Despite multitier safeguards in any drilling/production operation, blowouts do occur. Over the past few decades many blowouts with serious consequences happened, such as Ekofisk Bravo blowout, Ixtoc I blowout, Enchova Central blowout, Kaixian blowout, and Deepwater Horizon blowout. SINTEF database (2016) reported a total of 263 blowouts incidents from 1980 to 2012 in the US Gulf of Mexico (GoM) Outer Continental Shelf (OCS) and North Sea. Thus, blowout prevention plays a crucial role in planning and decision making during any well activity. To design an efficient blowout prevention program, blowout release mechanism needs to be understood. Daily and total release of hydrocarbons from a blowout are very important parameters in designing prevention and mitigation plans. This requires a model that dynamically couples the wellbore flow to that from the reservoir.
This paper presents several notable blowout incidents first. Then we discuss a blowout release model that couples the wellbore and the reservoir. Different aspects of blowout prevention are then presented and analysis of needed engineering and organizational actions are discussed. Well control barrier concepts—where barrier elements are primarily divided into operational or physical barriers and organizational barriers governing the total system—are then presented. We then discuss a detail review of gas kick—a major precursor to blowouts and then propose a leading indicators-based approach to provide early warning of probable blowouts from kick response and long-term organizational safety performance indicators. The paper then discusses current practices; focusing on consequence and risk-based assessments of a blowout. The last section presents quantification methods for blowout risks, where an example of risk-based assessment of blowout event based on our proposed modeling tool is given.
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