Schlumberger Technology Corporation

Tianxia Zhao

Brian Oliver Clark

Aria Abubakar

Raphael Gadot

Gong Li Wang

Keli Sun

Alexander Trushin

Matthew Cannon

A downhole tool includes a chassis having a bore formed axially-therethrough. An antenna is positioned radially-outward from the chassis. A collar is positioned radially-outward from the antenna. A window is defined radially-through the collar. An insert is positioned in the window. The insert is made at least partially of a ceramic material.

Antenna for a logging-while-drilling tool

Identifying the dielectric constant and/or the electrical resistivity of part of a geological formation may reveal useful characteristics of the geological formation. This disclosure provides methods, systems, and machine-readable media to determine dielectric constant or electrical resistivity, or both, using contraction mapping. Specifically, contraction mapping may be used with a function of wavenumber k to iteratively solve for values of dielectric constant and electrical resistivity until convergence is achieved. This may allow for convergence to a solution without computing partial derivatives and/or with fewer iterations than previous techniques.

Systems and methods for determining dielectric constant or resistivity from electromagnetic propagation measurement using contraction mapping

An inductive coupler apparatus have a first inductive coupler with a first magnetic center shaft having a recessed portion, a first outer magnetic layer disposed around the first magnetic center shaft, and a first coil disposed around the first magnetic center shaft and disposed within the first outer magnetic layer and a second inductive coupler with a second magnetic center shaft having a recessed portion, a second outer magnetic layer disposed around the second magnetic center shaft, and a second coil disposed around the second magnetic center shaft and disposed within the second outer magnetic layer. When the first and second inductive couplers are in the coupled position the inductive couplers can provide for the transmission of power and/or communication between downhole tools in a bottom hole assembly.

Inductive coupler

Growing community of inventors

Stafford, TX, United States of America

Tianxia Zhao