Anderson, T. (Chevron) | Fontenot, C. (Chevron) | Davey, R. (Chevron) | Dugas, J. (Quail Tools LP) | White, B. (Quail Tools LP) | Hamilton, K.A. (C-FER Technologies) | Beauchamp, P.S. (NOV Grant Prideco) | Karlapalem, L.C. (NOV Grant Prideco) | Muradov, A. (NOV Grant Prideco) | Brock, J.N. (NOV Grant Prideco)
A two-year comprehensive effort to design, test, manufacture, and deploy a new high-pressure completion tubular for Chevron's deep-water Gulf of Mexico operations is presented. The completion application expected harsh, aggressive loading modes and high pressures to be encountered. The major challenge was to design, test and manufacture a subsea completion string that would provide efficient hydraulics during the fracturing operations while ensuring mechanical and pressure integrity.
Results from comprehensive finite element modeling designed to evaluate the application loads are presented. An extensive physical test program to evaluate the structural integrity and sealability performance was conducted. The test included a series of combined load conditions which included axial loads (maximum 1,100,000 lb. tension, 215,000 lb. compression), internal (maximum 29,920 psi), external (maximum 25,279 psi) pressures, and bending loads (3°/100 ft. curvature). Multiple-step load cycles were conducted at both room and elevated temperatures.
Compared to earlier designs, the new 5-7/8 in. tubular design has double-start thread form which provides cost savings by reducing the make-up time from stab to shoulder by approximately 11 seconds saving trip time. The design's unique dual-radius thread root offers a step-change improvement in fatigue resistance. The new design also provides significant reduction in repair cost in comparison to earlier designs. The initial deployment of the new design is planned for wells in the Chevron-operated Jack and St. Malo oilfields which are located 40 km from each other (
As deep-water drilling continues to expand, high-performance completion tubulars must evolve to meet mechanical requirements and provide cost saving, efficiency, and safety.