Unique equipment used to build Cognac line

According to C.G. Langner and H.M. Wilkinson of Shell Oil Co. at the Offshore Technology Conference (Houston 1980), the 12 inch Cognac pipeline from Mississippi Canyon Block 194 in the Gulf of Mexico to Shell's production facilities on the Mississippi River Delta reaches a water depth of 1,020 feet, the deepest operating oil pipeline in the world; began operation 9/19/79; moves two-phase gas/oil production from the Cognac platform to shore at a gas-oil ratio of about 700-800 std cu ft/bbl at 3,000-30,000 bbl/day throughout; and is probably the largest diameter and deepest J-tube riser installed to date. Devices used during installation included a subsea insulating coupling and 120 zinc anode bracelets for cathodic protection; unmanned submersibles for installing messenger wire through the J-tube; a 400,000 pound tension cable pulling machine, with 2.5 inch wire cable and special pipeline pull head, which pulled the riser through the J-tube conduit; and an electronic navigation system for the lay barge. In 1981, a second line, probably a 16 inch gas line, will be laid, and the present line will carry single-phase oil at 50,000 bbl/day max throughput. The construction of the Cognac line is discussed.