Patent ID: 8242781
Filing Date: 2012-08-14
Classification: E21B,Y10T

Abstract:
1. A method for determining subsurface geological features at an existing oil well site having a well bore disposed through strata to a given subsurface layer depth for recovering crude oil in a fluid reservoir at said subsurface depth but horizontally remote from said well bore, the method comprising: a) from multiple positions on the terrain surface, transmitting immediately in the far field a sequence of pulsed electromagnetic energy beam signals focused at a target depth, wherein the signals combine to cover a target area of a formation layer that lies between the terrain surface and said given subsurface layer containing the fluid reservoir defining a scan, the target area having a center offset horizontally from the well bore; b) receiving reflections from the target area in response to the sequence of transmitted pulsed energy beam signals impinging thereon, the reflections being characteristic of particular media located within the target area being impinged upon by the immediately transmitted far field pulsed electromagnetic energy beam signals; c) correlating the received reflections from said target area over a given time interval for a given scan to determine relative changes in intensities of reflections over said target area for a given scan; d) storing the scan data for each scan in memory; modifying transmit parameters in at least one of frequency, focus depth, and phase shift and repeating steps a)-d) to generate volume data for each layer up to said given subsurface layer; identifying particular media and their location within the volume according to the scan data, wherein the identifying includes identifying the location of crude oil relative to other of the particular media.