Deep sea well drilling structure

Claim 1

An underwater well head encasement structure for mounting below the water surface and on the ocean bottom by use of a floating work vessel comprising: a tubular caisson having a lower end adjacent the ocean floor and having an upper end at a depth below the water surface within which a diver serviced by said vessel can operate; a base at the lower end of said tubular caisson; lateral supports for said tubular caisson comprising a plurality of diagonal braces having upper ends in engagement with the wall of the caisson intermediate upper and lower ends, lower ends of said braces being secured in the ocean bottom; a housing mounted on the upper end of the caisson including a side wall structure forming a chamber over said upper end, a bottom wall closing the lower side of said housing and extending over the upper end of said caisson, a plurality of drill guides extending from said bottom wall to said base, said wall structure having an upper perimetral rim forming an opening at least as large as the interior of said caisson to enable the drilling of wells through said drill guides and the setting of well casings in said wells; and a substantially annular closure for said housing having a supporting edge on the lower side in removable sealed position on said rim.