Baker Hughes Corporation

Baker Hughes, a Ge Compnay, LLC

Min Lou

Xiaomin Zhao

James C Jackson

Francis D Doherty

Jitendra S Gulati

A method for performing a formation-related operation based on corrected vertical seismic profile (VSP) data of an earth formation includes performing a VSP survey and applying a normal moveout (NMO) correction equation to the survey data that is a function of source offset to wellhead. The method also includes solving the NMO correction equation using a simulated annealing algorithm having an object function that is a coherence coefficient of semblance analysis of an NMO corrected reflection event within a time window to provide NMO corrected data. The method further includes performing the formation-related operation at at least one of a location, a depth and a depth interval based on the VSP NMO corrected data.

Anisotropic NMO correction and its application to attenuate noises in VSP data

First-order free-surface multiples recorded in VSP data or reverse VSP data are processed using VSP/CDP method to produce an image of the subsurface. This image produces a larger coverage than that obtained in 3-C 3-D processing of reflection data acquired in the VSP.

Extending the coverage of VSP/CDP imaging by using first-order downgoing multiples

A walkaway VSP survey is carried out with receivers located in a borehole under a salt overhang. Redatuming of the multicomponent data to virtual sources in the borehole followed by vector Kirchhoff migration using a simple velocity model provides an accurate image of the salt face.

Vector migration of virtual source VSP data

A walkaway VSP survey is carried out with receivers located in a borehole near the base salt. Reflection tomographic inversion of data from the walkaway VSP is used to derive a velocity model for the subsurface and may be used for imaging of sub-salt reflections.

Sub-salt reflection tomography and imaging by walkaway VSP survey

1order free-surface multiples recorded in VSP data or reverse VSP data are processed using a 3-C 3-D vector migration method to produce an image of the subsurface. This image produces a larger coverage than that obtained in 3-C 3-D processing of reflection data acquired in the VSP.

Vector migration of 1st order free-surface related downgoing multiples from VSP data

A technique for calculating traveltime of a seismic wave in three dimensional tilted transversely isotropic (3D TI) media includes determining a wave vector, defining a unit vector, calculating an angle of the wave vector from an axis and performing a slowness determination, wherein a unit vector for a symmetry axis is defined as: (cos &#x3c6; sin &#x3b8;, sin &#x3c6; sin &#x3b8;, cos &#x3b8;); where &#x3c6; represents the azimuth of the symmetry axis measured from the x direction; and, &#x3b8; represents the dip angle of the symmetry axis measured from the z direction. The technique may be practiced as a computer implemented set of instructions, and may be incorporated into measurement equipment.

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Houston, TX, United States of America

Min Lou