A Thermally Actuated Gas-Lift Safety Valve

Abstract

Summary Most offshore oil wells use flow-control safety valves that are either actively controlled from the surface or passively actuated by pressure changes. In this paper, we propose a passive, thermally-actuated safety valve that adds redundancy to well systems and significantly increases well safety. We use quasistatic thermal modeling, validated with experimental downhole data, to identify and characterize a suitable temperature regime for shape memory alloy actuation. We develop a complete loading and shut-in procedure with the new valve that is consistent with current practice in artificial lift. Finally, through a true-scale stainless-steel prototype, we demonstrate essential manufacturability and successful valve closure in accordance with predictions.