Ping Linda Zhang

US Patent:

6985019, Jan 10, 2006

Filed:

Apr 13, 2004

Appl. No.:

10/823450

Inventors:

Ping Zhang - Sunnyvale CA, US
Ronald L. Cline - Albuquerque NM, US

Assignee:

Xilinx, Inc. - San Jose CA

International Classification:

H03K 5/08

US Classification:

327309

Abstract:

A selectively enabled clamp circuit for limiting voltage overshoot on an input/output (I/O) pin of an associated integrated circuit (IC) device includes a single discharge transistor and a select circuit. The single discharge transistor is connected between the I/O pin and ground potential, and the select circuit is coupled to the I/O pin and includes an input to receive an enable signal and an output coupled to a gate of the signal discharge transistor. For some embodiments, the select circuit includes a level shifter circuit and a voltage detection circuit.

US Patent:

7049821, May 23, 2006

Filed:

May 29, 2003

Appl. No.:

10/250030

Inventors:

Eldad Haber - Freemont CA, US
Ping Zhang - Albany CA, US

Assignee:

Schlumberger Technology Corporation - Sugar Land TX

International Classification:

G01V 3/08
G01V 3/26

US Classification:

324339, 324326, 324343, 324372, 32420717

Abstract:

A method is disclosed for locating a receiver in a borehole having a conductive liner by inducing an electromagnetic field from a transmitter in a first borehole, detecting at a first location by at least one receiver located in a second borehole having a conductive liner, a first electromagnetic field induced by the transmitter, detecting at a second location by the at least one receiver, a second electromagnetic field induced by the transmitter and calculating a set of geometry coordinates for the first location based on the first electromagnetic field and the second electromagnetic field.

US Patent:

7095232, Aug 22, 2006

Filed:

Apr 4, 2005

Appl. No.:

11/098073

Inventors:

Eldad Haber - Freemont CA, US
Ping Zhang - Albany CA, US

Assignee:

Schlumberger Technology Corporation - Sugar Land TX

International Classification:

G01V 3/08
G01V 3/26

US Classification:

324368, 324339, 324372

Abstract:

A method is disclosed for locating a receiver in a borehole having a conductive liner by inducing an electromagnetic field from a transmitter in a first borehole, detecting at a first location by at least one receiver located in a second borehole having a conductive liner, a first electromagnetic field induced by the transmitter, detecting at a second location by the at least one receiver, a second electromagnetic field induced by the transmitter and calculating a set of geometry coordinates for the first location based on the first electromagnetic field and the second electromagnetic field.

US Patent:

7565244, Jul 21, 2009

Filed:

Jun 27, 2007

Appl. No.:

11/768975

Inventors:

David Alumbaugh - Berkeley CA, US
Ping Zhang - Albany CA, US
Edward Nichols - Berkeley CA, US
Frank Morrison - Berkeley CA, US
Aria Abubakar - North Reading MA, US
Tarek Habashy - Burlington MA, US

Assignee:

Schlumberger Technology Corporation - Sugar Land TX

International Classification:

G01V 1/40

US Classification:

702 6, 702 7, 702 11, 324323, 324334, 324339, 367 29, 367 49

Abstract:

Characterizing a reservoir with electromagnetic imaging surveys includes normalizing measured voltage data by transmitter moment, sorting the normalized voltage data into common receiver profiles, densely resampling transmitter locations using common positions for the receiver profiles, coarsely resampling the data at discreet transmitter locations, defining a starting model for inversion, weighting the data by a factor, converting the normalized voltage data to ratios, calculating a conductivity image using a ratio inversion method, and verifying that an inversion has converged and the image is geologically reasonable. The image can then be displayed. The invention can be used for cross-well, surface-to-borehole, and borehole-to-surface measurements by which the effects of steel casing are reduced.

US Patent:

7991553, Aug 2, 2011

Filed:

Jun 19, 2008

Appl. No.:

12/142408

Inventors:

David Alumbaugh - Berkeley CA, US
Ping Zhang - Albany CA, US
Edward Nichols - Berkeley CA, US
Frank Morrison - Berkeley CA, US
Aria Abubakar - North Reading MA, US
Tarek Habashy - Burlington MA, US

Assignee:

Schlumberger Technology Corporation - Sugar Land TX

International Classification:

G01V 1/40

US Classification:

702 6, 702 7, 702 11, 324323, 324334, 324339, 367 29, 367 49

Abstract:

Characterizing a reservoir with electromagnetic imaging surveys includes normalizing measured voltage data by transmitter moment, sorting the normalized voltage data into common receiver profiles, densely resampling transmitter locations using common positions for the receiver profiles, coarsely resampling the data at discreet transmitter locations, defining a starting model for inversion, weighting the data by a factor, converting the normalized voltage data to ratios, calculating a conductivity image using a ratio inversion method, and verifying that an inversion has converged and the image is geologically reasonable. The image can then be displayed. The invention can be used for cross-well, surface-to-borehole, borehole-to-surface, and single-well (borehole-to-borehole) measurements measurements by which the effects of steel casing are reduced.

US Patent:

20080281667, Nov 13, 2008

Filed:

May 7, 2007

Appl. No.:

11/745181

Inventors:

Jiuping Chen - Albany CA, US
Ping Zhang - Albany CA, US
Michael Wilt - Walnut Creek CA, US
Edward Nichols - Berkeley CA, US
David Alumbaugh - Berkeley CA, US

Assignee:

SCHLUMBERGER TECHNOLOGY CORPORATION - Sugar Land TX

International Classification:

G06F 17/30

US Classification:

705 10

Abstract:

A technique that is usable with a well includes providing a model so predict measurements that are received by receivers due to transmission by sources baaed on estimated positions of the receivers relative to sources. The estimated positions each have at least two dimensions. At least some of the receivers and the sources are located in the well. On a computer, the estimated positions are automatically refined based on a comparison of the predicted measurements and actual measurements that are obtained by the receivers.

US Patent:

20090150124, Jun 11, 2009

Filed:

Dec 7, 2007

Appl. No.:

11/952654

Inventors:

Michael Wilt - Abu Dhabi, AE
Herve Denaclara - Bourg-Madame, FR
Ping Zhang - Albany CA, US
David Alumbaugh - Berkeley CA, US
Thor Johnsen - Pleasanton CA, US

Assignee:

SCHLUMBERGER TECHNOLOGY CORPORATION - Cambridge MA

International Classification:

G06F 17/50
G06G 7/50

US Classification:

703 1, 703 10

Abstract:

One embodiment of the invention involves a method for determining whether an electromagnetic survey will be able to distinguish between different subsurface conditions in an area that includes developing a three-dimensional electromagnetic property model of the area, and simulating an electromagnetic response of a field electromagnetic data acquisition system using the three-dimensional electromagnetic property model to determine if expected differences in an electromagnetic response of a electromagnetic data acquisition system are within detectability limits of the system. Another embodiment involves a model-based method of inverting electromagnetic data associated with a subsurface area that includes developing a three-dimensional electromagnetic property model of the area, and restricting changes that may be made to the model during the electromagnetic data inversion process. Other related embodiments of the inventive method are also described and claimed.

US Patent:

20120191353, Jul 26, 2012

Filed:

Apr 3, 2012

Appl. No.:

13/438763

Inventors:

MICHAEL WILT - WALNUT CREEK CA, US
HERVE DENACLARA - BOURG-MADAME, FR
PING ZHANG - ALBANY CA, US
DAVID ALUMBAUGH - BERKELEY CA, US
THOR JOHNSEN - DUBLIN CA, US

International Classification:

G06F 19/00
G01V 3/12
G06G 7/48

US Classification:

702 6, 703 10

Abstract:

One embodiment of the invention involves a model-based method of inverting electromagnetic data associated with a subsurface area that includes developing a three-dimensional electromagnetic property model of the area, and restricting changes that may be made to the model during the electromagnetic data inversion process. Other related embodiments of the inventive method are also described and claimed.