A study of exploratory well data revealed particular problems that faced the development drilling program for the Gulf of Mexico, GB 426, tension leg platform (TLP) in 2,862 feet [872 m] of water. Reservoir depths of up to 19,500 feet [5,944 m] TVD, and 7-inch [178 mm] production casing requirements, when coupled with limitations imposed by conventional subsea drilling technology, led to potentially troublesome and expensive well plans.
A Two Riser System (TRS) for drilling was developed and is being utilized to reduce drilling time and cost. This is accomplished by execution of well plans which circumvent conventional subsea drilling technology limitations. Development drilling is now being conducted prior to installation of the TLP and has shown the TRS method for drilling deep development wells in deep water for the Auger TLP to be safe and cost effective.