Providing measurements to enable determination of electrical resistivity anisotropy of a subterranean structure
AssigneeWesternGeco L.L.C.
InventorsMichael Tompkins, David L. Alumbaugh
Life of this patent
Estimating the term…
Abstract
To analyze content of a subterranean structure, electric field measurements at plural source-receiver azimuths in a predefined range are received. Total magnetic field measurements are also received at plural source-receiver azimuths in the predefined range. The electric field measurements and the total magnetic field measurements are provided to an analysis module to enable determination of electrical resistivity anisotropy of the subterranean structure.
Claims16
A method of analyzing content of a subterranean geological structure, comprising:
- receiving, by a computer, first data corresponding to electric field measurements at plural source-receiver azimuths in a predefined range;
- receiving, by the computer, second data corresponding to total magnetic field measurements at plural source-receiver azimuths in the predefined range;
- wherein the received first and second data corresponding to the electric field measurements and the total magnetic field measurements are acquired using electromagnetic (EM) receivers carried by a plurality of cables towed by at least one marine vessel, at least two of the plurality of cables also carrying respective EM sources, and
- wherein the azimuths are defined between the EM sources and the EM receivers carried by the cables;
- and
- providing the first data and the second data to an analysis module executed in the computer to determine electrical resistivity anisotropy of the subterranean geological structure.
A system for surveying a subterranean geological structure, comprising:
- a plurality of cables carrying electromagnetic (EM) receivers;
- EM sources arranged on at least two of the plurality of cables, wherein the plurality of cables are configured to be towed through a body of water generally along a first direction such that a limited range of azimuths are provided between the EM sources and the EM receivers,
- wherein the EM receivers are configured to acquire electric field measurement data and total magnetic field measurement data at plural source-receiver azimuths in the limited range of azimuths, and
- wherein the electric field measurement data and the total magnetic field measurement data are provided to a controller to determine an electrical resistivity anisotropy of the subterranean structure.
An article comprising at least one non-transitory computer-readable storage medium containing instructions that upon execution by a processor causes the processor to:
- receive first data corresponding to electric field measurements acquired at plural source-receiver azimuths in a predefined range;
- receive second data corresponding to total magnetic field measurements acquired at plural source-receiver azimuths in the predefined range,
- wherein the received first and second data correspond to the electric field measurements and the total magnetic field measurements acquired using electromagnetic (EM) receivers carried by a plurality of cables towed by at least one marine vessel, at least two of the plurality of cables also carrying EM sources, and wherein the azimuths are defined between the respective EM sources and the EM receivers carried by the cables;
- and
- process the first data and the second data to determine an electrical resistivity anisotropy of a subterranean geological structure.
Dependencies are inferred from the claim text.