90 results about "Transverse isotropy" patented technology

A method for estimating seismic velocities in vertically transversely isotropic media includes generating an initial estimate of vertical interval velocity and interval normal moveout velocity with respect to depth from seismic data. An initial estimate is generated of a first anisotropy parameter with respect to depth. The first anisotropy parameter is related to the interval normal moveout velocity and the interval vertical velocity. An initial estimate is generated with respect to depth of a second anisotropy parameter. The second anisotropy parameter is related to the first anisotropy parameter and an interval anelliptic parameter. A first tomographic inversion is performed with respect to the interval normal moveout velocity and the second anisotropy parameter at a constant value of the first anisotropy parameter until travel time differentials reach minimum values. Layer depths are adjusted with the initial estimate of vertical interval velocity. Using values of the second anisotropy parameter determined in the first tomographic inversion, a second tomographic inversion is performed of interval normal moveout velocity and the first anisotropy parameter with respect to depth. The adjusted layer depths, interval normal moveout velocities and interval vertical velocities are again adjusted and interval anelliptic parameters are calculated from the second tomographic inversion.

A method for predicting mechanical properties of a transverse isotropic region of a rock formation traversed by a well bore including running a logging tool in the well bore; the mass percentages of minerals present in the rock formation surrounding the well bore are measured with the logging tool. The density of the minerals present in the rock formation surrounding the well bore is determined. The porosity of the rock formation surrounding the well bore is measured. From the porosity and the measured mass percentages and density of the minerals, all the transverse isotropic elastic coefficients of the rock formation are determined in real time.

A method for predicting mechanical properties of a transverse isotropic region of a rock formation traversed by a well bore including running a logging tool in the well bore; the mass percentages of minerals present in the rock formation surrounding the well bore are measured with the logging tool. The density of the minerals present in the rock formation surrounding the well bore is determined. The porosity of the rock formation surrounding the well bore is measured. From the porosity and the measured mass percentages and density of the minerals, all the transverse isotropic elastic coefficients of the rock formation are determined in real time.

The invention relates to an anisotropic reverse time migration method for a quasi-P wave equation in a transverse isotropy with a vertical axis of symmetry (VTI) medium. The method comprises the following steps of: (1) performing discrete differentiation on a first-order quasi-P wave equation in a two-dimensional VTI medium and a perfect matched layer (PML) absorption layer boundary equation by adopting staggered meshes to obtain high-order difference formats of forward continuation and reverse continuation of the two equations; (2) performing numeric calculation to obtain a forwards-continued wave field of a shot point and a reverse time continued wave field of a receiver point, and performing normalized correlation operation on the two wave fields to obtain a migration imaging result of each imaging point in a model; and (3) extracting common imaging point gathers from migration results to obtain a final migration profile. By the method, a problem about the migration imaging of intensive transverse speed variation and a high dip angle stratum can be solved; and the influence of anisotropy of the medium is also taken into account, and the good imaging effect of longitudinal wave data acquired from an anisotropic region can be achieved by an anisotropy-theory-based migration method.

The invention provides a manual shale physical model and a manufacturing method and application of the manual shale physical model. The manufacturing method of the manual shale physical model includes the first step of mixing adhesives and stone powder evenly, wherein the adhesives are epoxy resin adhesives, the stone powder comprises 10%-70% of quart, 10%-80% of kaoline, 4%-25% of organic carbon powder and 3%-10% of calcite, and the use amount of the adhesives is 5%-35% of the total mass of the stone powder, the second step of filling a mould with mixtures of the adhesives and the stone powder, placing and fixing the mould on a pressure gauge horizontally, adjusting the perpendicular pressure intensity to 80-300 MPa, fixedly placing the mould for more than 24 hours for preliminary solidifying, and the third step of demoulding, drying a shale sample subjected to preliminary solidifying at the temperature ranging from 30 DEG C to 50 DEGC and obtaining the manual shale physical model. The obtained manual shale physical model is compact, has specific porosity and density, has anisotropic characteristics, has transverse isotropic characteristics and can provide a reliable basis for comparison and verification of research results of actual shale reservoir strata.

Systems and methods for imaging seismic data using hybrid one-way wave-equation-migration in tilted transverse isotropic media and / or hybrid two-way reverse-time-migration in tilted transverse isotropic media.

A method is disclosed for depth migrating seismic data. The method includes pre-stack time migrating the seismic data to form a stacked, time migrated image. The stacked, time migrated image is demigrated, and post-stack depth migration is then performed on the demigrated image. In some embodiments, the pre-stack time migration and the demigration account for ray bending in vertically transversely isotropic media.

The invention relates to a transverse isotropy fiber material performance prediction method based on a micro-mechanical model. Composite basic material performance, matrix material performance and elasticity moduli in the fiber length direction serve as input parameters, the initial value of the transverse isotropy fiber material performance is acquired through inversion of the micro-mechanical theory model, and the transverse isotropy fiber material performance is acquired through calculation according to a finite element optimization method based on the micro-mechanical model. The optimization method for acquiring the transverse isotropy fiber material performance is provided, the transverse isotropy fiber material performance difficult to acquire through tests is acquired through the finite element model based on micro-mechanics, and necessary material performance parameters are provided for the micro-mechanical research of composites.

The invention relates to a transverse isotropy stratum elastic coefficient well logging calculation method and device. The method comprises the steps that coring in different directions is carried out on a rock core, and a rock core sample is obtained; the rock core sample is measured, the longitudinal wave speed and the transverse wave speed of the rock core sample are obtained, and elastic coefficients C11, C13, C33, C44 and C66 are obtained by calculation of the longitudinal wave speed and the transverse wave speed; the elastic coefficients C33, C44 and C66 are obtained through array acoustic logging data and density logging data of a coring well; a combination relational expression between the measurable logging elastic coefficients C33, C44 and C66 and the unmeasurable logging elastic coefficients C11 and C13 is built by the utilization of the elastic coefficients C11, C13, C33, C44 and C66 obtained by calculation of the longitudinal wave speed and the transverse wave speed; the elastic coefficients C33, C44 and C66 obtained through the array acoustic logging data and the density logging data of the coring well are substituted to the combination relational expression, the unmeasurable logging elastic coefficients C11 and C13 are obtained, and finally the elastic coefficients representing the transverse isotropy stratum are obtained.

The invention discloses a determination method for mechanical parameters of transverse isotropy shale reservoir rocks. The determination method comprises the following steps: carrying out an X-ray diffraction experiment to determine rock mineral constituents of a certain well depth; inverting rock porosity of the certain well depth by utilizing acoustic logging information; determining the stacking density of clay by utilizing the determined rock mineral constituents and the porosity; determining rigidity matrixes of transverse isotropy rocks of shale under a scale 0 by using a closed cycle-correction-identification method; determining the rigidity matrixes of the transverse isotropy rocks of the shale under a scale 1 and a scale 2 by utilizing a pore elastic theory; and substituting the rigidity matrixes into inversion models of Young modulus, poisson ratio and shear modulus and determining the mechanical parameters of the rocks. According to the determination method, the mechanical strength parameters of the rocks are inverted by using the X-ray diffraction experiment, so that the inversion result is accurate on the basis of establishing the experiment; field rock fragments are easy to obtain so that the determination method has the characteristics of time conservation, labor conservation and money conservation in the aspect of experiment operation.

An integrated semiconductor device for measuring a magnetic field, comprising: a Hall sensor, a first lateral isotropic sensor having a first stress sensitivity and a first temperature sensitivity, a second lateral isotropic sensor having a second stress sensitivity and a second temperature sensitivity, optional amplifying means, digitization means; and calculation means configured for calculating a stress and temperature compensated Hall value in the digital domain, based on a predefined formula which can be expressed as an n-th order polynomial in only two parameters. These parameters may be obtained directly from the sensor elements, or they may be calculated from a set of two simultaneous equations. A method of obtaining a Hall voltage signal, and compensating said signal for stress and temperature drift.

A method for survey data processing compensates for visco-acoustic effects in TTI medium in an RTM method. This method employs propagating in conjugate medium to yield correct phase, and acoustic wave propagation to yield correct amplitudes through adaptive matching filtering.

A method of TI formation evaluation is disclosed. The method comprises receiving a plurality of borehole measurements; deriving a correlation between a first TI stiffness parameter and other TI stiffness parameters where the first and other TI stiffness parameters representing mechanical behavior of the TI formation; and computing the first and other TI stiffness parameters based on the borehole measurements and the derived correlation. The method further comprises evaluating TI formation elastic properties based on the computed first and other TI stiffness parameters. The method further comprises assuming that the shear modulus parallel to TI symmetric axis can be approximated from other moduli.

A method for migrating three dimensional seismic data in tilted transversely isotropic media (“TTI”) is based on generating numerical solutions to an exact relationship for a three dimensional dispersion relationship of seismic energy traveling through TTI media. The numerical solutions use selected input values of polar angle and azimuth angle of a transverse isotropic axis of symmetry, and selected values of Thomsen anisotropic parameters to generate tables of numerical values. Based on the tables of numerical values, optimized coefficients for a finite-difference relationship are estimated along multiple splitting directions. The seismic data are then migrated using a three dimensional Fourier finite difference extrapolation algorithm.

A method is disclosed for migrating seismic data which includes determining travel time of a compressional wave from a source location to a scatter point, taking into account ray bending. Travel time of a shear wave from the scatter point to a receiver location is determined, taking into account ray bending at the interfaces between subsurface strata. The determined travel times are then used to migrate the seismic data. In one embodiment, the travel times take account of vertically transversely isotropic media with a vertical symmetry axis.

A method for estimating seismic velocities in vertically transversely isotropic media includes generating an initial estimate of vertical interval velocity and interval normal moveout velocity with respect to depth from seismic data. An initial estimate is generated of a first anisotropy parameter with respect to depth. The first anisotropy parameter is related to the interval normal moveout velocity and the interval vertical velocity. An initial estimate is generated with respect to depth of a second anisotropy parameter. The second anisotropy parameter is related to the first anisotropy parameter and an interval anelliptic parameter. A first tomographic inversion is performed with respect to the interval normal moveout velocity and the second anisotropy parameter at a constant value of the first anisotropy parameter until travel time differentials reach minimum values. Layer depths are adjusted with the initial estimate of vertical interval velocity. Using values of the second anisotropy parameter determined in the first tomographic inversion, a second tomographic inversion is performed of interval normal moveout velocity and the first anisotropy parameter with respect to depth. The adjusted layer depths, interval normal moveout velocities and interval vertical velocities are again adjusted and interval anelliptic parameters are calculated from the second tomographic inversion.

The present invention is directed towards a golf ball which comprises a core, a cover and at least one improved intermediate layer disposed between core and the cover. The intermediate layer a composite of at least two dissimilar materials that is radially oriented and transversely isotropic so that the layer provides unique performance properties when the ball is struck with different clubs.

A method for determining positions and origin times of seismic events occurring in the Earth's subsurface includes accepting as input to the method signals recorded from a plurality of seismic sensors deployed above a subsurface volume of interest. The recorded signals are a representation of seismic amplitude with respect to time. Origin time and location of each of a plurality of subsurface seismic events are determined from the recorded signals. The origin times and locations of each event are inverted to obtain Thomsen's parameters in formations in the volume of interest. Depths of each of the events are determined by individually searching the depth of each event, the inversion with each incorporated new depth including updating the Thomsen parameters and setting as a limit a minimum value of RMS error.

Systems and methods for imaging seismic data using hybrid one-way wave-equation-migration in tilted transverse isotropic media and / or hybrid two-way reverse-time-migration in tilted transverse isotropic media.

The invention provides a seismic inversion method and a device. The method comprises the following steps: determining the vertical slowness relation of plane P-wave in a reservoir to be tested based on the value of P-wave velocity in the vertical direction in the reservoir to be tested, the change of P-wave velocity with phase angle near vertical incidence, the horizontal slowness, and the difference between P-wave velocity in the transverse direction and P-wave velocity in the vertical direction; determining the vertical slowness relation of plane S-wave in the reservoir to be tested according to the value of S-wave velocity in the vertical direction in the reservoir to be tested; and building a new reflection coefficient calculation approach of a transversely isotropic medium with a vertical symmetry axis, and inverting the reservoir to be tested. In the embodiment of the invention, the two relations have high calculation accuracy, and have a relatively simple form and relatively weak nonlinearity. The simplified reflection coefficient calculation approach has high calculation accuracy under the conditions of strong anisotropy, large impedance difference and large incident angle. The accuracy of oil exploration is improved.

The invention provides an orthotropic dielectric fluid factor and fracture parameter inversion method. The method comprises the following steps: deducing a rigidity matrix of an ortho-symmetric anisotropic fracture medium by using a vertical transverse isotropic medium under a dry rock background according to fracture weakness; with utilization of hypotheses of weak anisotropy and small fracture weakness, deducing a new expression of weak anisotropy approximate rigidity of a saturated fluid rock in an orthogonal medium by combining an anisotropy Gassmann equation; acquiring a PP wave linearized reflection coefficient for fluid and fracture parameter decoupling in the orthogonally symmetrical weak anisotropic medium by combining stiffness disturbance and scattering theories; and with logging information as prior information, realizing elastic impedance pre-stack inversion changing with offset and azimuth angle by using a partial incident angle stacked by azimuth seismic data under Bayesian framework. According to the invention, Reliable results can be provided for fluid identification and fracture characterization; and technical supports are provided for seismic wave propagation research, oil and gas development and seismic disaster prevention.

A method is disclosed for depth migrating seismic data. The method includes pre-stack time migrating the seismic data to form a stacked, time migrated image. The stacked, time migrated image is demigrated, and post-stack depth migration is then performed on the demigrated image. In some embodiments, the pre-stack time migration and the demigration account for ray bending in vertically transversely isotropic media.

The invention provides an oil crack reservoir inversion method based on matrix-fluid-crack decoupling. The method comprises the steps that firstly, a Born approximation theory and a first-order disturbance hypothesis are utilized to derive a linearized PP wave reflection coefficient at a horizontal transverse isotropic medium interface of two filling saturated fluids based on matrix-fluid-crack decoupling; and secondly, geological data and logging data are used as prior information, partial incident angle superposition azimuth seismic data is utilized to realize azimuth prestack inversion, a rock background matrix elasticity modulus, a fluid volume modulus and crack weakness in a Bayesian framework are estimated according to an inversion result, and therefore fluid recognition and crack detection on a saturated fluid crack type reservoir are realized. According to the method, compared with other fluid indication factors, dual influences of rock porosity and pore fluids can be eliminated by using the effective pore fluid volume modulus as one fluid indication factor, and therefore the reservoir fluids can be recognized more effectively.

A computer implemented method including a numerical model of a region of the earth modeling the acoustic behavior of that region. The method implements an acoustic wave propagator allowing the simulation of the propagation of pure P-waves in transversal isotropic media. The propagator can be applied to applications such as seismic forward modeling, reverse time migration and other two-way wave-equation based applications.

A method is disclosed for migrating seismic data which includes determining travel time of a compressional wave from a source location to a scatter point, taking into account ray bending. Travel time of a shear wave from the scatter point to a receiver location is determined, taking into account ray bending at the interfaces between subsurface strata. The determined travel times are then used to migrate the seismic data. In one embodiment, the travel times take account of vertically transversely isotropic media with a vertical symmetry axis.

The invention discloses an automatic generating method of a three-dimensional woven composite hexahedron finite element model. The method includes the following steps that a space trajectory in the fiber bundle center weaving process is calculated, and position coordinates of the center of each fiber bundle are obtained; position coordinates of space trajectories of center points of the fiber bundles are read, in other words, the position coordinates of each tightened fiber bundle are read, and geometric creation, direction grouping and hexahedron meshing are carried out. By means of the method, the rapid finite element model establishment function of a complex geometric structure three-dimensional woven composite can be achieved only by inputting multiple simple macroparameters. In combination with the geometric structure and finite element modeling, grouping is carried out according to fiber bundle center direction vectors, material spindle direction setting of transverse isotropy materials of the fiber bundles is convenient, the change of internal zone, surface zone and corner zone fiber bundle sections is considered, and transverse isotropy finite element model establishment of the large-size three-dimensional woven composite can be achieved in reality from being manually feasible theoretically.

The invention relates to a device and a method for measuring shearing property of a transverse isotropic material. The device comprises a thin-wall tubular test piece, a fixed outer tube, a rotary inner tube, an upper positioning ring, a lower positioning ring, structure adhesive, an upper connecting disc, a lower connecting disc, a flange and a torque sensor. The transverse isotropic material is processed into the thin-wall tubular test piece, the axial direction is a direction I, a direction II and a direction III (transverse direction) are mutually perpendicular to each other in a cross section, and the mechanical properties of the material are identical. The rotary inner tube and the fixed outer tube are respectively bonded to the inner wall and the outer wall of the test piece, the outer tube is fixed, and a torsion torque is applied to the inner tube, so that the test piece only generates a shearing force in the thin-wall annular cross section. The shearing stress-strain curve of the test piece in the directions (transverse) II and III can be acquired by virtue of the torque of the outer tube, a torsion angle of the inner pipe and the outer wall surface of the inner tube, so that the shearing modulus and shearing strength of the test piece in the transverse isotropic direction can be obtained. The relative twisting of the inner wall and the outer wall of the thin-wall tube is ingeniously utilized, so that the shearing force is only generated in the transverse isotropic direction of the material, the parameter is intuitive and convenient to measure, and the test data is accurate.

The invention discloses an inversion method and system of an anisotropic rock physical model. The inversion method comprises the following steps of establishing a rock physical model with a transverseisotropic elastic characteristic; based on the Bayesian theory, obtaining the posterior probability distribution; establishing an inversion objective function based on the rock physical model and theposterior probability distribution; and obtaining an optimal solution of the fracture density parameter based on the objective function. The method has the advantages that an anisotropic rock physical modeling method is provided; the influence of anisotropic clay and directionally arranged micro cracks on shale anisotropy can be comprehensively considered, rock physical inversion is carried out on the basis of a Bayesian framework with prior information and logging parameters as constraints, the elastic parameters of clay minerals and the density of the directionally arranged cracks are obtained, and therefore the anisotropy characteristics of the clay minerals are further discussed.

The invention provides an extraction method and an extraction device for extracting the converted wave angle gather of transversely isotropic media. The method comprises the steps of based on a co-conversion point gather of pre-stack converted waves, obtaining a converted-wave stacking velocity Vc2, a vertical velocity ratio gamma 0, an equivalent speed ratio gamma eff and a converted wave anisotropic parameter Chi eff through the velocity analysis progress; at a k-th sampling point, processing each seismic trace in the co-conversion point gather to obtain an incident angle theta k at the k-th layer of the pre-stack converted waves; assigning k to be 1 to n, and conducting the above treatment for each k value so as to obtain a converted-wave incident angle of each seismic trace at each sampling point; classifying seismic traces of the same converted-wave incident angle into the same incident angle gather so as to obtain a converted wave angle gather, wherein n represents the number of total sampling points.

The invention discloses a method for detecting residual stress of a fiber-texture film, and belongs to the technical field of characteristic characterization of film materials. According to the invention, the problem of inaccurate testing of the residual stress of the fiber-texture film by adopting a traditional method is solved. Based on the transverse isotropy of the fiber-texture film, a specific solution is provided for residual stress analysis of the fiber-texture film; and through coordinate system conversion, elastic tensor of a sample under a sample coordinate system is directly calculated, so that the relationship between macroscopic residual stress and strain under the sample coordinate system can be established according to the generalized Hooke law. By adopting the theoreticalmodel of the relationship between the residual stress and the strain established by the invention, the problem that the residual stress of the fiber-texture film is not accurately tested by the traditional X-ray diffraction stress testing method can be effectively solved; and the method can be applied to detection of the residual stress of the fiber-texture film.