Sea trial investigation for dynamic load compensation effect evaluation on novel soft hang-off system

Offshore drilling activities have been significantly impacted by extreme storm conditions as oil and gas development has moved into deeper water. Under the situation of the imminent arrival of a typhoon, retrieval of the whole drilling riser is time-consuming and tedious. A novel soft hang-off system under hang-off and transit operations is proposed and developed to solve the low-efficiency and time limitation for risers' retrieval. The hang-off joint system suspends the drilling riser and the hydraulic system is designed for dynamic load compensation. Sea trial for enhanced hang-off mode with hang-off joint, non-differential control dynamic load compensation mode at hang-off operation and passive compensation mode at transit operation are conducted to evaluate the load compensation effect equipped with novel soft hang-off system compared with conventional hard hang-off mode. Results on dynamic load compensation effect are discussed. The novel soft hang-off system is of high application value for deepwater drilling engineering.

Automated summary

This study proposes and develops a novel soft hang-off system to solve the low-efficiency and time limitation issues in retrieving risers during deepwater drilling operations. Sea trials are conducted to evaluate the load compensation effect of the system, and it is found to have high application value in deepwater drilling engineering.