Jack-up rigs are mobile offshore drilling units used to drill and extract oil and gas from formations beneath the seabed. These rigs are towed to designated locations where their legs are lowered to ensure stability against geotechnical, environmental, and operational loads. The legs of a jack-up rig feature called spudcans, which act as shallow foundations, providing additional resistance due to their enlarged base areas. In the current study, a jack-up rig is scheduled to move to a site in the Middle East. Specific geotechnical information for the site, which is crucial for predicting leg penetrations, is not available. Instead, limited geotechnical data from nearby historical sites, which only provides general soil information, was used to create a generic geotechnical design profile. Leg penetration analysis was performed according to relevant standard codes of practice, predicting leg penetrations for both lightship and full preload conditions. Historical data from previous jack-up rig moves in the same region was reviewed and compared with the analysis results. The risk of the jack-up rig punching through a strong layer underlain by a weak layer was assessed, and recommendations were provided. When the jack-up rig arrived at the location, the observed penetrations closely matched the ESTIMATED values, validating the overall approach and analysis.

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Estimated and Observed Leg Penetrations of a Jack-up Rig Move in the Middle East, Using Nearby Historical Geotechnical Data

  • H. C. Sumanth,
  • A. R. Nandhagopal,
  • C. R. Parthasarathy

摘要

Jack-up rigs are mobile offshore drilling units used to drill and extract oil and gas from formations beneath the seabed. These rigs are towed to designated locations where their legs are lowered to ensure stability against geotechnical, environmental, and operational loads. The legs of a jack-up rig feature called spudcans, which act as shallow foundations, providing additional resistance due to their enlarged base areas. In the current study, a jack-up rig is scheduled to move to a site in the Middle East. Specific geotechnical information for the site, which is crucial for predicting leg penetrations, is not available. Instead, limited geotechnical data from nearby historical sites, which only provides general soil information, was used to create a generic geotechnical design profile. Leg penetration analysis was performed according to relevant standard codes of practice, predicting leg penetrations for both lightship and full preload conditions. Historical data from previous jack-up rig moves in the same region was reviewed and compared with the analysis results. The risk of the jack-up rig punching through a strong layer underlain by a weak layer was assessed, and recommendations were provided. When the jack-up rig arrived at the location, the observed penetrations closely matched the ESTIMATED values, validating the overall approach and analysis.