Arcangelo Gabriele Sena

US Patent:

7082367, Jul 25, 2006

Filed:

Jul 2, 2004

Appl. No.:

10/884579

Inventors:

Bradley L. Bankhead - Houston TX, US
Arcangelo G. Sena - Houston TX, US

Assignee:

Veritas DGC Inc. - Houston TX

International Classification:

G01V 1/28
G01V 1/00

US Classification:

702 14, 367 73

Abstract:

Disclosed herein are systems and methods for calibrating seismic data using seismic attribute pairs such as amplitude versus offset (AVO) attributes. In one embodiment, a method includes: receiving traces from a seismic survey that covers a volume; determining a pair of seismic attributes for each of a plurality of positions within the volume (“survey pairs”); deriving pairs of seismic attributes from a source independent of the survey (“independent pairs”); calculating a rotation angle and one or more scale factors that calibrate the survey pairs relative to the independent pairs; and calibrating the traces with the rotation angle and the one or more scale factors. Thus, for example, the overall amplitude and relative AVO of pre-stack seismic gathers can be calibrated to match that of synthetic gathers by matching crossplots of AVO attributes generated from each dataset.

US Patent:

57843341, Jul 21, 1998

Filed:

Mar 13, 1996

Appl. No.:

8/614744

Inventors:

Arcangelo G. Sena - Plano TX
Herbert W. Swan - Richardson TX

Assignee:

Atlantic Richfield Company - Los Angeles CA

International Classification:

G01V 130
G01V 128

US Classification:

367 47

Abstract:

A computer-operated method for analyzing seismic data to discern the presence of hydrocarbon-bearing formations is disclosed. According to the disclosed method and system, amplitude-versus-offset (AVO) analysis is performed to assign, for each depth point in a survey region, an AVO intercept value and an AVO gradient value; the AVO intercept value corresponds to the zero-offset response for acoustic reflections from the depth point, while the AVO gradient value corresponds to the rate of change of the amplitude as a function of the angle of incidence of the acoustic energy (typically, with the square of the sine of the angle). An AVO indicator indicative of the presence of hydrocarbons at a subsurface stratum is derived to correspond to the rate of change of the product of the AVO intercept value and the AVO gradient value for the depth point under analysis, along the direction of a deviation vector of the AVO intercept value and the AVO gradient value from a background trend for depth points surrounding the depth point under analysis in time and space. The background trend, and thus the deviations, may be a straight line in a space having AVO intercept value and AVO gradient value as axes, or may be a statistical trend used in deriving the deviations. Use of the disclosed method and system has been observed to indicate deep hydrocarbon-bearing formations that are not detectable using conventional AVO analysis.