Definition(s)
Loss of Well Control (LWC)
A loss of well control incident is an uncontrolled flow of subterranean formation fluids such as gas, oil, water, etc. and/or well fluids into the environment or into a separate underground formation, in which case it is called an underground blowout.
Source: API STD 65 – Part 2, Isolating Potential Flow Zones During Well Construction, Upstream Segment, Second Edition, December 2010. Global Standards
Loss of Well Control
Loss of well control, as mentioned, means the failure of one or more well barriers [for instance reduction in drilling fluid head leading to influx from the wellbore is failure of well barrier (drilling fluid); this would require closure of the well with the help of BOP to bring the well back under control].
Source: Guidance Notes on Petroleum and Natural Gas (Safety in Offshore Operations) Rules, 2008, Oil Industry Safety Directorate (India), 2012. Regulatory Guidance
Loss of Well Control
Loss of well control as mentioned in the first subsection, means the failure of one or more well barriers.
Source: Guidelines Regarding the Activities Regulations, Norway, updated December 2012. Regulatory Guidance
Loss of Well Control
Loss of well control is any incident that results in:
• An uncontrolled release of formation or other well fluids
• An uncontrolled flow between two or more exposed formations (this includes uncontrolled flow resulting from failures of either surface or subsurface equipment or procedures) or
• A flow of formation or other well fluids through a diverter. Note: IRF (www.irfoffshoresafety.com/country/performance/scope.aspx).
Source: Incident Reporting and Investigation Guidelines, The Canada-Nova Scotia Offshore Petroleum Board and Canada-Newfoundland and Labrador Offshore Petroleum Board, Canada, November 30, 2012. Regulatory Guidance