Exxon Production Research Company

Motorola Corporation

John M Bednar

Clifford W Petersen

James M Henderson

Dale V Johnson

Terry V Jones

Daniel G Taft

Jere A Noerager

Edwin J Hocker, Jr

Daniel P Postler

David H Gauger

A choke arrangement useful in subsea completions in a subsea tree cap. The subsea choke arrangement allows for refitting of existing subsea tree arrangements to allow for the installation of a choke arrangement that can be easily maintained and removed. Also, a choke arrangement is shown that allows the choke to be isolated after failure which permits continued production of the well until repair or replacement operations can be implemented.

Subsea tree cap well choke system

Well apparatus for use in injecting corrosion inhibitor into the annulus between casing and tubing strings below an injection/packer assembly positioned in such annulus which includes an annular gas trap positioned below the injection/packer assembly. The annular gas trap comprises a plurality of individual gas traps. Each individual gas trap comprises a series of S-shaped conduits and includes one passageway open to the annulus above the gas trap and another passageway open to the annulus below the gas trap and a third passageway connecting those two passageways. A check valve may be positioned in each individual gas trap to prevent flow of fluids upwardly through the gas trap into the annulus above the gas trap and a seal may be provided on the gas trap to engage a polished bore receptacle formed on the casing string to seal off the space between the casing string and the annular gas trap.

Annular gas trap

This invention relates to a self-contained circulation sub which may be operated upon control from the surface. It may be in the shape of a short section of drill collar and utilizes a sleeve valve to cover the circulation ports. Upon reception of an acoustic signal from the surface, a control valve directs fluid from the pipe bore onto a pressure face on the sleeve valve. The sleeve valve then moves down and exposes the circulation ports thereby allowing drilling fluids to pass from its interior to its exterior.

Acoustically controlled electro-mechanical circulation sub

An acoustically operated downhole blowout preventer using a specially configured sleeve valve to inflate a resilient packer for shutting the wellbore annulus.

Acoustically actuated downhole blowout preventer

A portable, electrohydraulic, acoustic transmitter releasably attaches to a solid medium such as a drill string to generate essentially longitudinal, acoustic signals in the medium. The signals are frequency modulated so that encoded messages may be transmitted between a surface and subsurface location to activate downhole equipment.

Acoustic transmitter and method to produce essentially longitudinal,

A tensioner system is disclosed for applying tension to a riser pipe extending between a floating vessel and the sea bottom. The tensioner comprises a guide means fixed onto the floating vessel for restraining guide members from substantial lateral movement relative to the vessel while permitting relative vertical motion of the guide members, means on the vessel for applying vertical tension to the guide members and suitable means for connecting the guide members to the riser such that the vertical tension applied to the guide members is substantially the same as the vertical tension applied to the riser.

Growing community of inventors

Houston, TX, United States of America

John M Bednar