Baker Hughes Corporation

Halliburton Energy Services, Inc.

Western Atlas International, Inc.

Core Health & Fitness, LLC

Land America Health & Fitness Co. Ltd.

David R Beard

Arcady Reiderman

Songhua Chen

Gregory Boris Itskovich

Leonty Abraham Tabarovsky

Burkay Donderici

Robert A Lester

Baris Guner

Carl M Edwards

Lilong Li

Hans-Martin Maurer

Victor Cornejo

Thomas Kruspe

Michael Rabinovich

Tsili Wang

Daniel T Georgi

Randy Gold

Edward Harrigan

Michael D Morgan

Martin Blanz

Alexandre N Bespalov

Sheng Fang

Kurt M Strack

Holger Thern

Gary Wayne Kainer

Junwen Dai

Randolph Scott Coles

Fei Le

Jiaqi Xiao

Zinovy B Krugliak

Bill H Corley

Deo Magakat

Muralidhar Seshadri

Ingo M Geldmacher

Alberto G Mezzatesta

Steve Neill

Carlos A Yanzig

Qiang Zhou

Chang S Shin

Milton E Cram

Yuesheng Cheng

Arcady Reidermann

Rashid W Khokar

Carlos Yansig

Michael A Jervis

William D Johnson

Kevin Corbalis

A method and a system for tuning a pad. The method may comprise disposing a downhole tool into a borehole, configuring the pad in a first configuration, taking a first measurement of the formation in the first configuration, configuring the pad in a second configuration, taking a second measurement of the formation in the second configuration, determining a tuning coefficient to reduce a tool body effect in the first measurement and the second measurement, computing a first weighted measurement from the tuning coefficient and the first measurement, computing a second weighted measurement from the tuning coefficient and the second measurement, and computing a tuned impedance from a ratio of the first weighted measurement and the second weighted measurement. A system for determining a formation boundary may comprise a downhole tool, an arm, and a pad. The system may further comprise a conveyance and an information handling system.

Software tuning of borehole imagers

A method and system for estimating a resistivity of a formation. A method for estimating a resistivity of a formation may comprise disposing a downhole tool into a borehole, wherein the downhole tool comprises a pad, an injector electrode, and a return electrode, injecting a current signal into the formation from the injector electrode, measuring a voltage signal between the injector electrode and the return electrode; and determining a formation resistivity and a formation dielectric constant from at least one of the voltage signal, at least one property of the downhole tool, and at least one property of the borehole. A system for estimating a resistivity of a formation may comprise a downhole tool. The downhole tool may comprise a pad, wherein the pad comprises an injector electrode and a return electrode. The system may further comprise a conveyance for disposing the downhole tool in a borehole and an information handling system.

Method to estimate formation resistivity

A downhole tool may comprise a tool body that is a structural support for the downhole tool, an upper arm attached at one end to the tool body, a pad attached at an opposite end of the upper arm, a lower arm attached at one end to a sliding block and attached to the pad at an opposite end of the lower arm, and a passive arm connected to the lower arm and the tool body. A method may comprise disposing a downhole tool into a borehole, applying a force to a passive arm, applying a second force from the passive arm to the lower arm in response to the force applied to the passive arm, and moving the lower arm and the passive arm in a longitudinal direction along an axis of the downhole tool.

Passive arm for bi-directional well logging instrument

A method and system for interspersing different wait times in trainlet and partial recovery sequences is provided. The method includes introducing a nuclear magnetic resonance (NMR) tool into a wellbore penetrating a subterranean formation. The method also includes applying an NMR pulse sequence to the subterranean formation using the NMR tool, in which the NMR pulse sequence includes at least two different wait times interspersed between successive sequences of radio frequency (RF) pulses. The method also includes measuring one or more echo signals corresponding to a substance in the subterranean formation based on the applied NMR pulse sequence. The method also includes determining a distribution of a characteristic of the substance based on the measured one or more echo signals.

Interspersing different wait times in trainlet and partial recovery sequences

A downhole tool, comprising: a tool mandrel; a pad comprising a transmitter operable to transmit an electric current into a formation and a receiver operable to receive at least a portion of the electric current from transmitter; an extension from the tool mandrel that couples pad to tool mandrel; and a signal filter positioned in the downhole tool to suppress passage of mandrel leakage current that passes through tool mandrel to pad. A method of resistivity imaging, comprising: disposing a downhole tool into borehole; transmitting a current into formation surrounding the borehole with a transmitter that is extended from tool mandrel of the downhole tool towards borehole wall; and recording at least a portion of the current that returns to receiver of downhole tool, wherein a signal filter suppress passages of mandrel leakage current that passes through the tool mandrel to a pad on which the transmitter is disposed.

Electromagnetic insulating component used in well logging tool pad

This disclosure relates generally to downhole tools and, more particularly, embodiments related to incorporation of a pumpdown relief valve into a downhole tool that is responsive to changes in differential fluid pressure along a downhole tool. Disclosed is a system for pumpdown regulation in a wellbore. The system may include a downhole tool having a tool body with a tool head that is attachable to a line, the line being attached to a point at a surface of the wellbore. The system may further include a pumpdown relief valve coupled to the tool body that is operable to allow fluid to bypass the downhole tool in direct response to a differential fluid pressure across a length of the downhole tool.

Pumpdown regulator

A logging instrument for estimating a property of a formation is provided. The instrument includes a magnet to generate a magnetic field. The instrument also includes pulse sequencer circuitry that supplies radio frequency (RF) signals. The instrument additionally includes an antenna system configured to transmit the RF signals and to obtain nuclear magnetic resonance (NMR) measurements of the formation in response to the transmitted RF signals. In one aspect, the logging tool contains a temperature sensor configured to obtain temperature measurements of the magnet. The instrument additionally includes a control unit communicatively coupled to the temperature sensor, the antenna system and the pulse sequencer circuitry and configured to receive the temperature measurements and selectively adjust operating parameters of the pulse sequencer circuitry based on the received temperature measurements in order to maintain optimal intensity of the magnetic field.

RF flip angle adjustment in a downhole NMR tool

A nuclear magnetic resonance logging tool is provided. The tool includes a flexible or semi-flexible circuit board, at least one capacitor mounted on board, and a controller programmed to apply sequential pulses to the at least one capacitor of the tool with a spacing of less than 600 &#x3bc;s between adjacent pulses. Ring down time induced by the at least one capacitor in response to pulses is less than about 200 &#x3bc;s.

Downhole detector with reduced ringing

This disclosure relates to apparatuses and methods for reducing current leakage between a measure electrode and a logging tool body during borehole investigations in an earth formation involving electric current and non-conductive drilling fluid. The apparatus may include one or more transmitters disposed on a pad body, configured to inject an electric current into the earth formation, and coupled to the mandrel and one or more measure electrodes. The measure electrodes may be configured to receive current from the formation and coupled to a back plate of the pad body. The apparatus may be configured to maintain a selected ratio between pad body to logging tool body impedance and transmitters to logging tool body impedance sufficient to reduce current leakage between the earth formation and the logging tool body. The transmitter/mandrel and measure electrode/back plate may be electrically isolated from one another. The method may include using the apparatus.

Electrical imager operating in oil-based mud and low resistive formation

An apparatus and method for estimating a parameter of interest of an earth formation. An apparatus includes an elongated support member; a primary transmitter on the elongated support member; and a receiver toroid on the elongated support member, the receiver toroid being positioned transversely on the elongated support member and including a single coil antenna. Methods include positioning a logging tool in a borehole in the earth formation; using a transverse receiver toroid on an elongated support member on the logging tool, wherein the transverse receiver toroid includes a single coil antenna; and producing a signal responsive to an electrical signal produced by a primary transmitter.

Estimating a parameter of interest with transverse receiver toroid

An apparatus and method for estimating a parameter of interest of an earth formation, particularly relating to borehole logging methods and apparatuses for estimating electrical resistivity properties at multiple depths of investigation. The apparatus may include two or more transmitters for introducing electrical current to the earth formation. The apparatus may include a controller configured to deliver an electrical signal to the two or more transmitters either simultaneously or sequentially. The controller may deliver an electrical signal to two or more transmitters at the same frequency for estimating depth of investigation. The apparatus may include one or more receivers responsive to electric signals from the earth formation at one or more frequencies to provide data from one or more depths of investigation. The method may include steps for using the apparatus to obtain data that may be used to estimate the parameter of interest.

Multiple depths of investigation using two transmitters

In aspects, an apparatus for use in a wellbore for determining a property of an earth formation is provided. The apparatus, in one embodiment, may include a tool body including a transmitter configured to induce electromagnetic waves in an earth formation, a receiver configured to provide signals responsive to the induced electromagnetic waves, a conductive member between the transmitter and the receiver extending radially from the tool body and configured to reduce propagation of eddy currents between the transmitter and the receiver when the tool body is in a wellbore and a processor configured to process the signals provided by the receiver to determine the property of the earth formation.

Apparatus and method for reducing effects of eccentricity in induction tools

An apparatus for imaging a subsurface material traversed by a borehole, the apparatus including an imaging pad deployed by a logging instrument, the pad including a plurality of measuring sets, each measuring set including a first current injector electrode, a second current injector electrode, a pair of sensor electrodes disposed between the first current injector electrode and the second current injector electrode, and an output for coupling to an electronics unit adapted for producing the imaging of the subsurface material.

Apparatus and method for imaging subsurface materials using a pad having a plurality of electrode sets

A magnet assembly for measuring properties of a formation from a borehole, the magnet assembly including a first device and a second device, each device adapted for insertion into the borehole, the first device producing a first magnetic field, the second device producing a second magnetic field; wherein the second magnetic field is configurable for one of reinforcing and reducing the first magnetic field; and wherein the first device comprises a permanent magnet and the second device comprises at least one of one of a switchable magnet and switching windings.

Configurable magnet assembly for using in NMR well logging instrument

The quality factor of a NMR-antenna depends upon mud conductivity, formation resistivity and the borehole size. The Q of the antenna is measured. From measurement of one of formation conductivity or borehole size, the other can be determined.

Method and apparatus for formation evaluation and borehole size determination

Growing community of inventors

Houston, TX, United States of America

David R Beard