A method, device and equipment for calculating longitudinal and transverse wave combined formation pressure

Abstract

This application provides a method, apparatus, and equipment for calculating combined P-wave and S-wave formation pressure, belonging to the field of geophysical exploration. The method includes the following steps: acquiring P-wave and S-wave borehole seismic data; preprocessing the P-wave and S-wave borehole seismic data; based on the preprocessed borehole seismic data, dividing the measured formation into layers and calculating the P-wave and S-wave velocities of each layer; acquiring well logging density data; processing the well logging density data to obtain density data for each layer; determining the in-situ stress of the target formation in each layer based on the P-wave, S-wave, and density data of each layer; determining the overlying strata pressure at the target formation based on the average density of the overlying strata; and determining the formation pressure of the target formation based on the overlying strata pressure and in-situ stress. This application aims to solve the problem of accurately calculating formation pressure.

Description

Technical Field

[0001] This application relates to the field of geophysical exploration, and more specifically, to a method, apparatus, and equipment for calculating combined P-wave and S-wave formation pressure. Background Technology

[0002] The detection and prediction of formation pressure has long been a challenge in the field of geophysics. Accurately calculating formation pressure is a means of ensuring safe drilling operations and has been an important goal pursued by geophysicists at home and abroad for many years.

[0003] Currently, there are two main categories of methods for pressure calculation using geophysical data:

[0004] The first category of methods uses well logging data for calculation, mainly including: sonic transit time method, array method, equivalent depth method, Eaton method, etc. These well logging methods have solved the problem of formation pressure calculation to a certain extent, but existing technologies still have some limitations, such as: not applicable to non-mudstone formations, not applicable to abnormal pressure mechanisms other than unbalanced compaction, etc.

[0005] The second type of method uses seismic data for calculation. This mainly involves obtaining formation velocity and then using empirical formulas to calculate formation pressure. However, this method also has certain errors. First, many factors influence formation velocity, and the velocity itself has errors and relatively low resolution. Directly calculating formation pore pressure from the velocity without describing or making appropriate assumptions about other influencing factors can easily lead to significant errors. Second, the velocity itself has errors and relatively low resolution. These errors include both random and systematic errors, which will affect the accuracy of pressure prediction results and depth. Summary of the Invention

[0006] This application provides a method, apparatus, and equipment for calculating combined P-wave and S-wave formation pressure, aiming to solve the problem of accurately calculating formation pressure.

[0007] In a first aspect, embodiments of this application provide a method for calculating combined P-wave and S-wave formation pressure, comprising the following steps:

[0008] Acquire P-wave and S-wave seismic data from wells, and preprocess the P-wave and S-wave seismic data from wells.

[0009] Based on the preprocessed well seismic data, the measured strata were divided into layers, and the P-wave velocity and S-wave velocity of each measured stratum were calculated.

[0010] Acquire well logging density data, process the well logging density data, and obtain density data for each measured formation layer;

[0011] Based on the P-wave velocity, S-wave velocity and density data of each measured stratum, the geostress of the stratum to be measured in each measured stratum is determined.

[0012] The pressure of the overlying strata at the stratum to be measured is determined based on the average density of the overlying strata.

[0013] The formation pressure of the stratum to be measured is determined based on the pressure of the overlying strata and the geostress at the stratum to be measured.

[0014] Optionally, acquiring the well seismic data of P-waves and S-waves includes:

[0015] An excitation point is set at the wellhead of the observation well, and the excitation point is the location of the seismic source that meets the zero well-source distance VSP acquisition condition;

[0016] A surface P-wave source and a surface S-wave source are set at the excitation point and excited to generate P-waves and S-waves.

[0017] A three-component geophone was used to receive P-wave and S-wave seismic data in the observation well.

[0018] Optionally, the preprocessing includes at least one of the following: three-component rotation processing, random noise suppression processing, amplitude compensation processing, and deconvolution processing.

[0019] Optionally, the processing of the well logging density data includes at least one of: abnormal noise removal, data depth range adjustment, and data resampling.

[0020] Optionally, the calculation of the P-wave velocity and S-wave velocity for each measured stratum includes:

[0021] Based on the preprocessed well seismic data, the first arrival of the shear wave and the first arrival of the p-wave are picked up at the same phase on the p-wave and shear wave respectively. The first arrival is picked up at the position of the peak maximum.

[0022] Based on the first arrival of the shear wave and the first arrival of the longitudinal wave, the longitudinal wave velocity and the shear wave velocity of each measured stratum are obtained.

[0023] Optionally, determining the geostress of the stratum to be measured in each measurement stratum based on the P-wave velocity, S-wave velocity, and density data of each measurement stratum includes the following steps:

[0024] A. Using the depth sampling sequence number collected by VSP, the measured strata are divided into layers. The depth sampling sequence numbers are recorded from top to bottom as 0, 1, 2, 3...i, where i is the depth sampling sequence number of the stratum to be measured.

[0025] B. Using a pressure gauge, the ground stress at layer 0 is obtained and used as a reference point, denoted as σ0;

[0026] C, based on σ0, calculate the geostress of layer σ1 using the following formula;

[0027]

[0028] In the formula, x is the depth sampling number of the target stratum, x = 0, 1, 2, 3…i; σ x The geostress of the stratum with depth sampling number x is σ. x-1 The geostress of the layer above the stratum with depth sampling number x is Δ. x This is a function representing the ratio of geostress between the stratum with depth sampling number x and the stratum with depth sampling number x-1.

[0029] in,

[0030] In the formula, ρ x-1 ρ represents the formation density of the stratum with depth sampling number x-1. x The formation density of the stratum with depth sampling number x-1; The P-wave velocity of the formation with depth sampling number x-1; The shear wave velocity of the formation with depth sampling number x-1; The P-wave velocity of the formation with depth sampling number x; The shear wave velocity of the formation with depth sampling number x;

[0031] D. Repeat step C until x = i, and output the geostress σ of the stratum i to be measured. i .

[0032] Optionally, determining the overlying stratum pressure at the stratum to be measured based on the average density of the overlying strata of the measured stratum includes:

[0033] The pressure of the overlying strata at the stratum to be measured is determined by the following formula:

[0034]

[0035] In the formula, P Oi The pressure of the overlying strata of the target stratum i; H represents the average density of the overlying rock strata. i denoted as , where is the depth of the target stratum i; and g is the gravitational acceleration.

[0036] Secondly, a combined P-wave and S-wave formation pressure calculation device includes:

[0037] The well-drilled seismic data acquisition module is used to acquire well-drilled seismic data of P-waves and S-waves, and to preprocess the well-drilled seismic data of P-waves and S-waves.

[0038] The formation velocity calculation module, based on preprocessed well seismic data, divides the measured formation into layers and calculates the P-wave velocity and S-wave velocity of each layer.

[0039] The density data acquisition module processes the well logging density data to obtain the density data for each measured formation.

[0040] The in-situ stress determination module determines the in-situ stress of the stratum to be measured in each stratum based on the P-wave velocity, S-wave velocity and density data of each measured stratum.

[0041] The overlying strata pressure determination module determines the overlying strata pressure at the stratum to be measured based on the average density of the overlying strata of the measured stratum.

[0042] The formation pressure determination module determines the formation pressure of the formation to be measured based on the pressure of the overlying strata and the geostress at the formation to be measured.

[0043] Thirdly, an electronic device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of the method for calculating combined P-wave and S-wave formation pressure as described in the first aspect.

[0044] Fourthly, a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the method for calculating combined P-wave and S-wave formation pressure as described in any one of the first aspects.

[0045] Beneficial effects: By acquiring well-logged seismic data and well-logged density data of P-waves and S-waves, and combining the two, a formation pressure calculation formula related to well-logged seismic P-wave layer velocity, S-wave layer velocity and density data is established, achieving the effect of accurate formation pressure calculation, and providing an effective means to solve the problem of accurate formation pressure calculation. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a flowchart of the calculation method proposed in one embodiment of this application;

[0048] Figure 2 This is the basic data for the calculation method proposed in one embodiment of this application;

[0049] Figure 3 This is the result data of the geostress ratio function calculation method proposed in an embodiment of this application;

[0050] Figure 4 This is a schematic diagram of the structure of a computing device proposed in an embodiment of this application. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0052] Example 1

[0053] Reference Figure 1 The flowchart illustrates a method for calculating combined P-wave and S-wave formation pressure according to an embodiment of the present invention, including the following steps:

[0054] S101: Acquire P-wave and S-wave seismic data from the well, and preprocess the P-wave and S-wave seismic data from the well.

[0055] When acquiring P-wave and S-wave seismic data in wells, surface P-wave and S-wave sources are set up near the wellhead to generate seismic data, which are then received by a three-component geophone in the well. The first result is three-component seismic data, which needs to be processed in a series of steps to obtain waveform data about the measured strata, i.e., preprocessed well seismic data.

[0056] If there is no transverse wave source during the acquisition process, a longitudinal wave source can be used to excite the waveform and convert it into a transverse wave as a substitute, but this will have some impact.

[0057] S102, based on the preprocessed well seismic data, the measured strata are divided into layers, and the P-wave velocity and S-wave velocity of each measured stratum are calculated;

[0058] The geological strata were divided into layers, and each layer was numbered to facilitate subsequent calculations. During the layering process, the strata were divided according to their depth. For example, if the depth of the strata was 1000m, it was divided into layers with a depth of 20m, and if the depth of the strata was 5000m, it was divided into layers with a depth of 50m. The layering was carried out with the goal of reducing the difficulty of calculation while obtaining accurate data.

[0059] S103, acquire well logging density data, process the well logging density data, and obtain density data for each measured formation;

[0060] Well logging density data can be obtained through conventional techniques, such as sonic transit time method, array method, equivalent depth method and Eaton method; after obtaining the well logging density data, the density data of each measured formation is calculated according to the stratification results in step S102.

[0061] S104, Based on the P-wave velocity, S-wave velocity and density data of each measured stratum, determine the geostress of the stratum to be measured in each measured stratum;

[0062] When determining the geostress of each measured stratum, the P-wave and S-wave velocities obtained from well seismic data and the density data obtained from well logging density data were combined. By combining the two types of data and establishing geostress calculation formulas related to P-wave and S-wave velocities and well logging density data, the measured geostress is more accurate, providing a more precise data basis for calculating the pressure of the formation to be measured.

[0063] S105, Based on the average density of the overlying strata of the measured stratum, determine the pressure of the overlying strata at the stratum to be measured;

[0064] The average density of the overlying rock strata is the difference between the weight and volume of the overlying rock strata, obtained through geophysical exploration methods.

[0065] S106, Based on the overlying strata pressure and the geostress at the stratum to be measured, determine the formation pressure of the stratum to be measured.

[0066] The calculation method provided in this embodiment acquires wellbore seismic data and well logging density data of P-waves and S-waves, and combines the two to establish a formation pressure calculation formula related to the P-wave layer velocity, S-wave layer velocity and density data of wellbore seismic data. This achieves the effect of accurately calculating formation pressure and provides an effective means to solve the problem of accurate formation pressure calculation.

[0067] Example 2

[0068] Reference Figure 1 The diagram illustrates a flowchart of a method for calculating combined P-wave and S-wave formation pressure according to an embodiment of the present invention. This calculation method specifically includes the following steps:

[0069] Acquire P-wave and S-wave seismic data from wells, and preprocess the P-wave and S-wave seismic data from wells.

[0070] The acquisition of P-wave and S-wave seismic data from wells includes:

[0071] An excitation point is set at the wellhead of the observation well. The excitation point is the location of the seismic source that meets the zero-source-distance VSP acquisition conditions. In this embodiment, the observation well is a vertical well. When the observation well is a directional well, depth correction is required. The selection of the excitation point needs to take into account both the well site operating conditions and drilling safety, and meet the zero-source-distance excitation distance specified in industry standard SY / T 7450-2019.

[0072] Surface P-wave and surface S-wave sources are set up and excited at the excitation point to generate P-waves and S-waves; three-component geophones are used to receive the well seismic data of P-waves and S-waves in the observation well; the well seismic data of P-waves and S-waves are all three-component seismic data with the same recording length and time and depth sampling interval.

[0073] The data obtained is as follows Figure 2 As shown, Figure 2 The basic data of the calculation method proposed in this embodiment are shown; where the solid line represents the P-wave velocity, the long dashed line represents the S-wave velocity, the corresponding horizontal axis represents the formation depth in meters, and the vertical axis represents the formation velocity in meters per second. Figure 1 The dotted line in the middle represents the formation density, with the horizontal axis representing the formation depth in meters and the vertical axis representing the formation density in kg / m³.

[0074] Preprocessing of P-wave and S-wave well seismic data includes at least one of the following: three-component rotation processing, random noise suppression processing, amplitude compensation processing, and deconvolution processing.

[0075] Among them, the three-component rotation processing refers to the redistribution of the energy of the three-component geophones in the well according to the principle of maximum energy, so as to obtain the rotated P-wave and S-wave well seismic data, which can be completed using existing commercial software.

[0076] Random noise suppression, amplitude compensation, and deconvolution are performed as needed. The best results can be achieved by using preprocessed P-wave and S-wave well seismic data with clear P-wave and S-wave first arrivals and crisp jumps, which can meet the requirements for accurate first arrival picking.

[0077] Based on the preprocessed well seismic data, the measured strata were divided into layers, and the P-wave velocity and S-wave velocity of each measured stratum were calculated.

[0078] The calculated P-wave velocity and S-wave velocity for each measured stratum include:

[0079] Based on the preprocessed well-drilled seismic data, the first arrivals of the S-wave and P-wave are picked up at the same phase on both the P-wave and S-wave, respectively. The first arrival pick-up location is the location of the wave crest maximum; these are denoted as V0 and V1, respectively. p and V sDuring pickup, since this invention uses P-wave and S-wave sources for excitation, in accordance with the national standard GB / T 33685, the pickup positions for both P-waves and S-waves are the locations of the wave crest maxima.

[0080] Based on the first arrival of the shear wave and the first arrival of the p-wave, the p-wave velocity and shear wave velocity of each measured stratum are obtained.

[0081] Acquire well logging density data, process the well logging density data to obtain density data for each measured formation; the well logging density data processing includes at least one of the following: abnormal noise removal, data depth range adjustment, and data resampling; all of which can be implemented using existing commercial software.

[0082] Abnormal noise removal involves suppressing randomly generated noise in well logging density data through data statistics.

[0083] Data depth range adjustment involves truncating or interpolating data to align the depth range of well logging density data with that of P-wave and S-wave well seismic data.

[0084] Data resampling adjusts the sampling depth of well logging density data to match the measurement depth of P-wave and S-wave well seismic data.

[0085] Based on the P-wave velocity, S-wave velocity, and density data of each measured stratum, the in-situ stress of the stratum to be measured in each measured stratum is determined, including the following steps:

[0086] A. Using the depth sampling sequence number collected by VSP, the measured strata are divided into layers. The depth sampling sequence numbers are recorded from top to bottom as 0, 1, 2, 3...i, where i is the depth sampling sequence number of the stratum to be measured.

[0087] B. Using a pressure gauge, the ground stress at layer 0 is obtained and used as a reference point, denoted as σ0;

[0088] C, based on σ0, calculate the geostress of layer σ1 using the following formula;

[0089] Formula for the geostress ratio function:

[0090]

[0091] In the formula, x is the depth sampling number of the target stratum, x = 0, 1, 2, 3…i; σ x The geostress of the stratum with depth sampling number x is σ. x-1 The geostress of the layer above the stratum with depth sampling number x is Δ. x This is a function representing the ratio of geostress between the stratum with depth sampling number x and the stratum with depth sampling number x-1.

[0092] in,

[0093] In the formula, ρ x-1 ρ represents the formation density of the stratum with depth sampling number x-1. x The formation density of the stratum with depth sampling number x-1; The P-wave velocity of the formation with depth sampling number x-1; The shear wave velocity of the formation with depth sampling number x-1; The P-wave velocity of the formation with depth sampling number x; The shear wave velocity of the formation with depth sampling number x.

[0094] Δ x The expression for this is obtained through the formula for calculating ground stress using the elastic modulus;

[0095] The elastic modulus is used to calculate the ground stress as follows:

[0096]

[0097] In the formula, σ is the geostress; ρ corresponds to the formation density. V represents the compression per unit thickness of adjacent strata. p V represents the P-wave velocity of the corresponding stratum. s This represents the shear wave velocity of the corresponding stratum.

[0098] To measure the compression per unit thickness of multiple adjacent strata. Unchanged, we get Δ x The expression.

[0099] In this embodiment, the obtained geostress ratio function is as follows: Figure 3 As shown, Figure 3 The calculation results obtained by the geostress ratio function in this calculation method are shown; where the horizontal axis is the stratum depth in meters and the vertical axis is the geostress ratio, which is dimensionless.

[0100] D. Repeat step C until x = i, and output the geostress σ of the stratum i to be measured. i .

[0101] The pressure of the overlying strata at the stratum to be measured is determined based on the average density of the overlying strata of the measured stratum.

[0102] The pressure of the overlying strata at the stratum to be measured is determined using the following formula:

[0103]

[0104] In the formula, P Oi The pressure of the overlying strata of the target stratum i; H represents the average density of the overlying rock strata. i denoted as , where is the depth of the target stratum i; and g is the gravitational acceleration.

[0105] The formation pressure of the stratum to be measured is determined based on the pressure of the overlying strata and the in-situ stress at the stratum to be measured.

[0106] Determine using the following formula

[0107] P fi =P Oi -σ i ;

[0108] In the formula, P fi This refers to the formation pressure of the stratum to be measured.

[0109] This embodiment acquires wellbore seismic data and logging density data of P-waves and S-waves, and combines the two to establish a formation pressure calculation formula related to wellbore seismic P-wave layer velocity, S-wave layer velocity and density data, thereby achieving the effect of accurately calculating formation pressure and providing an effective means to solve the problem of accurate formation pressure calculation.

[0110] Example 3

[0111] like Figure 4 As shown, this embodiment provides a combined P-wave and S-wave formation pressure calculation device, including:

[0112] The well-drilled seismic data acquisition module 101 is used to acquire well-drilled seismic data of P-waves and S-waves, and to preprocess the well-drilled seismic data of P-waves and S-waves.

[0113] The formation velocity calculation module 102, based on the preprocessed well seismic data, divides the measured formation into layers and calculates the P-wave velocity and S-wave velocity of each measured formation layer.

[0114] The density data acquisition module 103 processes the well logging density data to obtain the density data of each measured formation.

[0115] The in-situ stress determination module 104 determines the in-situ stress of the stratum to be measured in each stratum based on the P-wave velocity, S-wave velocity and density data of each measured stratum.

[0116] The overlying stratum pressure determination module 105 determines the overlying stratum pressure at the stratum to be measured based on the average density of the overlying stratum of the measured stratum.

[0117] The formation pressure determination module 106 determines the formation pressure of the formation to be measured based on the pressure of the overlying strata and the geostress at the formation to be measured.

[0118] As an optional example of an embodiment of this application, the well seismic data acquisition module 101 includes a preprocessing unit and a well seismic data acquisition unit:

[0119] The preprocessing unit is used to perform at least one of the following: three-component rotation processing, random noise suppression processing, amplitude compensation processing, and deconvolution processing.

[0120] The well-drilled seismic data acquisition unit is used to perform the following steps:

[0121] An excitation point is set at the wellhead of the observation well, and the excitation point is the location of the seismic source that meets the zero well-source distance VSP acquisition condition;

[0122] A surface P-wave source and a surface S-wave source are set at the excitation point and excited to generate P-waves and S-waves.

[0123] A three-component geophone was used to receive P-wave and S-wave seismic data in the observation well.

[0124] As an optional example of an embodiment of this application, the formation velocity measurement and calculation module 102 includes a formation velocity calculation unit for implementing the following steps:

[0125] Based on the preprocessed well seismic data, the first arrival of the shear wave and the first arrival of the p-wave are picked up at the same phase on the p-wave and shear wave respectively. The first arrival is picked up at the position of the peak maximum.

[0126] Based on the first arrival of the shear wave and the first arrival of the longitudinal wave, the longitudinal wave velocity and the shear wave velocity of each measured stratum are obtained.

[0127] As an optional example of an embodiment of this application, the density data acquisition module 103 includes a well logging density data processing unit;

[0128] The well logging density data processing unit is used to perform at least one of the following processing on the well logging density data: abnormal noise removal, data depth range adjustment, and data resampling.

[0129] As an optional example of an embodiment of this application, the in-situ stress determination module 104 includes an in-situ stress calculation unit for implementing the following steps:

[0130] A. Using the depth sampling sequence number collected by VSP, the measured strata are divided into layers. The depth sampling sequence numbers are recorded from top to bottom as 0, 1, 2, 3...i, where i is the depth sampling sequence number of the stratum to be measured.

[0131] B. Using a pressure gauge, the ground stress at layer 0 is obtained and used as a reference point, denoted as σ0;

[0132] C, based on σ0, calculate the geostress of layer σ1 using the following formula;

[0133]

[0134] In the formula, x is the depth sampling number of the target stratum, x = 0, 1, 2, 3…i; σ x The geostress of the stratum with depth sampling number x is σ. x-1 The geostress of the layer above the stratum with depth sampling number x is Δ. x This is a function representing the ratio of geostress between the stratum with depth sampling number x and the stratum with depth sampling number x-1.

[0135] in,

[0136] In the formula, ρ x-1 ρ represents the formation density of the stratum with depth sampling number x-1. x The formation density of the stratum with depth sampling number x-1; The P-wave velocity of the formation with depth sampling number x-1; The shear wave velocity of the formation with depth sampling number x-1; The P-wave velocity of the formation with depth sampling number x; The shear wave velocity of the formation with depth sampling number x;

[0137] Repeat step C until x = i, and output the geostress σ of the stratum i to be measured. i .

[0138] As an optional example of an embodiment of this application, the overlying strata pressure determination module 105 includes an overlying strata pressure calculation unit, used to implement the following steps:

[0139] The pressure of the overlying strata at the stratum to be measured is determined by the following formula:

[0140]

[0141] In the formula, P Oi The pressure of the overlying strata of the target stratum i; H represents the average density of the overlying rock strata. i denoted as , where is the depth of the target stratum i; and g is the gravitational acceleration.

[0142] As the device embodiment is basically similar to the method embodiment, the description is relatively simple, and relevant parts can be found in the description of the method embodiment.

[0143] Example 4

[0144] This embodiment provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is executed by the processor, it implements the steps of a method for calculating combined P-wave and S-wave formation pressure as described in Embodiments 1 and 2.

[0145] Example 5

[0146] This embodiment provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the steps of the P-wave and S-wave combined formation pressure calculation method as described in Embodiments 1 and 2.

[0147] Those skilled in the art will understand that embodiments of this application can be provided as methods, apparatus, or computer program products. Therefore, embodiments of this application can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of this application can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0148] This application describes embodiments with reference to flowchart illustrations and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0149] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0150] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal equipment, causing a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0151] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0152] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0153] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for calculating formation pressure using combined P-wave and S-wave propagation, characterized in that, Includes the following steps: Acquire P-wave and S-wave seismic data from wells, and preprocess the P-wave and S-wave seismic data from wells. Based on the preprocessed well seismic data, the measured strata were divided into layers, and the P-wave velocity and S-wave velocity of each measured stratum were calculated. Acquire well logging density data, process the well logging density data, and obtain density data for each measured formation layer; Based on the P-wave velocity, S-wave velocity and density data of each measured stratum, the geostress of the stratum to be measured in each measured stratum is determined. The pressure of the overlying strata at the stratum to be measured is determined based on the average density of the overlying strata. The formation pressure of the stratum to be measured is determined based on the overlying stratum pressure and the geostress at the stratum to be measured. Determining the geostress of the stratum to be measured in each measured stratum based on the P-wave velocity, S-wave velocity, and density data of each measured stratum includes the following steps: The strata to be measured are divided into layers based on the depth sampling sequence number collected by VSP. The depth sampling sequence numbers are recorded from top to bottom as 0, 1, 2, 3...i, where i is the depth sampling sequence number of the stratum to be measured. A pressure gauge is used to obtain the geostress at layer 0, which is then used as a reference point and denoted as [reference point]. ; by Based on this, calculate using the following formula. The in-situ stress of the layer; ； In the formula, x is the depth sampling number of the target stratum, x=0,1,2,3…i; The geostress of the stratum with depth sampling number x is given. This represents the geostress of the layer above the stratum with depth sampling number x. This is a function representing the ratio of geostress between the stratum with depth sampling number x and the stratum with depth sampling number x-1. in, ; In the formula, The formation density of the stratum with depth sampling number x-1; The formation density of the stratum with depth sampling number x-1; The P-wave velocity of the formation with depth sampling number x-1; The shear wave velocity of the formation with depth sampling number x-1; The P-wave velocity of the formation with depth sampling number x; The shear wave velocity of the formation with depth sampling number x; Repeat the calculation The steps for measuring the in-situ stress of the stratum are repeated until x=i, and the stratum to be measured is output. geostress .

2. The method according to claim 1, characterized in that, The acquisition of P-wave and S-wave well seismic data includes: An excitation point is set at the wellhead of the observation well, and the excitation point is the location of the seismic source that meets the zero well-source distance VSP acquisition condition; A surface P-wave source and a surface S-wave source are set at the excitation point and excited to generate P-waves and S-waves. A three-component geophone was used to receive P-wave and S-wave seismic data in the observation well.

3. The method according to claim 2, characterized in that, The preprocessing includes at least one of the following: three-component rotation processing, random noise suppression processing, amplitude compensation processing, and deconvolution processing.

4. The method according to claim 1, characterized in that, The processing of well logging density data includes at least one of the following: abnormal noise removal, data depth range adjustment, and data resampling.

5. The method according to claim 1, characterized in that, The calculated P-wave velocity and S-wave velocity of each measured stratum include: Based on the preprocessed well seismic data, the first arrival of the shear wave and the first arrival of the p-wave are picked up at the same phase on the p-wave and shear wave respectively. The first arrival is picked up at the position of the peak maximum. Based on the first arrival of the shear wave and the first arrival of the longitudinal wave, the longitudinal wave velocity and the shear wave velocity of each measured stratum are obtained.

6. The method according to claim 1, characterized in that, Determining the pressure of the overlying strata at the stratum to be measured based on the average density of the overlying strata includes: The pressure of the overlying strata at the stratum to be measured is determined by the following formula: ； In the formula, The pressure of the overlying strata of the target stratum i; The average density of the overlying rock strata; Target strata The depth of the strata; g is the acceleration due to gravity.

7. A combined P-wave and S-wave formation pressure calculation device, characterized in that, include: The well-drilled seismic data acquisition module is used to acquire well-drilled seismic data of P-waves and S-waves, and to preprocess the well-drilled seismic data of P-waves and S-waves. The formation velocity calculation module, based on preprocessed well seismic data, divides the measured formation into layers and calculates the P-wave velocity and S-wave velocity of each layer. The density data acquisition module processes the well logging density data to obtain the density data for each measured formation. The in-situ stress determination module determines the in-situ stress of the stratum to be measured in each stratum based on the P-wave velocity, S-wave velocity and density data of each measured stratum. The overlying strata pressure determination module determines the overlying strata pressure at the stratum to be measured based on the average density of the overlying strata of the measured stratum. The formation pressure determination module determines the formation pressure of the formation to be measured based on the pressure of the overlying strata and the geostress at the formation to be measured. The in-situ stress determination module for each layer includes an in-situ stress calculation unit, used to implement the following steps: The strata to be measured are divided into layers based on the depth sampling sequence number collected by VSP. The depth sampling sequence numbers are recorded from top to bottom as 0, 1, 2, 3...i, where i is the depth sampling sequence number of the stratum to be measured. A pressure gauge is used to obtain the geostress at layer 0, which is then used as a reference point and denoted as [reference point]. ; by Based on this, calculate using the following formula. The in-situ stress of the layer; ； In the formula, x is the depth sampling number of the target stratum, x=0,1,2,3…i; The geostress of the stratum with depth sampling number x is given. This represents the geostress of the layer above the stratum with depth sampling number x. This is a function representing the ratio of geostress between the stratum with depth sampling number x and the stratum with depth sampling number x-1. in, ; In the formula, The formation density of the stratum with depth sampling number x-1; The formation density of the stratum with depth sampling number x-1; The P-wave velocity of the formation with depth sampling number x-1; The shear wave velocity of the formation with depth sampling number x-1; The P-wave velocity of the formation with depth sampling number x; The shear wave velocity of the formation with depth sampling number x; Repeat the calculation The steps for measuring the in-situ stress of the stratum are repeated until x=i, and the stratum to be measured is output. geostress .

8. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of the method for calculating combined P-wave and S-wave formation pressure as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method for calculating combined P-wave and S-wave formation pressure as described in any one of claims 1 to 6.

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