Long H Pham

US Patent:

6442490, Aug 27, 2002

Filed:

Jun 30, 2000

Appl. No.:

09/607272

Inventors:

Jianchao Li - Houston TX
Long Don Pham - Houston TX

Assignee:

PGS Americas, Inc. - Houston TX

International Classification:

G06F 1900

US Classification:

702 18, 703 10

Abstract:

A method for processing three-dimensional seismic data is provided. The seismic data is at least partially the result of receiving a seismic wave with a seismic receiver. At least a portion of the seismic wave is generated by a seismic source. The source and receiver are both horizontally offset and vertically offset. The method comprises binning at least a portion of the seismic data in common reflection point bins. The method comprises sorting the seismic data within the bin to create common reflection point gathers. The method further comprises analyzing velocity, and applying surface consistent statics corrections to at least a portion of the seismic data within said common reflection point gathers. The method also comprises applying a non-hyperbolic normal moveout equation to at least a portion of said seismic data, and stacking at least a portion of said seismic data within said common reflection point gathers.

US Patent:

55218814, May 28, 1996

Filed:

Sep 2, 1994

Appl. No.:

8/300474

Inventors:

Yiu-Wa A. Lau - Houston TX
Long D. Pham - Houston TX

Assignee:

Exxon Production Research Company - Houston TX

International Classification:

G01V 122

US Classification:

367 24

Abstract:

Disclosed is a method of processing seismic data containing multiples, which method generally includes as a step, determining the two-way travel time to a suspected multiple generating event. This method includes the application of a normal moveout operation to the recorded seismic trace utilizing the primary event velocities. Once the normal moveout has been applied to the data, all of the events in the trace are shifted downward in time by an amount of time equal to the two-way travel time to the suspected multiple generating event as previously determined. Once the normal moveout operation and the two-way travel time shift have been applied to the trace, a reverse normal moveout operation is applied to the trace utilizing an extended velocity function, which is a function of the original primary and the velocity within the suspected multiple generating layer. The resulting trace is now a trace containing only multiples. Finally, the multiple noise is subtracted from the original data utilizing an amplitude scaling factor and a residual time shift.

US Patent:

54023920, Mar 28, 1995

Filed:

Aug 10, 1993

Appl. No.:

8/104444

Inventors:

Chih-Ping J. Lu - Sugar Land TX
Long D. Pham - Houston TX

Assignee:

Exxon Production Research Company - Houston TX

International Classification:

G01V 140

US Classification:

367 75

Abstract:

The orientation of vertical fractures in subsurface rock formations is determined. A cross-dipole logging tool collects four-component shear-wave seismic data through a formation interval of interest in a subsurface formation adjacent a well bore. A gyroscope is typically provided to indicate compass orientation of the logging tool. The collected seismic data are then transformed within a time window containing arrivals of the shear waves to a new coordinate system within which the motion of the shear waves becomes linear. In the new coordinate system, the shear wave data are processed to determine the presence and orientation of fractures in the formation.

US Patent:

59783141, Nov 2, 1999

Filed:

Mar 21, 1997

Appl. No.:

8/821551

Inventors:

Long Don Pham - Houston TX

Assignee:

Exxon Production Research Company - Houston TX

International Classification:

G01V 136

US Classification:

367 52

Abstract:

A method for determining a substantially optimal NMO velocity function for use in stacking a CMP gather of seismic data traces. The method begins with an initial estimate of the NMO velocity function for the CMP gather. This initial estimate is typically determined through conventional seismic velocity analysis. The method then picks a first velocity-traveltime pair falling on the initial estimate of the NMO velocity function and conducts a two-dimensional interpolative search of trial velocity-traveltime pairs in the neighborhood of the pick to find a substantially optimal velocity-traveltime pair. This substantially optimal velocity-traveltime pair is the trial velocity-traveltime pair having the highest stack response and is substituted for the pick in the NMO velocity function. The method then proceeds to find substantially optimal velocity-traveltime pairs to replace each of the other picks on the initial estimate of the NMO velocity function. Preferably, the two-dimensional interpolative search consists of a one-dimensional parabolic interpolative search to identify the optimal velocity for each computational time within a specified time window, followed by a one-dimensional search to select one of these optimal velocities which, together with its corresponding computational time, becomes the substantially optimal velocity-traveltime pair for the pick in question.

US Patent:

6112155, Aug 29, 2000

Filed:

Mar 3, 1998

Appl. No.:

9/029689

Inventors:

Long Don Pham - Houston TX

Assignee:

Exxon Production Research Company - Houston TX

International Classification:

G06F 1900

US Classification:

702 14

Abstract:

This invention is a method of attenuating multiples in seismic data, particularly three-dimensional seismic data in which seafloor roughness is present. The method relies on an efficient ray-tracing procedure to determine travel-times for each multiple. The characteristics of the seismic data are used to estimate the waveform of the multiple to be attenuated. The travel-time and the estimated waveform are then used to attenuate the multiple from the original data. The method can be employed both for water-bottom multiples and for source and receiver pegleg multiples.