Shell Offshore Inc.

Shell Oil Comapny

Anthony M Zibilich, Jr

Yoram Shoham

Garron J Chaisson

Mancel C Beam

A marine seismic cable section with stress members and internal wiring located within the cable section in a manner which reduces internal bending stresses upon the cable section when wound upon a storage reel. Stress members are at least near a horizontal plane passing through and at approximately equal distances from the center line of the cable section. Internal wiring is located in a vertical crisscrossing pattern down the length of the cable section. In one important embodiment, the cable section contains an elastomeric filler material to retain and support stress members, internal wiring and other internal components at their desired location and to prevent damage to internal wiring and components due to external stress when the cable section is wound on a cable reel. Stress relief sections are also provided to further reduce bending stress within the seismic cable section in other embodiments. Additionally embodiments to the cable section provide for adapting the cable section to a bottom cable which is laid on and couples with the sea floor to detect all three vectorial components of particle motion resulting from p- and s-waves and to detect p-waves with a hydrophone. Other embodiments provide for sealing and termination methods which are compatible with use of elastomer as a filler material for connecting detectors disposed within the cable section to internal wiring.

Marine seismic cable section assembly

A marine cable retrieval apparatus for retrieving marine seismic cable on board a ship which reduces longitudinal tension force on the cable at the cable storage reel when the cable storage reel (drum) is winding up the cable. Marine cable is subject to a tension force which can damage the marine cable when it is placed on a storage reel. The apparatus of this application reduces the tension on a portion of marine cable so that the portion can be retrieved upon a storage reel. The apparatus includes a collar attached to the marine cable and a cable retrievel tool which is placed around the marine cable. The cable retrieval tool has a biasing mechanism which will allow the tool to pass over the collar attached to the marine cable when it is moving away from the ship, but when it is moving toward the ship the biasing mechanism will engage the collar. The cable retrieval tool exerts an opposing force on the collar to the longitudinal tension force on marine cable trailing behind the collar. This reduces the longitudinal tension force on a portion of cable between the cable retrieval tool and the cable storage reel. The cable storage reel can then wind up the portion of cable with a reduced longitudinal tension on the cable at the cable storage reel.

Seismic cable retrieval apparatus and method

A marine cable deployment apparatus for deploying marine seismic cable from a ship which reduces tension force on the cable at the cable storage reel when the cable storage reel (drum) is winding out the cable. Marine cable is subject to a longitudinal tension force which can damage the marine cable when it is deployed from a storage reel. The apparatus of this application reduces the longitudinal tension force on a portion of marine cable so that the portion of cable can be deployed from a storage reel. The apparatus includes a collar attached to the marine cable and a cable deployment tool which is placed around the marine cable. The cable deployment tool has dogs which engage the collar and a locking ring which holds the dogs in place. The cable is deployed with the deployment tool accompanying the deployed cable. A line between the deployment tool and the ship provides an opposing force to the longitudinal tension force on the cable trailing behind the collar. After the portion of cable is deployed the opposing force on the cable retrieval tool is reduced to a point that the deployed portion of cable assumes the longitudinal tension force on the cable trailing behind the collar. The tension on the line is released. The locking ring slides back on the deployment tool releasing the dogs from the collar. The deployment tool is pulled back along the cable to the ship to attach to the next portion of cable to be deployed.

Seismic cable deployment apparatus

A geophone assembly for use in a marine seismic cable to detect converted shear waves reflected from the strata in response to a compressional wave generated in the body of water associated with the strata. The geophone assembly comprises a cylindrical mount that has a central aperture and a geophone positioned in the central aperture. The mount has a plurality of additional apertures that are sized and positioned to accommodate the plurality of stress members in the cable, and the mount is sized and made of a material so that the weight of the mount is sufficient to cause at least the portion of the cable jacket that is adjacent the mount to contact the seafloor.

Marine cable geophone assembly

A marine cable for detecting converted shear waves reflected from the strata beneath a body of water in response to a compressional wave generated in the body of water. The cable comprises a jacket, a mount attached to the stress member, a geophone positioned in the mount, a first weight assembly attached to the stress member and positioned proximate a first end of the mount and a second weight assembly positioned proximate a second end of the mount. The mount is sized and made of a material so that its weight is sufficient to cause at least the portion of the cable jacket that is adjacent the mount to contact the seafloor. The first and second weight assemblies are sized and made of material so that their respective weights cause at least the portion of the cable jacket that is adjacent to the respective weight assemblies to contact the seafloor.

Growing community of inventors

Mandeville, LA, United States of America

Anthony M Zibilich, Jr