Re-entry well operations at Maria Field, Block 16/29a UK Sector, North Sea required jack-up emplacement adjacent to subsea production infrastructure. Operational evaluations for the Rowan Gorilla VII initially highlighted a possible spudcan punch-through condition. Due to the proximity of the starboard spudcan to the nearby production pipeline and uncertainty in the soil conditions, detailed geotechnical analyses were performed to assess potential soil deformation and the associated risk to production infrastructure. This paper presents the challenges associated with interpretation of the soil conditions at this location together with predictions of spudcan penetrations from closed-formed bearing capacity calculations and large deformation finite element (LDFE) analyses. These studies assisted the safe installation of the jack-up unit at the Maria Field. Movement of the pipeline was also monitored during installation of the jack-up unit. Comparisons between the actual pipeline movement and the predicted free-field soil displacements from the LDFE analyses for the pipeline position are presented and discussed.
Khoa D. V. Huynh, Vaughan M. Meyer and Richard J. Pike
Keywords: spudcan, pipeline, interaction
Publisher: DFI