Risk Analysis of Deepwater Managed Pressure Drilling Based on Improved Borda Sequence Value Method

Deepwater pressure-controlled drilling accidents are frequent, but their causes are not well summarized. Traditional risk matrix analysis methods often result in the formation of risk “knots” due to imprecise risk level derivation. To address this issue, a risk factor analysis table based on research and field data on deepwater pressure-controlled drilling accidents is developed in this paper. Borda's sequential value method and improved computational formulas combined with matrix analysis were used to determine risk levels and rank four typical accident risk factors and identify risk factors that are likely to cause these accidents. Our findings suggest that the Borda ranking method mitigates the overall risk magnitude and enables drillers to focus their attention on regions with higher risk rankings. Analysis of four typical incidents reveals that higher risk rankings correspond to higher priorities and require greater attention from personnel. This study demonstrates that the modified Borda ranking method is able to classify and rank the risk of pressure-controlled drilling accidents in detail, providing operators with an effective tool to reduce the frequency of accidents.