GB896960A - Marine drilling platform support structure - Google Patents

Abstract

896,960. Marine drilling platform supports. CALIFORNIA RESEARCH CORPORATION. Sept. 21, 1960 [Oct. 1, 1959], No. 32430/60. Class 68(2). A drilling platform 20 mounted on a box girder 204 is supported on a structure which can be assembled as a unit on land and floated in a horizontal position to an offshore drilling site where it can be rotated to a vertical position and set on the sea bottom, comprises four elongated column members secured rigidly together in parallel spaced relationship by cross bracing and disposed in a substantially rectangular configuration with respect to a plane positioned transversely to the longitudinal axis of said column members, a first two adjacent principal column members 48, 50 of said four column members constructed as elongated watertight pontoons of sufficient buoyancy to float the structure on the water in a horizontal position with the second two 52, 54 of said four column members positioned above the first two, partitions in each of the first two forming separate watertight chambers 92, 94, 96, 98 positioned sequentially along each column member 48, 50, means for controllably admitting water and air into each chamber separately and means for exhausting said water and air therefrom, the second column members 52, 54 constructed with members 56, 58 of a smaller transverse dimension and of less weight than the first two column members and a controllably buoyant section 60, 62 of enlarged transverse dimension forming the bottom portion of each of the second column members, a partition in each buoyant section forming separate water tight chambers 124, 126 therein, means for controllably admitting water and air into each chamber separately of each other and means for exhausting water and air therefrom. The column members 48, 50 have cylindrical shells 64 housing tubular guide members 66, 68. The sections 60, 62 of the other column members contain guide members 100. The members 66, 68, 100 provide guides for drilling for tubular piling 232 through which oil wells 262 are drilled by drill bit 266.