Mechanical Analysis of Deepwater Drilling Riser During Inter-Well Towage in Batch Drilling and Completion Operations: A Case Study from Stabroek Block, Guyana

Abstract

In deepwater oil and gas development, conventional well-by-well drilling and completion involve repeated equipment deployment, resulting in low efficiency. The Liza project in the Stabroek Block, Guyana, adopts a batch drilling and completion mode, significantly improving operational efficiency. However, inter-well towage of a suspended riser introduces challenges to riser integrity and safety. This study reviews key technologies in batch drilling and develops a mechanical model for riser hard hang-off using OrcaFlex 11.5 to assess the effects of wave height, wind speed and direction, and towing speed on riser stress and universal joint angular displacement. Simulations under representative Guyana conditions show that riser stress increases with wave height. The most critical scenario occurs when towing against the current with a following wind, where the maximum safe towing speed is 0.80 m/s, governed by angular displacement limits. Additionally, batch operations significantly reduce drilling and connection time and offer environmental benefits. These results provide guidance for optimizing deepwater batch drilling and ensuring towing safety.

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