Rock Solid Images, Inc.

Ohm, Inc.

Peter Harris

Lucy MacGregor

Joel D Walls

A method of analyzing controlled source electromagnetic (CSEM) survey data to determine probability density functions (PDFs) for values of an electromagnetic parameter at locations in a subterranean region of interest is provided. Structural features in the subterranean strata are identified, e.g. from seismic survey data. An initial PDF for values of the electromagnetic parameter is then assigned to each feature. Models specifying values for the parameter in each structural feature are generated by sampling the PDFs. A subset of the models are deemed acceptable based on an acceptance criterion. The PDF for each feature is modified based on values for the parameter in the subset of accepted models to generate replacement PDFs for each feature. The process may be iterated a number of times to generate final PDFs for values of the electromagnetic parameter in the structural features identified in the subterranean region of interest.

Geophysical surveying

A method for mapping a property of a subsurface reservoir includes determining a value of at least one reservoir property from measurements obtained from a well drilled through the reservoir. A relationship is determined between the at least one property of the reservoir and at least one seismic attribute and at least one electromagnetic survey attribute at a geodetic position of the well. A value of the at least one reservoir property is determined at at least one other geodetic position from a value of the at least one seismic attribute, a value of the at least one electromagnetic survey attribute at the at least one other geodetic position, and from the determined relationship.

Method for interpreting seismic data and controlled source electromagnetic data to estimate subsurface reservoir properties

Joint processing of seismic and controlled source electromagnetic (CSEM) surface data is performed by using a common rock physics model which relates reservoir properties (such as porosity, lithology, saturation, and shaliness) to surface seismic AVO (or AVA) data. This allows one to determine how perturbations in the reservoir properties affect surface data. This can be carried out by systematically changing the reservoir properties and examining the effect on the synthetic data. This allows the hydrocarbon type of a reservoir to be established, e.g. oil or gas, as well as the saturation level of the hydrocarbon in the reservoir, which is useful for determining whether the reservoir has a non-commercial, low hydrocarbon saturation or a commercial, high hydrocarbon saturation.

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Oslo, Norway

Peter Harris