Schlumberger Technology Corporation

University of Houston System

Iowa State University Research Foundation, Inc.

Desheng Zhang

Brian Oliver Clark

Jean P Seydoux

Michael Andrew Montgomery

Qiming Li

Julius Kusuma

Ioannis A Kakadiaris

David K Hoffman

Lili Zhong

Gemunu H Gunaratne

Haixiang Wang

Yi Zhang

Zhuoer Shi

Kent David Harms

Qingyan He

Donald J Kouri

Xueyuan Tang

Guowei W Wei

Zheng Bao Xi'an

G W Wei

Zheng Bao

Tang Xueyan

Donald K Kouri

Kong Hauw Sarwa Bakti Tan

Daniel Fernandez

Qing Zhang

Mark Arnold

A method for calibrating an electromagnetic measurement tool includes deploying a test loop about a first antenna in the electromagnetic measurement tool and electromagnetically coupling the test loop and the first antenna and measuring a first voltage. The test loop is then deploying about a second antenna in the electromagnetic measurement tool and electromagnetic ally coupling the test loop and the second antenna and measuring a second voltage. A ratio of the first voltage to the second voltages is computed that can be used to calibrate the first antenna with respect to the second antenna.

Antenna calibration in an EM logging tool

A system and a method use dual telemetry for tools located in a wellbore. A first telemetry system and a second telemetry system coordinate communication with the tools. Both the first telemetry system and the second telemetry system may transmit data regarding the tools and/or drilling conditions from the tools to a surface location simultaneously. The first telemetry system or the second telemetry system may communicate with the surface location if communication using the other telemetry system is interrupted. The first telemetry system and the second telemetry system may have a master/slave relationship so that data requests from a specific telemetry system do not interfere with data requests from the other telemetry system.

System and method for using dual telemetry

The present disclosure relates to a method to determine a clock signal when separate clocks are used. In one embodiment, a disciplined clock system comprising an update subsystem and a synthesis subsystem is provided. A first clock phase estimate is provided to the update subsystem and used, along with the update subsystem, to determine a frequency offset estimate and a phase offset estimate. The clock signal is determining using the frequency offset estimate, the phase offset estimate, and the synthesis subsystem. Alternatively, two clocks can be synchronized by generating a signal associated with a first clock; modulating the signal; transmitting the modulated signal; receiving the modulated signal by a receiver associated with a second clock; correlating the received signal; determining the time of arrival of the received signal; determining the time difference between the two clocks; and synchronizing the two clocks.

Synchronization between devices

A method for padding, filtering, denoising, image enhancing and increased time-frequency acquisition is described for digitized data of a data set is described where unknown data is estimated using real data by adding unknown data points in a manner that the padding routine can estimate the interior data set including known and unknown data to a given accuracy on the known data points. The method also provides filtering using non-interpolating, well-tempered distributed approximating functional (NIDAF)-low-band-pass filters. The method also provides for symmetric and/or anti-symmetric extension of the data set so that the data set may be better refined and can be filtered by Fourier and other type of low frequency or harmonic filters.

Methods for performing DAF data filtering and padding

A method for padding, filtering, denoising, image enhancing and increased time-frequency acquisition is described for digitized data of a data set where unknown data is estimated using real data by adding unknown data points in a manner that the padding routine can estimate the interior data set including known and unknown data to a given accuracy on the known data points. The method also provides filtering using non-interpolating, well-tempered distributed approximating functional (NIDAF)-low-band-pass filters. The method also provides for symmetric and/or anti-symmetric extension of the data set so that the data set may be better refined and can be filtered by Fourier and other type of low frequency or harmonic filters.

Growing community of inventors

Missouri City, TX, United States of America

Desheng Zhang