Apparatus for underwater drilling and well completion

Claim 1

FOR USE IN AN UNDERWATER WELL INSTALLATION, A DRILL PIPE CONDUCTOR TUBE AND HYDRAULIC CONTROL CLUSTER, COMPRISING A PLURALITY OF SECTIONS, EACH SECTION HAVING A CENTRAL RELATIVELY LARGE DIAMETER TUBE HAVING RADIAL FLANGES ADJACENT EACH OF ITS ENDS, EACH OF SAID FLANGES HAVING A PLURALITY OF AXIALLY EXTENDING BORES FORMED THEREIN AT POINTS SPACED CIRCUMFERENTIALLY ABOUT THE AXIS OF SAID LARGE DIAMETER TUBE, A PLURALITY OF PIPES RIGIDLY SECURED TO SAID LARGE DIAMETER TUBE, EACH OF THE OPPOSITE ENDS OF EACH OF SAID PIPES BEING RECEIVED WITHIN ONE OF SAID BORES IN ONE OF SAID FLANGES AND BEING FIXED TO SAID FLANGE, EACH OF SAID BORES AND THE BORE OF SAID CENTRAL TUBE BEING COUNTERBORED, A PLURALITY OF COUPLING NIPPLES EACH RECEIVED HALF IN A COUNTERBORE IN ONE SECTION AND HALF IN THE ASSOCIATED COUNTERBORE OF THE NEXT ADJACENT SECTION, AND MEANS FOR CONNECTING ONE FLANGE OF ONE SECTION TO ONE FLANGE OF THE NEXT ADJACENT SECTION.