Christopher Hugh Skelt

US Patent:

8116167, Feb 14, 2012

Filed:

Jun 12, 2008

Appl. No.:

12/137980

Inventors:

Paul A. Johnson - Santa Fe NM, US
James A. Ten Cate - Los Alamos NM, US
Robert Guyer - Reno NV, US
Pierre-Yves Le Bas - Los Alamos NM, US
Cung Vu - Houston TX, US
Kurt Nihei - Oakland CA, US
Denis P. Schmitt - Katy TX, US
Christopher Skelt - Houston TX, US

Assignee:

Chevron U.S.A. Inc. - San Ramon CA

International Classification:

G01V 1/50
G01V 1/44

US Classification:

367 32, 367 25, 181104, 7315202

Abstract:

A compact array of transducers is employed as a downhole instrument for acoustic investigation of the surrounding rock formation. The array is operable to generate simultaneously a first acoustic beam signal at a first frequency and a second acoustic beam signal at a second frequency different than the first frequency. These two signals can be oriented through an azimuthal rotation of the array and an inclination rotation using control of the relative phases of the signals from the transmitter elements or electromechanical linkage. Due to the non-linearity of the formation, the first and the second acoustic beam signal mix into the rock formation where they combine into a collimated third signal that propagates in the formation along the same direction than the first and second signals and has a frequency equal to the difference of the first and the second acoustic signals. The third signal is received either within the same borehole, after reflection, or another borehole, after transmission, and analyzed to determine information about rock formation. Recording of the third signal generated along several azimuthal and inclination directions also provides 3D images of the formation, information about 3D distribution of rock formation and fluid properties and an indication of the dynamic acoustic non-linearity of the formation.

US Patent:

8219319, Jul 10, 2012

Filed:

Dec 18, 2009

Appl. No.:

12/642632

Inventors:

Christopher Skelt - Houston TX, US

Assignee:

Chevron U.S.A. Inc. - San Ramon CA

International Classification:

G06F 19/00

US Classification:

702 7, 702 6, 702 9, 702 11, 702 13, 702 14, 703 6, 703 7, 73 7, 7315211, 7315218, 175 50, 367 27, 367 31

Abstract:

A computer-implemented method of characterizing elastic properties of a subsurface formation at various fluid saturation conditions is disclosed. The method includes the features of estimating densities and bulk moduli of fluids and surrounding rock matrix material present in an invaded zone around a wellbore and beyond the invaded zone to record a set of log curves of density and bulk modulus of the fluids and the surrounding rock matrix material present in the invaded zones and beyond the invaded zone versus depth; recording a set of shale trend compaction curves in each wellbore; solving a set of response equations for rock and fluid volumes based on the recorded set of log curves and shale trend compaction curves to compute lithology, porosity and hydrocarbon saturation to build computer models to estimate hydrocarbon saturation for the rock matrix material penetrated in the wellbore; and using the estimated densities and the bulk moduli of the fluids and the rock matrix material near the wellbore, the shale trend compaction curves and the computed lithology, porosity and hydrocarbon saturation near the wellbore to characterize elastic properties of a subsurface formation at various fluid saturation conditions.

US Patent:

8233349, Jul 31, 2012

Filed:

Aug 27, 2010

Appl. No.:

12/870440

Inventors:

Cung Khac Vu - Houston TX, US
Dipen N. Sinha - Los Alamos NM, US
Cristian Pantea - Los Alamos NM, US
Kurt T. Nihei - Oakland CA, US
Denis P. Schmitt - Katy TX, US
Christopher Skelt - Houston TX, US

Assignee:

Chevron U.S.A. Inc. - San Ramon CA

International Classification:

G01V 1/00
H04B 1/02

US Classification:

367 32, 367137

Abstract:

In some aspects of the invention, a device, positioned within a well bore, configured to generate and direct an acoustic beam into a rock formation around a borehole is disclosed. The device comprises a source configured to generate a first signal at a first frequency and a second signal at a second frequency; a transducer configured to receive the generated first and the second signals and produce acoustic waves at the first frequency and the second frequency; and a non-linear material, coupled to the transducer, configured to generate a collimated beam with a frequency equal to the difference between the first frequency and the second frequency by a non-linear mixing process, wherein the non-linear material includes one or more of a mixture of liquids, a solid, a granular material, embedded microspheres, or an emulsion.

US Patent:

8259530, Sep 4, 2012

Filed:

Aug 27, 2010

Appl. No.:

12/870604

Inventors:

Cung Khac Vu - Houston TX, US
Dipen N. Sinha - Los Alamos NM, US
Cristian Pantea - Los Alamos NM, US
Kurt T. Nihei - Oakland CA, US
Denis P. Schmitt - Katy TX, US
Christopher Skelt - Houston TX, US

Assignee:

Chevron U.S.A. Inc. - San Ramon CA

International Classification:

G01V 1/00

US Classification:

367 32

Abstract:

In some aspects of the invention, a device, positioned within a well bore, configured to generate and direct an acoustic beam into a rock formation around a borehole is disclosed. The device comprises a source configured to generate a first signal at a first frequency and a second signal at a second frequency; a transducer configured to receive the generated first and the second signals and produce acoustic waves at the first frequency and the second frequency; and a non-linear material, coupled to the transducer, configured to generate a collimated beam with a frequency equal to the difference between the first frequency and the second frequency by a non-linear mixing process, wherein the non-linear material includes one or more of a mixture of liquids, a solid, a granular material, embedded microspheres, or an emulsion.

US Patent:

8289808, Oct 16, 2012

Filed:

May 11, 2009

Appl. No.:

12/463796

Inventors:

Cung Vu - Houston TX, US
Kurt T. Nihei - Oakland CA, US
Denis P. Schmitt - Dhahran, SA
Christopher Skelt - Houston TX, US
Paul A. Johnson - Santa Fe NM, US
Robert Guyer - Reno NV, US
James A. TenCate - Los Alamos NM, US
Pierre-Yves Le Bas - Los Alamos NM, US

International Classification:

G01V 1/00

US Classification:

367 31, 367 35

Abstract:

In some aspects of the disclosure, a method for creating three-dimensional images of non-linear properties and the compressional to shear velocity ratio in a region remote from a borehole using a conveyed logging tool is disclosed. In some aspects, the method includes arranging a first source in the borehole and generating a steered beam of elastic energy at a first frequency; arranging a second source in the borehole and generating a steerable beam of elastic energy at a second frequency, such that the steerable beam at the first frequency and the steerable beam at the second frequency intercept at a location away from the borehole; receiving at the borehole by a sensor a third elastic wave, created by a three wave mixing process, with a frequency equal to a difference between the first and second frequencies and a direction of propagation towards the borehole; determining a location of a three wave mixing region based on the arrangement of the first and second sources and on properties of the third wave signal; and creating three-dimensional images of the non-linear properties using data recorded by repeating the generating, receiving and determining at a plurality of azimuths, inclinations and longitudinal locations within the borehole. The method is additionally used to generate three dimensional images of the ratio of compressional to shear acoustic velocity of the same volume surrounding the borehole.

US Patent:

8345509, Jan 1, 2013

Filed:

May 11, 2009

Appl. No.:

12/463802

Inventors:

Cung Vu - Houston TX, US
Kurt T. Nihei - Oakland CA, US
Denis P. Schmitt - Dhahran, SA
Christopher Skelt - Houston TX, US
Paul A. Johnson - Santa Fe NM, US
Robert Guyer - Reno NV, US
James A. TenCate - Los Alamos NM, US
Pierre-Yves Le Bas - Los Alamos NM, US

Assignee:

Chevron U.S.A., Inc. - San Ramon CA
Los Alamos National Security - Los Alamos NM

International Classification:

G01V 1/44
G01V 1/50
G01S 1/72

US Classification:

367 32, 367 49, 367 57, 367 72, 367117

Abstract:

In some aspects of the disclosure, a method for creating three-dimensional images of non-linear properties and the compressional to shear velocity ratio in a region remote from a borehole using a conveyed logging tool is disclosed. In some aspects, the method includes arranging a first source in the borehole and generating a steered beam of elastic energy at a first frequency; arranging a second source in the borehole and generating a steerable beam of elastic energy at a second frequency, such that the steerable beam at the first frequency and the steerable beam at the second frequency intercept at a location away from the borehole; receiving at the borehole by a sensor a third elastic wave, created by a three wave mixing process, with a frequency equal to a difference between the first and second frequencies and a direction of propagation towards the borehole; determining a location of a three wave mixing region based on the arrangement of the first and second sources and on properties of the third wave signal; and creating three-dimensional images of the non-linear properties using data recorded by repeating the generating, receiving and determining at a plurality of azimuths, inclinations and longitudinal locations within the borehole. The method is additionally used to generate three dimensional images of the ratio of compressional to shear acoustic velocity of the same volume surrounding the borehole.

US Patent:

8547790, Oct 1, 2013

Filed:

Jun 3, 2010

Appl. No.:

12/793414

Inventors:

Cung Khac Vu - Houston TX, US
Dipen N. Sinha - Los Alamos NM, US
Cristian Pantea - Los Alamos NM, US
Kurt T. Nihei - Oakland CA, US
Denis P. Schmitt - Katy TX, US
Christopher Skelt - Houston TX, US

Assignee:

Chevron U.S.A. Inc. - San Ramon CA
Los Alamos National Security LLC - Los Alamos NM

International Classification:

G01V 1/00

US Classification:

367 32

Abstract:

In some aspects of the invention, a method of generating a beam of acoustic energy in a borehole is disclosed. The method includes generating a first acoustic wave at a first frequency; generating a second acoustic wave at a second frequency different than the first frequency, wherein the first acoustic wave and second acoustic wave are generated by at least one transducer carried by a tool located within the borehole; transmitting the first and the second acoustic waves into an acoustically non-linear medium, wherein the composition of the non-linear medium produces a collimated beam by a non-linear mixing of the first and second acoustic waves, wherein the collimated beam has a frequency based upon a difference between the first frequency and the second frequency; and transmitting the collimated beam through a diverging acoustic lens to compensate for a refractive effect caused by the curvature of the borehole.

US Patent:

8547791, Oct 1, 2013

Filed:

Jun 3, 2010

Appl. No.:

12/793420

Inventors:

Cung Khac Vu - Houston TX, US
Dipen N. Sinha - Los Alamos NM, US
Cristian Pantea - Los Alamos NM, US
Kurt T. Nihei - Oakland CA, US
Denis P. Schmitt - Katy TX, US
Christopher Skelt - Houston TX, US

Assignee:

Chevron U.S.A. Inc. - San Ramon CA
Los Alamos National Security LLC - Los Alamos NM

International Classification:

G01V 1/00

US Classification:

367 32

Abstract:

In some aspects of the invention, a method of generating a beam of acoustic energy in a borehole is disclosed. The method includes generating a first broad-band acoustic pulse at a first broad-band frequency range having a first central frequency and a first bandwidth spread; generating a second broad-band acoustic pulse at a second broad-band frequency range different than the first frequency range having a second central frequency and a second bandwidth spread, wherein the first acoustic pulse and second acoustic pulse are generated by at least one transducer arranged on a tool located within the borehole; and transmitting the first and the second broad-band acoustic pulses into an acoustically non-linear medium, wherein the composition of the non-linear medium produces a collimated pulse by a non-linear mixing of the first and second acoustic pulses, wherein the collimated pulse has a frequency equal to the difference in frequencies between the first central frequency and the second central frequency and a bandwidth spread equal to the sum of the first bandwidth spread and the second bandwidth spread.

Address:

10219 Inwood Dr, Houston, TX 77042

VIN:

5J8TB2H27BA001217

Make:

ACURA

Model:

RDX

Year:

2011