Jackup Mobilization in Hazardous Soils

Abstract

Summary: This paper presents two case histories of jackup rig mobilizations to locations identified as high risk for uncontrolled leg penetration or punchthrough. The punchthrough risk is defined through an overview of the soil analysis work completed for each location. The effectiveness of remedial operations, known as "swiss cheese" drilling, in mitigating the punchthrough risk for the subsequent jackup mobilizations is reviewed. It is concluded that "swiss cheese" drilling can be effective in reducing punchthrough risk. Advance planning is important, and recommendations are provided to assist in effective punchthrough mitigation.