Schlumberger Technology Corporation

Westerngeco L.l.p.

Erwann Lemenager

Matthe Contant

Yves G Mathieu

Guillaume Millot

Dean M Homan

Herve Ohmer

Klaus B Huber

David L Smith

Christian Chouzenoux

Martin G Luling

Randolph J Sheffield

Sylvain Chambon

James G Filas

Gaelle Jannin

Sameer Bhoite

Jon Brunetti

Jaroslav Dobos

Juergen Zach

Huicheng Pan

Richard Voon Choong Wong

Mathias Contant

Asif Khaleel

Carl Daniel Cooper

Michael Bladon

An apparatus for detecting an electromagnetic signal originating in a wellbore includes an antenna comprising a pair of spaced apart electrodes in the ground spaced apart by a first distance having a midpoint at a second distance from the wellbore. The system includes at least one of a shielded electrical cable connecting each electrode to an input of a detector circuit, wherein the shielding is connected to produce common mode noise rejection; b) a second spaced apart electrode pair antenna spaced apart by one half the first distance and having a midpoint spaced &#x221a;2/2 times the second distance from the surface of the wellbore, c) a second electrode pair antenna having a common midpoint with and being orthogonal to the at least one electric dipole antenna; and d) wherein the at least one electric dipole antenna is disposed in a second wellbore, the second wellbore having substantially no electrically conductive pipe therein.

Electric dipole surface antenna configurations for electromagnetic wellbore instrument telemetry

An electromagnetic (EM) telemetry system includes an EM transmitter configured to transmit EM signals downhole and multiple sensors each configured to communicate with the EM transmitter and with another of the multiple sensors. Each sensor is placed a distance from another sensor along a length of a wellbore in the EM telemetry system. The EM telemetry system also includes a processor configured to select two or more sensors of the multiple sensors based on a signal to noise ratio (SNR) of an EM signal received from the two or more selected sensors, a depth of the EM transmitter, or both.

Downhole electromagnetic sensing techniques

A method for conducting survey measurements in a ranging operation between a first well and a second well include generating an electromagnetic field in a downhole location in the first well and scanning for the electromagnetic field in a downhole location in the second well. When at least one characteristic of the electromagnetic field is detected, the method includes automatically initiating survey measurements for a ranging operation without receiving a downlink command from surface.

Downhole electromagnetic communications between two wells

A data retrieval device for communicating between a downhole location within a wellbore () and a surface location () in which a downhole to surface telemetry system is installed and adapted to communicate between a first telemetry module and a second telemetry module with the second telemetry module () positioned downhole and connected to a string () positioned within the wellbore (). The data retrieval device is provided with a housing adapted to be positioned inside the string; a communication device supported by the housing; a connection port positioned on the housing and adapted to be connected to a line; and an electronic module supported by the housing. The electronic module is in communication with the communication device and is adapted to store and use at least an identification parameter of the first telemetry module to intercept a signal transmission addressed to the first telemetry module from the second telemetry module () via the communication device.

Data retrieval device for downhole to surface telemetry systems

A method and system are presented for transmitting data along tubing in a borehole, comprising generating an acoustic signal using a transmitter at a first location on the tubing, and receiving the acoustic signal at a receiver at a second location on the tubing. The method and system further comprise: (i) generating the acoustic signal at the transmitter at a first frequency and bit rate; (ii) receiving the acoustic signal at the first frequency at the receiver and attempting to synchronize the receiver at the first frequency, and (iiia) if the synchronization is successful, continuing to transmit the acoustic signal so as to pass the data from the transmitter to the receiver; or (iiib) if the synchronization is unsuccessful, adjusting the frequency and/or bit rate of the signal and repeating steps (i)-(iii) on the basis of the adjusted signal.

Transmitter and receiver synchronization for wireless telemetry systems

Techniques involve determining the conductivity profile of a formation from a well between a surface location and a borehole location. The method involves placing a first sensor at the surface location, a second sensor located at the borehole location, obtaining a first signal by detecting Schumann resonances from the electric field occurring at the first location, obtaining a second signal by detecting Schumann resonances from the electric field occurring at the second location with the second sensor; and combining the first and the second signal to determine the conductivity profile of the formation between the first location and the second location.

Method and apparatus for transmitting or receiving information between a downhole equipment and surface

A downhole electromagnetic telemetry unit for use with a tubing string () includes an insulated electrically conductive member () and a processing unit (). The insulated electrically conductive member () is electrically coupled to the tubing string () at an upper measuring point () and a lower measuring point (). The processing unit () is configured to process a voltage difference measured between the upper measuring point () and the lower measuring point () across the insulated electrically conductive member () and to derive therefrom a signal transmitted from a surface location ().

Apparatus for receiving and transmitting signals in electromagnetic telemetry system used in a wellbore

An EM antenna for location on a pipe () surrounded by a casing (). The antenna has a power source () for injecting a current across a first insulated section () of the pipe () and an electrode () for conducting the current from the pipe () to the casing (). There is also a second insulated section () of the pipe arranged to operate together with the electrode () and first insulated section () for directing a path flow of the current. Such antennas are described both in relation to repeater arrangements as well as land and sea applications.

Downhole telemetry system

A subsea communication system includes addressable nodes in a wellbore and addressable nodes on a floor, where the nodes in the wellbore and on the floor are able to communicate wirelessly with each other, such as through a formation.

Wireless communications associated with a wellbore

A method is provided for accurately determining the physical location of a deployed seismic geophone used in seismic investigations by using a portable navigational satellite receiver to obtain a set of navigational satellite measurements providing the position of the deployed geophone at the time of deployment of the geophone into the earth. A method is provided for automatically and accurately identifying and determining the physical location of a deployed geophone used in seismic investigations by using one or more portable navigational satellite receivers and an automatic geophone identification and tracking system at the time of geophone deployment.

Growing community of inventors

Calgary, Canada

Erwann Lemenager