FLEXIBLE, HIGH TEMPERATURE THERMAL INSULATION MATERIALS FOR SUBSEA WELLHEAD AND PRODUCTION EQUIPMENT

摘要

As oil and gas wells are being drilled in deepwater, hydrate formation in the well has become a major concern. During a production shut down, gas hydrates can form and plug the bore of a subsea tree, tree piping, jumper, manifold and flow lines. During shut downs, hot produced fluids become stagnant and are cooled by the surrounding cold water, resulting in hydrate formation. Thermal insulation is necessary to slow down this cooling process to prevent hydrate formation until the well production or hydrate inhibitor injection can be restored. Currently available insulation materials for subsea applications are rated for internal temperatures of up to 121℃ (250℉). These materials include NovoTherm, urethanes, and epoxy/syntactic foams, and vulcanized rubbers. These materials may thermally age at above 121℃ (250℉) such that the insulation bond line will become weakened or softened over time. Recently, insulation that will withstand 177℃ (350℉) internal temperatures for high temperature, high pressure (HTHP) projects are being required by operators. Two new insulation materials, proposed for use on subsea wellhead and production systems at temperatures up to 177℃ (350℉) will be discussed. The first material is based on addition cured silicone elastomer. The second material is based on a flexible Novolac epoxy. Both materials are cast in place into molds, have high tensile elongation, and possess the thermal properties necessary to meet cool down requirements for subsea production equipment. These materials are being proposed for use on manifolds, jumpers, production trees, and other subsea equipment.