Geophysical prospecting
AssigneeExxon Production Research Company
InventorsArthur Howard Thompson, Grant Alan Gist
Life of this patent
Estimating the term…
Abstract
Method and apparatus are provided for a new type of geophysical prospecting. The method applies an electric field to a fluid-containing porous subsurface formation to create a fluid pulse from changes in the polarization of pore fluid dipoles. The fluid pulse propagates in the subsurface as a seismic wave that may be detected by an appropriate array of seismic detectors. The apparatus is a pulsed DC or AC source for generating an applied electric field and a seismic detector.
Claims29
A method for geophysical prospecting of a preselected subsurface region, comprising;
- generating an electric field of sufficient strength to penetrate said preselected region to a depth of interest,
- converting said electric field to a seismic wave in at least one porous subsurface earth formation in said preselected region containing at least one fluid, and
- detecting said seismic wave with a seismic detector.
A method for logging subsurface formations penetrated by a borehole, comprising:
- generating an electric field within said borehole with a power source,
- converting said electric field to a seismic wave at a porous subsurface earth formation adjacent said borehole containing at least one fluid, and
- detecting said seismic wave within said borehole with a seismic detector.
A method for generating seismic energy in a preselected subsurface region of the earth, comprising:
- generating an electric field of sufficient strength to penetrate said preselected region to a depth of interest, and
- converting said electric field to a seismic wave at a porous subsurface earth formation in said preselected region containing at least one fluid.
Apparatus for geophysical prospecting, comprising:
- means for generating an electric field, and
- means for detecting a seismic wave which has resulted from the conversion of an electric field in at least one porous subsurface earth formation containing at least one fluid.
A method for cross-borehole tomography, comprising,
- generating an electric field in a first borehole penetrating the earth,
- converting said electric field to a seismic wave in at least one porous subsurface earth formation adjacent said first borehole and containing at least one fluid, and
- detecting said seismic wave in a second borehole penetrating the earth and spaced from said first borehole.
A method for geophysical prospecting of a preselected subsurface region, comprising:
- (a) generating an electric field of sufficient strength to penetrate said region to a depth of interest,
- (b) detecting a seismic wave generated by said electric field interacting with fluid dipoles in at least one first porous subsurface earth formation in said region,
- (c) generating a seismic wave of sufficient strength to penetrate said region to a depth of interest,
- (d) detecting an electric field generated by said seismic wave interacting with fluid dipoles in at least one second porous subsurface earth formation in said region, and
- (e) wherein steps (a) and (b) may be performed after or before steps (c) and (d).
A method for logging subsurface formations penetrated by a borehole, comprising:
- (a) generating an electric field within said borehole with a power source,
- (b) detecting a seismic wave resulting from said electric field generated in said borehole interacting with fluid dipoles in at least one first porous subsurface earth formation adjacent said borehole,
- (c) generating a seismic wave within said borehole, and
- (d) detecting an electric field resulting from said seismic wave generated in said borehole interacting with fluid dipoles in at least one second porous subsurface earth formation adjacent said borehole, and
- (e) wherein steps (a) and (b) may be performed after or before steps (c) and (d).
Dependencies are inferred from the claim text.