Leonty A Tabarovsky

US Patent:

6353322, Mar 5, 2002

Filed:

Jun 9, 1998

Appl. No.:

09/094220

Inventors:

Leonty Abraham Tabarovsky - Houston TX
Gregory Boris Itskovich - Houston TX

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

G01V 320

US Classification:

324366, 324358, 324371

Abstract:

A method for determining the resistivity of earth formations penetrated by a wellbore. Electrical current is imparted to the wellbore and the earth formations from a first electrode located on a mandrel disposed in the wellbore. The electrical current is returned at a second electrode on the mandrel at a spaced apart location from the first electrode. Voltage differences are measured between a first pair and a second pair of electrodes located on the mandrel between the first and the second electrodes. Circuits used to measure the voltage differences are adjusted until the measured voltage difference between the second pair is substantially the same as the measured voltage difference between the first pair. Then the electrical current is returned to an electrode at the earths surface or other location distal from the first electrode, and measuring the voltage differences is repeated. A difference of the voltage differences is then calculated.

US Patent:

6574562, Jun 3, 2003

Filed:

Apr 3, 2001

Appl. No.:

09/825104

Inventors:

Leonty A. Tabarovsky - Houston TX
Michael B. Rabinovich - Houston TX

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

G01V 140

US Classification:

702 7, 702 6

Abstract:

Skin-effect corrections are applied to measurements made by a transverse induction logging tool to give corrected measurements indicative of vertical conductivities of a formation. Data from a conventional induction logging tool are inverted or focused to give an isotropic model of formation resistivity. A forward modeling is used to derive from the isotropic model measurements that would be expected with a transverse induction logging tool. Skin-effect corrections are applied to these expected measurements. The formation anisotropy is determined from the skin-effect corrected transverse induction measurements, the skin-effect corrected expected measurements and from the isotropic model conductivities.

US Patent:

6636045, Oct 21, 2003

Filed:

Feb 7, 2002

Appl. No.:

10/072173

Inventors:

Leonty A. Tabarovsky - Houston TX
Mikhail Epov - Novosibirsk, RU
Michael B. Rabinovich - Houston TX

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

G01V 318

US Classification:

324343, 702 7

Abstract:

Measurements are made with a multicomponent induction logging tool in earth formations in a borehole inclined to earth formations. A combination of principal component measurements is used to determine the horizontal resistivity of the earth formations. The determined horizontal resistivities are used in a model for inversion of other components of the data to obtain the vertical formations resistivities. When multifrequency measurements are available, frequency focusing is used.

US Patent:

6643589, Nov 4, 2003

Filed:

Mar 5, 2002

Appl. No.:

10/091310

Inventors:

Zhiyi Zhang - Houston TX
Liming Yu - Stafford TX
Leonty Abraham Tabarovsky - Houston TX
Berthold Kriegshauser - Houston TX

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

G01V 318

US Classification:

702 7, 702 10

Abstract:

Measurements made by a multicomponent logging tool in a borehole are inverted to obtain horizontal and vertical resistivities and formation dip and azimuth angles of a formation traversed by the borehole. The inversion is performed using a generalized Marquardt-Levenberg method. In this generalized Marquardt-Levenberg method, a data objective function is defined that is related to a difference between the model output and the measured data. The iterative procedure involves reducing a global objective function that is the sum of the data objective function and a model objective function related to changes in the model in successive iterations. In an alternate embodiment of the invention, the formation azimuth angle is excluded from the iterative process by using derived relations between the multicomponent measurements.

US Patent:

6809521, Oct 26, 2004

Filed:

Jan 17, 2003

Appl. No.:

10/347019

Inventors:

Leonty Abraham Tabarovsky - Houston TX
Albert Alexy - Katy TX

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

G01V 320

US Classification:

324374, 324375

Abstract:

A resistivity device for downhole use with a nonconducting mud injects a current at a frequency sufficiently high to pass capacitively through the mud and a mud cake into the formation. The frequency is further selected so that the impedance due to the dielectric constant of the formation is small compared to the formation resistivity. Dual frequency measurements may be used to further minimize the effects of the mud and mud cake resistivity. When multiple frequency measurements are used, frequency focusing may be used to get an estimate of formation resistivity that is independent of near borehole effects.

US Patent:

6906521, Jun 14, 2005

Filed:

Nov 15, 2002

Appl. No.:

10/295969

Inventors:

Leonty Tabarovsky - Houston TX, US

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

G01V001/40

US Classification:

324334, 702 7

Abstract:

An induction logging tool is used on a MWD bottom hole assembly. Due to the finite, nonzero, conductivity of the mandrel, conventional multi frequency focusing (MFF) does not work. A correction is made to the induction logging data to give measurements simulating a perfectly conducting mandrel. MFF can then be applied to the corrected data to give formation resistivities.

US Patent:

7027922, Apr 11, 2006

Filed:

Aug 25, 2003

Appl. No.:

10/647483

Inventors:

Alexander Bespalov - Spring TX, US
Michael Rabinovich - Houston TX, US
Leonty A. Tabarovsky - Cypress TX, US

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

G01V 1/40

US Classification:

702 7, 702 14, 703 5

Abstract:

A method is discussed of obtaining a parameter of interest of an earth formation, typically a formation resistivity or a distance to a bed boundary, in conditions where an induction tool is using having a body with finite, non-zero conductivity. The method substantially removes the effects of the conductivity of the tool from the signal received from the earth formation. A Taylor series expansion in one half of odd integer powers of time is used to represent the received signal. At least one leading term of the Taylor series expansion can be subtracted from the second signal. A filtering operation is applied to the second signal to remove the terms most dominated by pipe effects. Typical filtering operations can be a differential filtering operation or an integral filtering operation.

US Patent:

7031839, Apr 18, 2006

Filed:

Sep 3, 2004

Appl. No.:

10/934596

Inventors:

Leonty A. Tabarovsky - Cypress TX, US
Alexandre N. Bespalov - Spring TX, US
Stanislav W. Forgang - Houston TX, US
Michael B. Rabinovich - Houston TX, US

Assignee:

Baker Hughes Incorporated - Houston TX

International Classification:

G01V 1/40
G01V 3/18
G01V 5/04
G01V 9/00
G06F 19/00

US Classification:

702 7, 702 6, 324328, 324329, 324330, 324331, 324332, 324333, 324334, 324335, 324336, 324337, 324338, 324339, 324340, 324341, 324342, 324343, 324344, 324345, 324346

Abstract:

An induction logging tool is used on a MWD bottom hole assembly. Due to the finite, nonzero, conductivity of the mandrel, conventional multi frequency focusing (MFF) does not work. A correction is made to the induction logging data to give measurements simulating a perfectly conducting mandrel. MFF can then be applied to the corrected data to give formation resistivities.