The Science of Capping a Subsea Well Blowout

As part of any Source Control Emergency Response Plan (SCERP), capping a subsea well blowout is a significant contingency operation that requires attention to many details to ensure that an operator is prepared to manage the risks involved and to achieve the desired outcome of stopping the flow of an uncontrolled well. The objective of this paper is to identify and describe the technical considerations (the science behind the procedures) that a prudent operator must address to be able to efficiently and effectively store, maintain, mobilize, install and operate a subsea capping stack in a subsea well blowout event. The paper will offer a brief description of the critical design and functionality requirements that were considered in the development of the original capping stacks. It will contain some updated guidance regarding storage, maintenance and transportation of a capping stack to the incident site. This paper will also present the latest review of available installation methods and offer a brief narrative regarding operating procedures. The paper will also briefly relay portions of the newly-released guidelines introduced in IOGP Report 594, dated January 2019, regarding the need for and definition of an effective SCERP. It has been almost 10 years since the last catastrophic offshore well control incident and the industry has responded by building equipment and developing procedures to enable an effective response to a similar incident. However, operating in an offshore environment requires a perpetual risk assessment and constant review and evaluation of contingency plans for all procedures, especially for those relating to protecting the environment. This paper will present an operator with proven guidance statements to enable the operator to properly prepare for a subsea well control incident. This paper will present updated guidance regarding selected technical issues of capping stack design and pertinent updated guidance regarding capping stack storage, maintenance, mobilization, and installation. The paper will also reinforce the newly released SCERP guidance regarding capping stacks in IOGP Report 594, dated January 2019.