Baker Hughes Corporation

Halliburton Energy Services, Inc.

Halliburton Company

Halliburton Logging Services, Inc.

Gulamabbas A Merchant

Otto N Fanini

Tsili Wang

Robert W Strickland

Michael Rabinovich

Randal Thomas Beste

Luis M Pelegri

Liming Yu

Berthold Kriegshauser

Bill H Corley

Kenneth Babin

Stanislav W Forgang

Randy Gold

Roland Edward Chemali

Alexandre N Bespalov

Sheng Fang

Larry L Gadeken

Andrew Kirkwood

Wallace Harold Meyer

Cynthia Xue

Suresh G Thadani

Stephen V Painchaud

Eric Hart

Luis Emilio San Martin

Dingding Chen

Andrew G Brooks

Larry Alan Jacobson

Jiaqi Xiao

Paul Gerard Cairns

Hugh E Hall, Jr

Frank R Bravenec

Vladimir S Mogilatov

Martin T Hagan

Herbert Max Illfelder

Charles E Jackson

Edwinus Nicolaas Maria Quint

Measurements made with a multicomponent logging system oriented in a horizontal position above the surface of the earth must satisfy certain relationships. These relationships are used to establish calibration errors in the system.

Calibration of XX, YY and ZZ induction tool measurements

A method for providing an image of a formation surrounding a wellbore, includes: obtaining an apparent conductivity curve from main components of resistivity measurements of the formation; performing fitting for cross-components of the resistivity measurements; calculating scaling factors from the cross-component data; scaling apparent conductivity data by the calculated scaling factors; and plotting the scaled conductivity data to provide the image of the anisotropic formation. A system and a computer program product are disclosed.

Anisotropy orientation image from resistivity measurements for geosteering and formation evaluation

Cross-component measurements in combination with standard propagation resistivity measurements are processed to estimate the vertical and horizontal resistivities, relative dip and relative azimuth of an anisotropic earth formation.

Determining structural dip and azimuth from LWD resistivity measurements in anisotropic formations

A method of evaluating an earth formation is disclosed which includes conveying a logging tool into a borehole in the earth formation and using the logging tool to obtain a first set of azimuthally-independent resistivity measurements of the earth formation and a second set of azimuthally-sensitive resistivity measurements of the earth formation and estimating a value of a property of the earth formation using the first set of measurements and the second set of measurements, the estimation being substantially unaffected by a displacement of the logging tool from a center of the borehole.

Apparatus and method for estimating eccentricity effects in resistivity measurements

A phase error in measurements made by a resistivity logging tool is estimated by positioning the tool above a conducting surface. Deviation of the measured phase difference between the transmitter and the receiver from 90&#xb0; gives the phase error in the electronics. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Method of calibrating an azimuthal inductive cross-coil or tilted coil instrument

An artificial neural network, ANN, and method of training the ANN for inversion of logging tool signals into well logs of formation parameters is disclosed. Properly selected synthetic models of earth formations are used to train the ANN. The models include Oklahoma and chirp type of formations. In each model parameter contrasts of from 10 to 1 to about 100 to 1 are included. Models including maximum and minimum parameter values spanning the operating range of the selected logging tool are included. Parameter contrasts at interfaces are limited to realistic values found in earth formations. The selected models are used to generate synthetic tool signals, which are then used as inputs to the ANN for training. When the ANN coefficients are properly adjusted to produce an output matching the original models, the ANN can be used for inversion of any real signals from the selected logging tool.

Processing well logging data with neural network

Measurements made by a multi-component induction logging tool are corrected for tool eccentricity in a deviated borehole. The eccentricity angle is determined from single frequency skin-effect corrected data and is then used to correct multifrequency data. Multifrequency focusing is then applied to the corrected multifrequency data. An inversion is then used to recover formation resistivity and relative dip and azimuth of the borehole.

Correction of multi-component measurements for tool eccentricity in deviated wells

Method and apparatus for making multi-component measurements in deviated wells

Measurements made with a multicomponent logging instrument when used in a substantially horizontal borehole in earth formations provide diagnostic of the direction of beds relative to the position of the borehole. When the logging instrument is conveyed on a drilling assembly, the drilling trajectory may be maintained to follow a predetermined trajectory or to maintain a desired distance from a boundary such as an oil-water contact.

Method and apparatus for the use of multicomponent induction tool for geosteering and formation resistivity data interpretation in horizontal wells

Measurements made with a multicomponent logging instrument when used in a substantially horizontal borehole in earth formations are diagnostic of the direction of beds relative to the position of the borehole. When the logging instrument is conveyed on a drilling assembly, the drilling trajectory may be maintained to follow a predetermined trajectory or to maintain a desired distance from a boundary such as an oil-water contact.

Cross-component measurements made at a plurality of toolface angles are processed to remove bias. The amplitude of the resulting sinusoid is used to estimate a distance to an interface in an earth formation.

Method for signal enhancement in azimuthal propagation resistivity while drilling

Measurements made by multiarray and multicomponent induction resistivity measurements in a borehole are used for determining the orientation and length of fractures in an earth formation when the fractures have a fluid with a resistivity different from that of the earth formation. The apparatus and method may also be used in anisotropic earth formations where the vertical and horizontal resistivities are different.

Determination of fracture orientation and length using multi-component and multi-array induction data

Data are acquired using multi-array logging tool in a borehole having an angle of inclination to a normal to the bedding plane of earth formations. The multi-array measurements are filtered using angle dependent filters to give a filtered curve corresponding to a target one of the multi-array measurements using angle dependent filters. Correlation coefficients are determined for a set of possible dip angles and a relative dip angle is estimated from the correlation coefficients. This dip angle estimate together with bed boundaries obtained from the multi-array measurements are used for inverting multi-component measurements alone or jointly with multi-array measurements to refine the relative dip angle interpretation and give horizontal and vertical formation resistivity.

Method for joint interpretation of multi-array induction and multi-component induction measurements with joint dip angle estimation

The invention is a method of determining horizontal and vertical resistivity in an anisotropic formation using a combination of orientable triaxial and array antennae conveyed downhole. Measurements are taken at various azimuthal angles about a measuring device at a given depth. Values at each azimuthal orientation can be fit to a curve to yield information on the surrounding formation. Multiple measurements at a given depth and azimuthal orientation can be weighted to obtain an average value. Values from the curve fitting process are used in subsequent inversion processing and reduce the uncertainty of the inversion processing result. Utilization of a three dimensional geometry enables a unique resolution of the orientation of the principle axis of anisotropy, and consequently of horizontal and vertical resistivity, and dip.

METHOD OF DETERMINING VERTICAL AND HORIZONTAL RESISTIVITY, AND RELATIVE DIP IN ANISOTROPIC EARTH FORMATIONS HAVING AN ARBITRARY ELECTRO-MAGNETIC ANTENNA COMBINATION AND ORIENTATION WITH ADDITIONAL ROTATION AND POSITION MEASUREMENTS

A coil array for high resolution induction logging comprises a transmitter, a first receiver set positioned at a first distance from the transmitter and a second receiver set positioned at a second distance from the transmitter, and the second receiver set includes at least one portion of the first receiver set. Also disclosed is a method for deriving an apparent conductivity log from at least one induction well log that comprises a plurality of depth samples, comprising the steps of raising each depth sample of the apparent conductivity signal to several predetermined powers to generate a plurality of powers of conductivity, convolving in depth the powers of conductivity with a plurality of filters, where each power has a distinct filter, and summing the results of all of the convolutions to produce a conductivity log that is substantially free from the effects of adjacent beds and the nonlinear effects of true conductivity. Also disclosed is an apparatus for measuring the resistivity of an earth formation penetrated by a borehole, comprising at least one transmitter that is energized by a time-varying, periodic voltage, at least one set of receivers generating a receiver voltage, an analog-to-digital converter that periodically samples the receiver voltage at a predetermined sampling rate and outputs a digitized voltage signal, a processor that receives the digitized voltage signal, and a set of N accumulators that collates and averages successive sets of N samples from the analog-to-digital converters to output a set of N averages.

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Houston, TX, United States of America

Gulamabbas A Merchant