43 results about "Geophysical inversion" patented technology

Domain characterization generated by Voronoi tessellation, which is very close to realistic geology and computation of gravity response of such domain, has a three dimensional fractal basin structure, and is favorable for oil exploration. Interfaces or tessellating domains are represented by a set of parameters, which are referred as Voronoi centers. These parameters can be perturbed by any amount without getting into representational problems. To accomplish such representation Voronoi tessellation is used, which in two dimensional space involves enclosing every Voronoi center by a Voronoi polygon such that the common edge of adjacent polygons is a perpendicular bisector to the line joining the Voronoi centers on both the sides of that edge. Instead of using conventional Euclidian distances, the notion of Voronoi tessellation is generalized by using Lp distances, where p can hold any real value so that Voronoi domains are not necessarily polygonal. A desired fractal subsurface is generated using this approach that is quite close to the natural settings. Next, the gravity response due to this fractal subsurface structure is computed. A significant advantage is provided especially in geophysical inversion where initial model parameters are updated in each iteration, which can be done more easily and efficiently by Voronoi tessellation merely by changing Voronoi centers.

Method for reducing the time needed to perform geophysical inversion by using simultaneous encoded sources in the simulation steps of the inversion process. The geophysical survey data are prepared by encoding (3) a group of source gathers (1), using for each gather a different encoding signature selected from a set (2) of non-equivalent encoding signatures. Then, the encoded gathers are summed (4) by summing all traces corresponding to the same receiver from each gather, resulting in a simultaneous encoded gather. (Alternatively, the geophysical data are acquired from simultaneously encoded sources.) The simulation steps needed for inversion are then calculated using a particular assumed velocity (or other physical property) model (5) and simultaneously activated encoded sources using the same encoding scheme used on the measured data. The result is an updated physical properties model (6) that may be further updated (7) by additional iterations.

Method for reducing the time needed to perform geophysical inversion by using simultaneous encoded sources in the simulation steps of the inversion process. The geophysical survey data are prepared by encoding (3) a group of source gathers (1), using for each gather a different encoding signature selected from a set (2) of non-equivalent encoding signatures. Then, the encoded gathers are summed (4) by summing all traces corresponding to the same receiver from each gather, resulting in a simultaneous encoded gather. (Alternatively, the geophysical data are acquired from simultaneously encoded sources.) The simulation steps needed for inversion are then calculated using a particular assumed velocity (or other physical property) model (5) and simultaneously activated encoded sources using the same encoding scheme used on the measured data. The result is an updated physical properties model (6) that may be further updated (7) by additional iterations.

The invention discloses a geophysics inversion method based on a generic function reconstruction under a modified total variation model constraint. The method comprises the following steps: (1) constructing an inversion objective function aiming at the problem of regularized inversion of the modified total variation model constraint; (2) performing a generic function reconstruction on stable function terms of the modified total variation; (3) iteratively solving a calculation formula of a new model on the model itself according to an objective function minimization equation; and (4) setting inversion parameters, repeating the iteration to obtain a desired model result, and the result is used for inferring geological structures or positioning geological anomaly bodies. According to the geophysics inversion method based on the generic function reconstruction under the modified total variation model constraint, a generic function reconstruction method is innovatively provided, and the constraint property of the stable function term on the model is reserved, thereby greatly simplifying the numerical calculation difficulty caused by the high nonlinearity to the inversion; the inversionadopts a solution mode which is iterative to the model itself, and compared with a solution mode which is iterative to the correction amount of the model, the regularization directly applies a stablefunction constraint on the model, thereby obtaining a more reasonable model result.

The invention provides an anisotropic parameter inversion method based on a transmission equation, which belongs to the field of geophysical inversion. The method includes: (1) selecting post-stack seismic data volumes corresponding to any three different azimuth angles, calculating the reflection coefficients corresponding to the three different azimuth angles through sparse pulse inversion method; (2) calculating three different azimuth angles respectively. The transmission coefficient corresponding to the reflection coefficient of the azimuth angle (3) analyze the pre-stack azimuth gather to obtain the incident angle information, the incident angle information includes the maximum incident angle i2, the minimum incident angle i1 and the interval; (4) use the azimuth information transmission coefficient The information is calculated to obtain the anisotropy parameters Δε(V) and Δδ(V).