In April 1979 Texaco Canada Resources Ltd. spudded a well approximately 200 miles offshore Newfoundland. The well, named Texaco Shell et al Blue H-28. was located in a water depth of 4876 feet. The depth established a new world record in deepwater drilling for the purpose of conventional hydrocarbon exploration.
The venture was the results of a farm-in by Texaco and four other companies to earn an interest in acreage held jointly by Shell Canada Resources Limited and Shell Explorer Limited. The four other companies involved, were Petro Canada Exploration Inc. Hudson's Bay Oil and Gas Company Limited, Home Oil Company Limited and Dome Petroleum Limited. The acreage being drilled on was known as the Gander Block and included approximately 5.5 million acres located in water depths ranging from approximately 1500 to 7000 feet. H-28 was the first well to be drilled on the block which, according to seismic information, contained a number of large geological structures. H-28 was to penetrate one of the larger structures to determine if the structure vas, in fact, a hydrocarbon bearing reservoir.
The actual drilling operation was me elimination of more than a year of planning and preparation necessary to acquire a suitable drilling unit. support vessels, tubulars and an extensive list of equipment. Selection of the drilling vessel was of primary concern since the success of the operationdepended on the ability of a vessel to operate in an unprecedented water depth.
The drilling vessel required to drill Blue H-28 was of a very specialized nature since few rigs had operated in a water depth that even approached 5000 feet. Bids for a suitable drilling vessel were solicitedin March 1978 from contractors owning vessels that were designed to operate in deep water. Only one vessel, the Discoverer Seven Seas, was fully equipped to drill in 5000 feet of water. The Others would have required modifications or equipment additions to enable them to operate at that depth. In view of the very complete equipment and services package offered by the Discoverer Seven Seas. it was selected as the best alternative.
The Discoverer Seven Seas, a dynamically positioned drillship owned by Offshore International, S.A.. was built in 1976 under long term contract to a group of operators known as SEAGAP. The Discoverer Seven Seas had drilled eight wells prior to the H-28 well, in water ranging from a shallow 362 feet to record setting depths. In 1978 the Discoverer Seven Seas established a deepwater record offshore the Congo in 4346 feet of water only to surpass its own record in February 1979 by drilling offshore Spain in 4441 feet of water.
SEAGAP made the Discoverer Seven Seas available to Texaco by reassigning the contracts for the Discoverer Seven Seas and all associated service for the duration of the Gander Project. With the vessel SEAGAP also supplied w considerable amount of operator- owned equipment including additional marine riser to supplement that owned by OlSA, a spare blowout preventer stack, drilling tools, backup wellhead equipment and running tools.