Exxonmobil Upstream Research Company

Nathan Downey

Partha Sarathi Routh

Jerome R Krebs

Christine E Krohn

Pavel Dimitrov

Sunwoong Lee

Anoop A Mullur

Young Ho Cha

Method for selecting an acquisition geometry for a seismic survey based on ability to resolve an a priori velocity model. Two or more candidate acquisition geometries are selected (), differing in areal coverage and cost to perform. Then compute a synthetic seismic dataset for each geometry using a detailed geometrical reference model of the subsurface (). Invert the synthetic seismic datasets preferably using simultaneous source FWI, and preferably with Volume of Investigation constraints, to determine model updates (). Quantitatively assess the value of the additional traces in a fuller dataset relative to a subset (), using one or more statistics based on the accuracy of the updated models, such as improved match to the reference model, better fit of seismic data, or rate of change in improvement with iterations. Inversions may be cascaded for further efficiency ().

Seismic survey design using full wavefield inversion

Method for performing simultaneous encoded-source inversion of geophysical data to estimate parameters of a physical property model (), especially adapted for surveys without fixed-receiver acquisition geometry, such as marine seismic surveys with moving source and receivers. The encoding functions () used on the sources to generate one or more simultaneous encoded-source gathers of data (), as well as to simulate the same (), are orthogonal or pseudo-orthogonal with respect to cross-correlation. In addition, receivers are also encoded, with the receiver encoding being designed to make a given receiver less sensitive to sources to which it was not listening during the survey (). The encoding functions may be temporal bandpass filters differing one from another by central frequency, phase, or both. Efficiency of the method may be further improved by grouping several sources into a super-source, grouping the corresponding gathers into a super-gather, and then applying the above encoding strategy.

Orthogonal source and receiver encoding

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Houston, TX, United States of America

Nathan Downey