Capping Stack Technology Comes of Age

Abstract

While several years have passed since the 2010 Gulf of Mexico (GOM) source control incident that caused a six-month drilling moratorium, the industry likely believes it is fully prepared to prevent or mitigate the effects of a similar incident in a timely manner. However, installing a source control device on a blowing well is a technically complex exercise, one that has never been performed; while performing such an operation, one should consider challenges posed by metocean conditions, coupled multiphase hydrodynamics, and multibody interactions that complicate the deployment and docking of a capping stack onto a subsea wellhead. The latest gate-valve technology intended to close against flow presents a more compact option for rapid capping than unwieldy ram-based systems. The speed of deployment of the lighter capping stack is attributed to the availability of suitable aircraft, lifting equipment at the airport or dockside, and an ample supply of suitable deployment vessels. The underlying logistical issues that prevent rapid responses to subsea incidents have not, for the most part, been addressed until now. A development differentia in capping-stack technology has been necessary to exact the speed of response that the industry calls for and to meet the expectations of stakeholders and the general public. Fortunately, the industry now has access to technology that can be deployed to a source control incident in any global location in a matter of days. Sophisticated, high-fidelity simulation, hitherto unavailable, incorporates metocean sea state and uses coupled multiphase hydrodynamics and multibody interaction effects of vessel motion, suspension system dynamics, and the hydrodynamics of the capping system within the unstable blowout forces to create an accurate analysis that addresses plume and landing-force analysis at the wellhead. Coupled with the tools to accurately simulate the effects of the force dynamics from surface to wellhead to complete the entire process, the advances accompany the new capping design and enhance the ability to determine landing capability, heralding further advancement in source control technology and techniques.