Tullow Oil has installed jetted well conductors at deep water sites offshore Ghana. Variability in axial load-carrying performance was observed.
A study was initiated to understand the various influences on conductor performance, distinguishing between those that were non-controllable (e.g. geology, soil conditions) and those that were controllable (e.g. installation practice, well design). Influence metrics were developed and systematically examined against conductor performance to search for trends and relationships.
An understanding of the expected regional soil variability over the development area was reached through an engineering geological review. The study defined future best practice recommendations for conductor jetting, which now constitute established installation practice for ongoing operations in the area.
This paper describes the study and its findings, and emphasizes how its success hinged on Tullow Oil’s ability to make available geophysical and geotechnical data, together with comprehensive jetting and drilling operations records.