Schlumberger Technology Corporation

Alexandre G E Kosmala

Michael R Johnson

Ronald E Pringle

Joseph P Varkey

Christophe M Rayssiguier

David L Malone

John A Booker

Chistophe M Rayssiguier

A system for protecting the transmission of signals from and/or to a tool in a high pressure environment. The system includes a tool connected to a signal transmission line, such as an electrical cable or optical fiber. The signal transmission line is surrounded by a protective tube that is connected to the tool by a connector having a hollow chamber in communication with the interior of the tube. A fluid, such as a dielectric liquid, is disposed within the connector and the tubing at a pressure higher than the environmental pressure. In the event of a leak at, for instance, the connector, the high pressure fluid flows outwardly rather than allowing the inflow of deleterious fluid from the environment.

Pressurized system for protecting signal transfer capability at a subsurface location

A downhole string includes a liner and devices positioned outside the liner. One or more control lines extend from the liner devices along the exterior of the liner to one or more connectors that provide connection points inside the liner. The one or more connectors may include electrical connectors (e.g., direct contact connectors), inductive connectors (e.g., inductive couplers), optical connectors (e.g., fiber optic connectors), and hydraulic connectors. The one or more control lines may be electrical lines, fiber optic lines, or hydraulic lines. The downhole string may also be used with a cement protector during cementing operations to protect both the inside of the liner as well as the one or more connectors attached to the liner. The cement protector includes a sleeve that isolates cement from the inside of the liner during a cementing operation so that a liner wiper plug is not needed. The cement protector is engageable to a pulling tool that is attached to a running tool. The running tool in turn is connected to a pipe through which a cement slurry can be pumped. The cement slurry pumped through the inner bore of the pipe enters the sleeve of the cement protector. One or more ports are provided in the cement protector sleeve to enable communication of the cement slurry to an annulus region between the outer wall of the liner and the inner wall of the wellbore. If the apparatus and method is used with a casing, then a running tool may be omitted.

Communicating with devices positioned outside a liner in a wellbore

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Houston, TX, United States of America

Alexandre G E Kosmala