Blow-out incident rate
This value is the number of blowouts reported to MMS by the operator. A blowout, surface or underwater, is an uncontrolled flow of gas, oil or other well fluids into the atmosphere or between the sea floor and the water surface. A blowout occurs when formation pressure exceeds the pressure applied to it by the column of drilling or other fluids in the wellbore.
Source: API RP 75, Recommended Practice for Development of a Safety and Environmental Management Program for Offshore Operations and Facilities: Upstream Segment, Third Edition, May 2004. Global Standards