difference, and DTC is the compressional-wave travel time difference.

[0141] In some embodiments, the pore pressure determination model includes:

[0142]

[0143] where P p is the pore pressure, σ v is the vertical principal stress, K and K1 are both constants, DTS is the shear-wave travel time difference, and DTC is the compressional-wave travel time difference.

[0144] Those skilled in the art can understand that the structures shown in this device do not constitute a limitation on the device of the embodiments of the present application, and may include more or fewer modules / units than shown in the figure, or combine some modules / units, or arrange different modules / units differently.

[0145] Those skilled in the art should understand that the various modules or steps of the present application described above can be implemented using a general-purpose computing device. They can be concentrated on a single computing device or distributed across a network composed of multiple computing devices. Optionally, they can be implemented using program code executable by a computing device. Thus, they can be stored in a storage device and executed by the computing device. And in some cases, the steps shown or described can be executed in a different order than here, or they can be separately fabricated into individual integrated circuit modules, or multiple modules or steps among them can be fabricated into a single integrated circuit module for implementation.

[0146] Embodiment 4

[0147] This embodiment provides a computer-readable storage medium. A computer program is stored in the computer-readable storage medium. When the computer program is executed by a processor, the method steps in the foregoing method embodiments can be implemented, and this embodiment will not be repeated here.

[0148] Among them, the computer-readable storage medium may also separately include a computer program, a data file, a data structure, etc., or include a combination thereof. The computer-readable storage medium or the computer program can be specifically designed and understood by those skilled in the computer software field, or the computer-readable storage medium may be well-known and available to those skilled in the computer software field. Examples of computer-readable storage media include: magnetic media, such as hard disks, floppy disks, and magnetic tapes; optical media, such as CD-ROM discs and DVDs; magneto-optical media, such as optical discs; and hardware devices specifically configured to store and execute computer programs, such as read-only memory (ROM), random access memory (RAM), flash memory; or servers, app application stores, etc. Examples of computer programs include machine code (e.g., code generated by a compiler) and files containing high-level code that can be executed by a computer by using an interpreter. The described hardware devices can be configured to serve as one or more software modules to perform the operations and methods described above, and vice versa. Additionally, the computer-readable storage medium can be distributed across a networked computer system and can store and execute program code or computer programs in a decentralized manner.

[0149] Embodiment 5

[0150] This embodiment provides a computer program product. The computer program product includes a computer program or instruction. When the computer program or instruction is executed by a processor, all or part of the steps of the method in the foregoing method embodiments are implemented, and this embodiment will not be repeated here.

[0151] Further, the computer program product may include one or more computer-executable components configured to execute the embodiments when the program is running; the computer program product may also include a computer program tangibly embodied on a computer-readable medium, the computer program including program code for performing any of the methods in the embodiments of the present disclosure. In such an embodiment, the computer program may be downloaded and installed from a network through a communication part, and / or installed from a removable medium.

[0152] Embodiment Six

[0153] This embodiment provides an electronic device, which may include: one or more processors, a memory, a multimedia component, an input / output (I / O) interface, and a communication component.

[0154] Wherein, the one or more processors are configured to execute all or part of the steps in the foregoing method embodiments. The memory is used to store various types of data, which may include, for example, instructions of any application program or method in the electronic device, as well as application-related data.

[0155] The one or more processors may be implemented by an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller, a microprocessor, or other electronic components, and are configured to execute the methods in the foregoing method embodiments.

[0156] The memory can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disc.

[0157] The multimedia component may include a screen and an audio component. The screen may be a touch screen, and the audio component is used to output and / or input audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signals may be further stored in the memory or transmitted via the communication component. The audio component further includes at least one speaker for outputting audio signals.

[0158] The I / O interface provides an interface between one or more processors and other interface modules, and the other interface modules may be a keyboard, a mouse, buttons, etc. These buttons may be virtual buttons or physical buttons.

[0159] The communication component is used for wired or wireless communication between the electronic device and other devices. Wired communication includes communication via a network port, a serial port, etc.; wireless communication includes Wi-Fi, Bluetooth, near field communication (NFC), 2G, 3G, 4G, 5G, or a combination of one or more of them.

[0160] It should also be understood that the methods or apparatuses disclosed in the embodiments provided in this application can also be implemented in other ways. The method or apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions, and operations of the methods and apparatuses according to multiple embodiments of this application. In this regard, each block in the flowchart or block diagram may represent a module, a computer program segment, or a part of a computer program. A module, a computer program segment, or a part of a computer program contains one or more computer programs for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order from that marked in the accompanying drawings. In fact, they may also be executed substantially in parallel, and sometimes they may be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, as well as the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and a computer program.

[0161] In this application, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the process, method, apparatus or device comprising the element; if there is a description of "first", "second", etc., it is only for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features or implicitly specifying the sequence of the indicated technical features; in the description of this application, unless otherwise specified, the meaning of the terms "a plurality", "many" is at least two; if there is a description of a server, it should be noted that the server can be an independent physical server or terminal, or a server cluster composed of multiple physical servers, and can be a cloud server capable of providing basic cloud computing services such as cloud servers, cloud databases, cloud storage and CDN; in this application, if there is a description of a smart terminal or mobile device, it should be noted that the smart terminal or mobile device can be a mobile phone, tablet computer, smart watch, netbook, wearable electronic device, personal digital assistant (PDA), augmented reality device (AR), virtual reality device (VR), smart TV, smart speaker, personal computer (PC), etc., but is not limited thereto, and this application does not make special limitations on the specific form of the smart terminal or mobile device.

[0162] Finally, it should be noted that in the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "one example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0163] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are all exemplary. The content described above is only an implementation manner adopted for the convenience of understanding the present application, and is not used to limit the present application. Any person skilled in the art within the technical field to which the present application pertains may make any modifications and changes in the form of implementation and details without departing from the spirit and scope disclosed by the present application. However, the protection scope of the present application shall still be subject to the scope defined by the appended claims.

Claims

1. A method for determining pore pressure, characterized in that, The method includes: Determining the longitudinal wave slowness and the shear wave slowness of the cuttings sample; Performing overburden correction on the longitudinal wave slowness and the shear wave slowness respectively through a preset acoustic overburden correction model to obtain the corresponding corrected longitudinal wave slowness and shear wave slowness, and determining the longitudinal-to-shear wave ratio according to the corrected longitudinal wave slowness and shear wave slowness; Determining the content of each mineral in the cuttings sample, and reconstructing the density content and the shale content according to the content of each mineral; Determining the conversion relationship between the dynamic elastic parameters and the static elastic parameters according to the density content, the shale content, the longitudinal wave slowness and the shear wave slowness; Determining the vertical principal stress according to the density content; Determining the relationship between the longitudinal-to-shear wave ratio and the effective stress according to the conversion relationship between the dynamic elastic parameters and the static elastic parameters and the preset hydrostatic pressure test data; Determining a pore pressure determination model according to the vertical principal stress and the relationship between the longitudinal-to-shear wave ratio and the effective stress, and determining the pore pressure of the cuttings sample through the pore pressure determination model.

2. The pore pressure determination method according to claim 1, wherein The determining the longitudinal wave slowness and the shear wave slowness of the cuttings sample includes: Measuring the longitudinal wave velocity and the shear wave velocity of the cuttings sample by controlling a cuttings acoustic measuring instrument to determine the longitudinal wave slowness and the shear wave slowness of the cuttings sample.

3. The pore pressure determination method according to claim 1, characterized in that, The manner of creating the preset acoustic overburden correction model includes: Obtaining the acoustic characteristics of the cuttings sample under high temperature and high pressure, and creating the preset acoustic overburden correction model according to the acoustic characteristics of the cuttings sample under high temperature and high pressure.

4. The pore pressure determination method according to claim 1, characterized in that The determining the vertical principal stress according to the density content includes: Determining the vertical principal stress by means of piecewise integration according to the density content.

5. The pore pressure determination method according to claim 4, wherein, The expression of the piecewise integration includes: Among them, σ v is the vertical principal stress, h1 and h2 are the initial depth and the termination depth respectively, ρ0 is the equivalent overburden density at the initial well depth, and ρ(h) is the density content varying with depth.

6. The pore pressure determination method according to claim 1, characterized in that, The relationship between the longitudinal-to-shear wave ratio and the effective stress includes: Among them, σ e is the effective stress, both K and K1 are constants, DTS is the shear wave travel time difference, and DTC is the compressional wave travel time difference.

7. The pore pressure determination method according to claim 1, characterized in that, The pore pressure determination model includes: where P p is the pore pressure, σ v is the vertical principal stress, K and K1 are both constants, DTS is the shear wave travel time difference, and DTC is the compressional wave travel time difference.

8. A pore pressure determination device, characterized in that, Including: A longitudinal and shear wave slowness determination module, configured to determine the longitudinal wave slowness and the shear wave slowness of the cuttings sample; A correction module, configured to perform overburden correction on the longitudinal wave slowness and the shear wave slowness respectively through a preset acoustic overburden correction model to obtain the corresponding corrected longitudinal wave slowness and shear wave slowness, and determine the longitudinal-to-shear wave ratio according to the corrected longitudinal wave slowness and shear wave slowness; A mineral content determination module, configured to determine the content of each mineral in the cuttings sample, and reconstruct the density content and the shale content according to the content of each mineral; A conversion relationship determination module, configured to determine the conversion relationship between the dynamic elastic parameters and the static elastic parameters according to the density content, the shale content, the longitudinal wave slowness and the shear wave slowness; A vertical principal stress determination module, configured to determine the vertical principal stress according to the density content; A longitudinal-to-shear wave ratio and effective stress relationship determination module, configured to determine the relationship between the longitudinal-to-shear wave ratio and the effective stress according to the conversion relationship between the dynamic elastic parameters and the static elastic parameters and the preset hydrostatic pressure test data; A pore pressure determination module, configured to determine a pore pressure determination model according to the vertical principal stress and the relationship between the longitudinal-to-shear wave ratio and the effective stress, and determine the pore pressure of the cuttings sample through the pore pressure determination model.

9. A computer-readable storage medium, characterized in that, The computer program stored in the computer-readable storage medium, when executed by one or more processors, implements the pore pressure determination method according to any one of claims 1 to 7.

10. An electronic device, characterized in that, It includes a memory and a processor. A computer program is stored on the memory. When the computer program is executed by the processor, it implements the pore pressure determination method according to any one of claims 1 to 7.

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