79 results about "Bulk modulus" patented technology

The invention discloses a landslide construction simulation method based on finite elements, particularly relates to the field of construction simulation, and realizes whole-process dynamic simulation through GTS-NX software. Firstly, a three-dimensional finite element model is established based on geological exploration data, a Mohr-Coulomb elastic-plastic constitutive model is adopted, and the bulk modulus and the shear modulus are calculated through the elastic modulus and the Poisson's ratio. The initial ground stress is simulated by adopting a self-weight stress field method, and the initial displacement influence is eliminated by adopting a displacement difference method. In construction process simulation, the unit passivation / activation technology is adopted to accurately reproduce the excavation and support time sequence, and cyclic calculation of excavation-stress release-support-balance is achieved. In nonlinear analysis, superposition of an elastic stress field and a plastic stress field is considered, and an unloading influence factor is introduced to correct anisotropy of a deformation modulus. A safety coefficient is calculated through a strength reduction method, a multi-working-condition evaluation system is established, a monitoring data fusion and parameter inversion mechanism is developed, and a three-level early warning system is formed.

The invention provides a petroleum drilling geomechanical characteristic estimation method based on deep learning, and aims to solve the problems of high measurement cost and poor real-time performance of shear wave velocity Vs in traditional geomechanical analysis by fusing logging while drilling LWD data and real-time drilling engineering parameters. According to the method, a Transformer model is adopted to carry out depth correction on logging-while-drilling data, depth offset of a drill bit and a logging sensor is eliminated, and real-time drilling parameters such as torque T, bit pressure WOB and drilling speed ROP are combined and input into a multi-layer perceptron MLP network to predict the shear wave speed Vs. And further calculating key geomechanical parameters based on the predicted shear wave velocity Vs. In practical application, the method improves the shear wave velocity prediction accuracy to 97.2%, the mean absolute error MAE of the shear modulus is reduced from 0.186 to 0.059, and the bulk modulus is reduced from 0.189 to 0.040. The method can be used for outputting stratum elastic parameters, optimizing bit pressure, pre-warning well wall instability and adjusting a well track, well drilling safety and efficiency are improved, and meanwhile dependence on an expensive well logging technology is reduced.

The invention relates to the technical field of oil and gas geophysical exploration, and particularly discloses a tight sandstone gas reservoir fluid mobility gradient attribute prediction method and system.The method comprises the steps that a reflection coefficient expression containing a fluid mobility item is constructed, and a formula for calculating fluid mobility through frequency dispersion attributes is deduced; constructing a fluid mobility gradient attribute related to the frequency and the incident angle of the seismic wave; the method comprises the following steps: establishing a double-pore rock physical model, generating a synthetic seismic record, applying frequency variation AVO inversion to the synthetic seismic record, and extracting a bulk modulus dispersion attribute and a shear modulus dispersion attribute; and calculating the fluid fluidity changing along with the frequency and the incident angle, and calculating the gradient attribute of the fluid fluidity based on a gradient attribute calculation formula and the fluid fluidity. According to the method, seismic wave frequency dispersion and attenuation response caused by permeability and gas saturation are fully utilized, the seismic gradient attribute of the fluid fluidity and the calculation method are constructed, and high-precision prediction of the fluid fluidity by applying seismic signal elasticity and frequency dispersion rock physical information is realized.

The invention discloses a nondestructive testing method for the compressive strength of lightweight aggregate concrete based on an ultrasonic opposite testing method, and belongs to the field of engineering material testing, the method comprises the following steps: S1, detecting the ultrasonic transverse wave velocity and longitudinal wave velocity of each lightweight aggregate concrete reference piece; s2, calculating the equivalent bulk modulus of each lightweight aggregate concrete reference piece; s3, establishing a corrected KT model; s4, establishing a mapping relation equation set of the lightweight aggregate concrete reference piece and the corrected KT model, and optimizing and adjusting the corrected KT model; s5, the ultrasonic transverse wave velocity, the ultrasonic longitudinal wave velocity and the equivalent bulk modulus of the lightweight aggregate concrete test piece are obtained, and the volume fraction of the lightweight aggregate concrete test piece is calculated; and S6, calculating the compressive strength of the lightweight aggregate concrete test piece according to the volume fraction of the lightweight aggregate concrete test piece and the mapping relation between the mixing amount parameter and the compressive strength. The technical problem that the nondestructive testing error of the compressive strength of the lightweight aggregate concrete is relatively high is solved.

This invention discloses a quantitative evaluation method for the homogeneity of lightweight aggregate concrete based on rapid ultrasonic testing, belonging to the field of engineering materials testing technology. The method includes: S1, obtaining the shear wave velocity and longitudinal wave velocity at multiple test points of a series of lightweight aggregate concrete reference specimens; S2, calculating the shear modulus and bulk modulus at each test point of each reference specimen; S3, calculating the elastic modulus at each test point of each reference specimen; S4, constructing a relationship between the lightweight aggregate volume content, shear wave velocity, and longitudinal wave velocity based on the elastic modulus obtained in step S3; S5, obtaining the shear wave velocity and longitudinal wave velocity at each test point of the specimen to be tested, and calculating the lightweight aggregate volume content at each test point of the specimen to be tested based on the relationship; S6, evaluating the homogeneity of the specimen to be tested based on the lightweight aggregate volume content calculated in step S5. This invention solves the technical problem of insufficient accuracy in ultrasonic testing results for the homogeneity of lightweight aggregate concrete.

A method including obtaining measurements of one or more first parameters of a packer during an actuation of the packer in a borehole, obtaining measurements of one or more second parameters related to a geometrical change in the borehole caused by the actuation of the packer, and analyzing a plurality of first and second parameters, a plurality of derivatives of the first and second parameters, or a combination thereof to estimate at least a static bulk modulus (K) of a geological formation surrounding the borehole.

The present application relates to oil and gas geophysical exploration technology field, specifically disclose a kind of tight sandstone gas reservoir fluid mobility gradient attribute prediction method and system, the method includes constructing fluid mobility term's reflection coefficient expression, and deduce the formula for calculating fluid mobility using dispersion attribute, construct and frequency and seismic wave incidence angle related fluid mobility gradient attribute;Establish double-pore petrophysical model, generate synthetic seismogram, apply frequency-variable AVO inversion to the synthetic seismogram, extract bulk modulus dispersion attribute and shear modulus dispersion attribute;Fluid mobility changing with frequency and incidence angle is calculated, based on gradient attribute calculation formula and fluid mobility, fluid mobility gradient attribute is calculated.The present application makes full use of the response of the seismic wave dispersion and attenuation caused by permeability and gas saturation, constructs the seismic gradient attribute and calculation method of fluid mobility, realizes the high-precision prediction of fluid mobility by applying the elastic and dispersion petrophysical information of seismic signal.

The application provides a method for determining the longitudinal wave velocity after fluid replacement in an anisotropic medium and related equipment. The method comprises the following steps: determining an average bulk modulus based on a matrix bulk modulus; determining a first bulk modulus when the medium contains fluid based on first property data; determining a second bulk modulus when the medium does not contain fluid based on the first property data, the matrix bulk modulus, the average bulk modulus and the first bulk modulus; determining a second vertical stiffness coefficient when the medium does not contain fluid based on the first property data, the average bulk modulus, the first bulk modulus and the second bulk modulus; obtaining second property data of each predetermined replacement fluid; and determining the longitudinal wave velocity after the fluid in the medium is replaced by the predetermined replacement fluid based on the first property data, the average bulk modulus, the second bulk modulus, the second vertical stiffness coefficient and the second property data. The technical problem that the longitudinal wave velocity determined after fluid replacement in an anisotropic medium is not accurate in the prior art is solved.

The present application belongs to the field of material testing, and particularly relates to a viscoelastic material bulk modulus measuring device and method based on an electric measuring method, wherein the measuring device comprises a pressure tank and a viscoelastic material testing support; the viscoelastic material testing support comprises a fixing frame and a plurality of sets of deformation testing clamps; the deformation testing clamp comprises a fixed elastic sheet, a testing elastic sheet and a clamp block, the fixed elastic sheet is provided with a hollow slot in the middle, the testing elastic sheet is arranged through the hollow slot, and the fixed elastic sheet and the testing elastic sheet are perpendicular to each other, a strain gauge is pasted on the testing elastic sheet, adjacent one end of the fixed elastic sheet and the testing elastic sheet is fixedly arranged on the fixing frame, and adjacent the other end is fixedly arranged on the clamp block, and the clamp block is provided with an abutting rod perpendicular to the arrangement direction of the testing elastic sheet. The present application realizes direct and high signal-to-noise ratio measurement of the bulk strain of the viscoelastic material under a hydrostatic pressure environment by precisely isolating non-measurement direction interference through the double elastic sheet structure of the fixed elastic sheet and the testing elastic sheet of the deformation testing clamp.

The present application relates to the geological exploration technical field, more particularly, to a deep water super shallow layer natural gas reservoir rock physics shear wave velocity prediction method, comprising: calculating equivalent bulk modulus, shear modulus and density of a plurality of mineral mixed matrix according to shale content; then calculating skeleton bulk modulus and shear modulus; then calculating saturated rock bulk modulus and shear modulus through a model, and calculating saturated rock density through rock matrix density; distributing longitudinal and transverse velocities of suspended state and bearing state, and calculating equivalent longitudinal and transverse wave velocities; using equivalent longitudinal wave velocity to construct an inversion objective function with longitudinal wave velocity as a known condition; comparing actual longitudinal wave velocity with calculated longitudinal wave velocity; realizing nonlinear inversion of transverse wave velocity according to an algorithm, and obtaining transverse wave velocity of a to-be-inverted work area. The present application simultaneously considers rock physics models of particle suspended state and bearing state, and realizes transverse wave velocity prediction and deep water super shallow layer natural gas reservoir transverse wave velocity direct inversion.

The invention provides a seismic wave frequency dispersion and attenuation prediction method considering a cross-scale attenuation mechanism, and the method comprises the steps: calculating a longitudinal wave speed according to the physical parameters of a basic rock, and carrying out the reverse deduction of a first dry rock volume modulus through the longitudinal wave speed; directly calculating to obtain a second dry rock bulk modulus according to the physical parameters of the basic rock; establishing a dry rock volume modulus model of a cross-scale effect, and fusing the obtained first dry rock volume modulus and the second dry rock volume modulus in a weighted summation mode to obtain a fused dry rock volume modulus; and substituting the bulk modulus of the dry rock into a Biot equation, obtaining a relationship between frequency and wave number according to a plane wave analysis principle, and calculating longitudinal wave velocity dispersion and attenuation according to a definition formula. According to the seismic wave dispersion and attenuation prediction method considering the cross-scale attenuation mechanism, the problem of more complex multi-fluid and multi-pore type seismic wave dispersion and attenuation prediction is solved.

The invention provides a modeling method and a saturation prediction method of a rock physical model containing non-uniformly distributed hydrate sediments. Comprising the steps of obtaining model parameters, calculating the porosity of a mineral skeleton based on the model parameters, calculating the bulk modulus and the shear modulus of a dry hydrate skeleton, calculating the bulk modulus and the shear modulus of a dry mineral skeleton, and calculating the bulk modulus and the shear modulus of a dry composite skeleton composed of the dry mineral skeleton and the dry hydrate skeleton. And calculating the rock bulk modulus and shear modulus when the fluid is saturated, calculating the rock density value when the fluid is saturated, and calculating the stratum longitudinal wave velocity and the stratum transverse wave velocity. According to the method, on the basis of the forming mechanism and distribution characteristics of the non-uniformly distributed hydrates, the non-uniformity of the hydrates and mineral particles is considered in the modeling process, the hydrates and the mineral particles are regarded as two independent rock frameworks, and the isotropic rock physical model suitable for the non-uniformly distributed hydrates is constructed.

The invention discloses a rock physical model construction method, device and equipment, a medium and a product. The method comprises the following steps: determining a compaction factor according to porosity data and stratum thickness data; determining the elasticity modulus of the dry rock skeleton according to the mineral component content and the compaction factor; determining a fluid bulk modulus and a fluid density according to the water saturation data and the gas saturation data; determining a saturated rock elastic modulus according to the dry rock skeleton elastic modulus and the fluid volume modulus; determining the saturated rock density according to the fluid density and the rock matrix equivalent density, and further determining the longitudinal wave velocity and the transverse wave velocity of the saturated rock; and determining a rock physical model according to the longitudinal wave velocity and the transverse wave velocity. According to the technical scheme, the problem of poor reliability of rock physical modeling is solved, the compaction factor is introduced in the rock matrix elastic modulus determination process, the rock matrix elastic modulus considering the mechanical compaction effect is calculated, and the accuracy and effectiveness of the rock physical model can be improved.

A method including obtaining measurements of one or more first parameters of a packer during an actuation of the packer in a borehole, obtaining measurements of one or more second parameters related to a geometrical change in the borehole caused by the actuation of the packer, and analyzing a plurality of first and second parameters, a plurality of derivatives of the first and second parameters, or a combination thereof to estimate at least a static bulk modulus (K) of a geological formation surrounding the borehole.

The invention relates to the technical field of oil and gas exploration, and discloses a hole structure parameter inversion method and device, electronic equipment and a medium. The method comprises the following steps: acquiring key rock physical parameters; processing logging data of the typical well, and calculating a hole structure parameter curve of the typical well; mathematical optimization is carried out, and coefficients of hole structure parameter constraint conditions are determined; pre-stack elastic parameter inversion is used to acquire a longitudinal wave impedance data body and a transverse wave impedance data body of the work area to be inverted; based on hole structure parameter constraint conditions, establishing a nonlinear mapping relation of longitudinal wave impedance and transverse wave impedance about the porosity, and solving a porosity inversion result by using a golden section algorithm; and calculating inversion results of the volume modulus hole structure parameters and the shear modulus hole structure parameters. According to the technical scheme, density is not used, inversion of hole structure parameters is achieved only through longitudinal wave impedance and transverse wave impedance, and input data are more stable; the use conditions of hole structure parameter inversion are broadened, and the stability and precision of hole structure parameter inversion are improved.

The invention relates to the technical field of shear wave prediction methods, in particular to a shear wave forward modeling method based on VSP data participating in rock physical modeling, which comprises the following steps: establishing a rock skeleton model; establishing a dry rock elastic parameter model according to a differential equivalent medium theory; establishing a fluid attribute model; establishing a saturated fluid rock model, and calculating the effective volume modulus and the effective shear modulus of the saturated rock by using the saturated fluid rock model; and performing forward modeling to calculate the bulk modulus and the shear modulus. According to the method, VSP data participates in rock physical modeling to carry out transverse wave forward modeling matching technology, physical characteristics of underground rocks are simulated more accurately, so that a high-precision transverse wave logging curve is obtained, reference and technical guarantee are provided for other regions encountering similar problems, and follow-up pre-stack inversion, reservoir prediction and other work are promoted to be carried out; and meanwhile, during regional research, the input cost of transverse wave logging can be reduced, the exploration efficiency is effectively improved, and the exploration cost is reduced.

This invention belongs to the field of advanced metallic materials manufacturing, and relates to the design and preparation method of a high-plasticity Mg-Sn-Al magnesium alloy. First, a candidate system of Mg-xSn-yAl alloys is established. First-principles methods based on density functional theory are used to perform VCA modeling on each candidate composition and calculate elastic constants. Combined with the Voigt-Reuss-Hill model, parameters such as bulk modulus B, shear modulus G, Poisson's ratio, Pugh ratio, and Cauchy pressure are obtained. Using a Poisson's ratio greater than 0.36, a Pugh ratio greater than 3.4, and a Cauchy pressure greater than 18 GPa as screening criteria, the composition range of the high-plasticity alloy is determined to be Mg-(1-3.2)Sn-(0.7-0.8)Al (wt.%). Subsequently, alloy plates are prepared through melting and casting, hot extrusion, staged rolling, intermediate annealing, and pulsed current post-treatment, and tensile property testing and microstructure characterization are performed. The results show that the selected alloys have superior plasticity, with the Mg-3.2Sn-0.79Al alloy achieving an elongation of 15.6%. This invention enables rapid screening and preparation of high-ductility magnesium alloys, which can reduce trial-and-error costs and improve alloy design efficiency.

The application belongs to the field of rock physics and geophysical exploration, and relates to a simulation method for wettability affecting dispersion and attenuation of partially saturated sandstone, which comprises the following steps: S1. establishing a relationship between capillary pressure and water saturation for wettability correction; S2. calculating equivalent pore throat radius and effective permeability according to the relationship between capillary pressure and water saturation; S3. calculating characteristic frequency and complex bulk modulus under different wettability conditions based on a partially saturated patchy medium model; S4. simulating and comparing the characteristics of longitudinal wave velocity and attenuation under different wettability and water saturation conditions, analyzing the modulation law of frequency-dependent acoustic response caused by wettability change, and realizing quantitative characterization of the wettability effect. The step-by-step modeling method proposed in the application, combined with the wettability correction parameter represented by the contact angle, can systematically calculate the continuous coupling process from capillary pressure to equivalent pore throat structure and equivalent permeability to acoustic response, and realize quantitative analysis of the wettability change on the dispersion and attenuation law.

The invention relates to the technical field of petroleum and natural gas hydrate exploration, and discloses a method and device for identifying coexistence and occurrence types of hydrate and free gas and a medium. The method comprises the following steps: establishing a temperature-depth relational expression of stratums below the seabed; determining the depths of the bottom boundaries of the stable zones of the type I and type II hydrates; calculating a bulk modulus ksat, a shear modulus Gsat, a longitudinal wave velocity Vp, a transverse wave velocity Vs and a saturated water formation resistivity R0; comparing logging data; determining a hydrate-containing layer; determining a hydrate and free gas coexistence layer; and determining a pore filling type hydrate and free gas coexistence layer and a fracture filling type hydrate and free gas coexistence layer. According to the technical scheme, on the basis of intersection analysis of the porosity and the resistivity difference and conjoint analysis of various logging data, the hydrate and free gas coexisting stratum and the occurrence form are rapidly and effectively recognized, and the optimal target and the reservoir characteristic difference can be rapidly determined on a hydrate drilling site.

The present application discloses a pseudo-acoustic wave curve reconstruction method, device and storage medium. The method includes: calculating localized rock physical modeling parameters based on the rock physical modeling parameters of the area to be measured; substituting the localized rock physical modeling parameters into the rock physical model to obtain the bulk modulus and shear modulus of the first rock; obtaining a lithologic sensitivity curve based on the rock physical modeling parameters of the area to be measured and the bulk modulus and shear modulus of the first rock; performing low-frequency filtering on the lithologic sensitivity curve to obtain medium- and high-frequency information; performing medium- and high-frequency filtering on the original acoustic wave curve to obtain low-frequency information; fusing the medium- and high-frequency information with the low-frequency information to obtain a pseudo-acoustic wave curve. This method constructs a lithologic sensitivity curve and reconstructs a pseudo-acoustic wave curve by fusing the constructed lithologic sensitivity curve with the original acoustic wave curve, which can highlight the difference between the reservoir and the surrounding rock and facilitate the identification of lithology.

The application discloses a method and system for overpressure formation rock physics modeling considering multiple pore media, and the method comprises the following steps: constructing a rock skeleton; adding a bound water pore to the rock skeleton; adding a bound water modulus to the rock skeleton containing the bound water pore; calculating a flexible pore ratio and a flexible porosity, and then adding a flexible pore to the rock skeleton containing the bound water modulus; adding a rigid pore to the rock skeleton containing the flexible pore; adding movable fluid to the double-pore rock skeleton; determining the volume modulus and shear modulus of each type of mineral in a saturated fluid equivalent model; and optimizing and adjusting the length-width ratio of the bound water pore and the length-width ratio of the rigid pore based on the volume modulus and shear modulus of each type of mineral in the saturated fluid equivalent model. The method adds the bound water pore and modulus to the rock skeleton on the basis of predicting formation pore pressure, adds fluid under consideration of different pore conditions, and thus improves the accuracy and reliability of the prediction result of the model velocity.

The embodiment of the application relates to the technical field of seismic exploration, and discloses a brittle prediction method, device, equipment and medium for a rock reservoir, the prediction method comprising the following steps: based on well logging data of a target rock reservoir, a target layer section of the target rock reservoir is constructed according to rock components and rock physical characteristic parameters, so as to construct a rock physical model for representing the relationship between the volume modulus, shear modulus, rock density and the content of main brittle minerals of the rock; a model of a brittle indicator factor is constructed according to the rock physical model and the change of the content of the main brittle minerals, the brittle indicator factor being used for representing the relative brittle degree of the rock mass; and the brittle indicator factor is converted into actual brittleness for representing the actual brittle degree of the rock mass. The brittle prediction method disclosed by the application fully utilizes the rock physical characteristic analysis of the target rock reservoir to analyze the influence of the brittle minerals on the brittle prediction, and effectively improves the rationality and accuracy of the rock brittle prediction.

This application relates to a method for calculating the internal pressure and output force of a hydraulic muscle using multi-factor coupling, comprising the following steps: obtaining the initial geometric parameters and rubber material parameters of the hydraulic muscle; constructing a multi-factor coupled output model based on the initial geometric parameters and rubber material parameters; and obtaining the input parameters of the hydraulic muscle, including the internal pressure data of the hydraulic muscle at the previous moment, the hydraulic oil input flow rate data at the current moment, the length data at the current moment, and the equivalent bulk modulus of elasticity data. This method, by constructing a multi-factor coupled output model, achieves high-precision calculation of the internal pressure and output force of the hydraulic muscle, significantly improving the physical realism of the simulation results. Furthermore, the initial geometric parameters and rubber material parameters required for model construction can be obtained by consulting product manuals or through simple measurements, solving the core pain points of existing data-driven methods, such as poor versatility and high calibration costs.

This invention discloses a method, apparatus, electronic device, and program product for predicting transverse and longitudinal wave velocities in rocks. The method includes: obtaining the porosity, density, and volume contents of quartz, clay, carbonate rocks, and pyrite in a marine-continental transitional shale rock; determining the equivalent matrix elastic modulus based on the porosity and the volume contents of quartz, clay, carbonate rocks, and pyrite; determining the volume modulus and shear modulus of the organic matter framework based on the volume modulus and shear modulus of the main phase material and the volume contents, volume modulus, and shear modulus of inclusions; obtaining the volume modulus and shear modulus of the shale matrix minerals based on the equivalent matrix elastic modulus, the volume modulus and shear modulus of the organic matter framework; and determining the volume modulus and shear modulus of the shale under saturated fluid conditions by mixing fluids, shale matrix minerals, and hard pores and fractures. This method can accurately predict transverse and longitudinal wave velocities.

The present application relates to a kind of double-scale full-band petrophysical modeling method, which is according to the inversion of target area rock P-wave and S-wave velocity, obtains the distribution of rock soft porosity and soft pore aspect ratio under different pressure;According to the distribution of rock soft porosity and soft pore aspect ratio, the frequency-dependent rock wet skeleton considering all aspect ratio soft pore jet flow effect is calculated using jet flow model;The frequency-dependent rock wet skeleton is brought into the frequency-dependent bulk modulus model of patch-saturated rock, and the petrophysical model considering micro and macro scale wave-induced flow effect is obtained.The present application comprehensively considers the influence of micro jet flow effect and mesoscale patch saturation, simulates the dispersion attenuation phenomenon caused by complex pore structure and complex fluid distribution of actual rock, and is more in line with the pore structure and fluid distribution in actual reservoir rock.

The invention provides a method, equipment and medium for estimating the acoustic velocity and density of multi-component mixed gas, and the method comprises the steps: introducing a temperature dependence function according to a Wilke gas mixing rule, and obtaining an absorption coefficient and a rejection coefficient of each component gas; defining the temperature dependence function to obtain an absorption coefficient and a rejection coefficient of the mixed gas; based on a temperature dependence function, improving a Peng-Robinson state equation to obtain the density and bulk modulus of the multi-component mixed gas, and then calculating the acoustic velocity of the multi-component mixed gas; and according to a Lohrenz-Bray-Clark model, the viscosity of the multi-component mixed gas is calculated. According to the method, a Peng-Robinson state equation is improved by introducing a temperature dependence function and a Wilke gas mixing rule so as to calculate the density and acoustic velocity of the multi-component mixed gas under different temperature-pressure conditions, and the viscosity of the multi-component mixed gas is obtained by combining and utilizing a Lohrenz-Bray-Clark model. And the accuracy of estimating the density, the acoustic velocity and the viscosity of the multi-component mixed gas is improved.

The application provides a fluid bulk modulus parameter extraction method, a fluid identification method, equipment and a medium, wherein the parameter extraction method comprises the following steps: dividing a seismic gather into at least three angle intervals, selecting a typical angle for each interval, and obtaining a corresponding partial stack for each interval; obtaining an elastic impedance curve and a curve of K f , f m and p for each typical angle from well logging data; performing elastic impedance inversion on the elastic impedance curve and the partial stack to obtain elastic impedance data of the typical angle; extracting wellside elastic impedance data from the corresponding elastic impedance data body by well logging; constructing a calculation relationship by using the curve of K f , f m and p and the elastic impedance curve of each typical angle, and bringing the curve of K f , f m and p and the wellside elastic impedance data into the calculation relationship to extract fluid bulk modulus. The technical scheme of the application can improve the resolution of the elastic impedance data body, reduce fluid identification artifacts, and improve the drilling rate of fluid inversion.

The present invention discloses a method for controlling the motion of a hydraulic manipulator based on low-pressure bulk modulus compensation. The method comprises: establishing a dynamic linearization model of a multi-degree-of-freedom hydraulic manipulator including an effective bulk modulus; designing an adaptive robust controller using a backstepping method; inputting the desired joint angle into the adaptive robust controller; and simultaneously performing online adaptive parameter updates. The adaptive robust controller processes and outputs a virtual control flow of the multi-degree-of-freedom hydraulic manipulator; static mapping is performed to obtain a valve port control voltage, thereby controlling the hydraulic valve; and the multi-degree-of-freedom hydraulic manipulator outputs the actual control flow, actual joint control torque, and actual joint angle to the adaptive robust controller in real time, thereby achieving closed-loop motion control of the multi-degree-of-freedom hydraulic manipulator. The method of the present invention can achieve high-precision motion tracking performance for the hydraulic manipulator while maintaining a stable low pressure.

The present application belongs to the technical field of rock physics, and is especially a longitudinal wave velocity calculation method under a gas-water system. The method comprises the following steps: S1: obtaining longitudinal and transverse wave velocities of a sample under normal pressure and under a limit high pressure through experiments; S2: calculating a skeleton bulk modulus and a clay water relaxation time according to a sample XRD mineral analysis result; S3: converting the wave velocities into moduli; S4: calculating saturated volcanic lava longitudinal wave velocities considering frequency dispersion according to a Gurevich formula; S5: measuring a nuclear magnetic T2 spectrum of the sample under a saturated state; S6: calculating bulk moduli under different saturation degrees; and S7: converting to obtain longitudinal wave velocities under different saturation degrees. The present application explains the reason why the volcanic lava saturation degree-longitudinal wave velocity rule presents a "convex" shape from a mechanism, and effectively calculates volcanic lava longitudinal wave velocities under different saturation degrees.

The application discloses a three-parameter-based dry rock volume modulus calculation method, device, equipment and medium. The method comprises the following steps: determining a first physical characteristic parameter of a target dry rock; and determining a first dry rock volume modulus by using a relational model according to the first physical characteristic parameter of the target dry rock. The method can solve the problem that the adaptability of the existing dry rock volume modulus calculation method is poor, so that the seismic wave velocity calculation formed on the basis is not accurate enough, and the calculation precision of the dry rock volume modulus is improved.