Santa Fe International Corporation

Gerald L Johnson

Peter W Braddick

Arun Bhalaik

Darryl S Brittin

Daniel G Whyte

Almeron J Field

A marine operations structure for use in arctic seas having steel/concrete composite ice walls positioned to permit multi-year ice ridges to be broken up with lower vertical forces imposed on the structure than heretofore possible. The structure provides for simultaneous contacting and fracturing of both surface ice floe and multi-year ice ridges by proportioning of the ratio of the annular dimension of a first sloped surface to the radius of the structure within the range of about from 0.15 to 0.30. The structure is fabricated by modular construction techniques which lowers total construction costs. The structure is in the form of a sixteen-sided polygonal sloped walled marine structure with internal ballast tanks for providing gravity founding of the structure on the sea floor. Modular drilling equipment is provided for and supported by the structure for use through two rectangular shaped moon pools extending vertical throughout the central core of the structure. The process for simultaneously contacting and fracturing surface ice floes and ice pressure ridges is set forth along with the processes of installing and deballasting and relocating the structure. Also the process of fabricating the marine operations structure is set forth.

Mobile marine operations structure

A mobile sea barge having a unitary lower hull which has sufficient buoyancy to float the entire barge, an upper hull spaced from the lower hull by a single, centrally-positioned, vertical member, and a movable stabilizing hull arranged about the central support member for controlled movement between the upper and lower hulls is provided. Controlled movement of the stabilizing hull permits the operational modes of submerging and emerging of the lower hull into or from a bottom-founded gravity-forced mode from which drilling operations can be carried out. In the bottom-founded mode on the sea floor the barge functions as a gravity platform. Movement of the stabilizing hull is provided by a plurality of jacking legs and jacking units which constitute the control devices. The barge can be quickly switched between the surface-floating and the gravity-forced, bottom-founded modes. Controlled vertical descent to the sea floor is provided by the static stability of the stabilizing hull. The jacking legs, which are preferably four in number, are under compressive force during the submerging and the emerging modes of operation. The vertically movable stabilizing hull may be used to fail ice features by exerting downward pressure on the ice between the upper and lower hulls and by positioning the stabilizing hull adjacent the waterline for engaging ice floes to fail the floes in flexure.

Mobile sea barge and plateform

A mobile sea barge having a unitary lower hull which has sufficient buoyancy to float the entire barge, an upper hull spaced from the lower hull by a single, centrally-positioned, vertical member, and a movable stabilizing hull arranged about the central support member for controlled movement between the upper and lower hulls is provided. Controlled movement of the stabilizing hull permits the operational modes of submerging and emerging of the lower hull into or from a bottom-founded gravity-forced mode from which drilling operations can be carried out. In the bottom-founded mode on the sea floor the barge functions as a gravity platform. Movement of the stabilizing hull is provided by a plurality of jacking legs and jacking units which constitute the control devices. The barge can be quickly switched between the surface-floating and the gravity-forced, bottom-founded modes. Controlled vertical descent to the sea floor is provided by the static stability of the stabilizing hull. The jacking legs, which are preferably four in number, are under compressive force during the submerging and the emerging modes of operation.

Growing community of inventors

Orange, CA, United States of America

Gerald L Johnson