An Efficient Modeling and Optimization Approach for Pressure Testing During Reentry Operation of Deepwater Drilling Riser System

Pressure testing should be conducted on auxiliary lines during riser reentry to ensure the seal security of connection positions. The proper setting of the number and positions of pressure testing is essential because it can significantly reduce the high costs of offshore drilling. However, the analysis and optimization models for pressure testing during riser reentry were not resolved satisfactorily in engineering practice. This study proposes an efficient optimization procedure for pressure testing during riser reentry. A time-efficiency evaluation model and a risk assessment model are established based on the pressure testing process and entropy theory. The modified artificial bee colony (ABC) algorithm is used to optimize the pressure testing process by incorporating the above proposed models. The optimization procedure is illustrated by a case study. The optimal results from the proposed procedure are compared with those from the recommended practices. The resulting variabilities due to seal reliability, water depth, and pressure testing time are also discussed. The study shows that the optimization procedure can improve the operation efficiency of the riser reentry process by 20% and 38% compared to two recommended practices. The proposed procedure is verified to be an efficient alternative for decision making in pressure testing to improve the economic efficiency and ensure safety during riser reentry.