Reactive formations, resulting in wellbore instability, can obstruct the running of casing, liners, and completions. This problem is particularly acute in highly deviated, complex wellbore geometries, and long horizontal sections, where increased exposure time can lead to deteriorating hole conditions.
This paper reviews the use of a novel fluid-powered Turbine Reamer Shoe (TRS) to successfully run 9⅝in casing, 7in drilling and production liners, and 4½in liners and completions through problematic intervals and hole conditions. The downhole turbine provides high speed reamer rotation without rotating the entire string, and requires minimal modification to standard running practices.
The 9⅝in and 7in casing/liner running turbines present a further novel design feature: an unobstructed through bore (at API drift ID of the string on which it is run) for rapid drill out and drilling ahead.
Results from over 30 onshore and offshore wells from the Manifa development, and several other fields, including Berri, Zuluf, Qatif, and Safaniya are analysed.
The TRS is now becoming a technology of choice in the planning of challenging wells, to mitigate the risk of sticking, and to reduce the flat time and HSE exposure involved in conditioning the wellbore and re-running casing, liners, and completions.