Self-Erecting Tender Rigs (SETR’s) have been used in South East Asia, West Africa and the Middle East for 30 years for drilling development wells from fixed platforms.
Inherent in the SETR concept is that equipment required to support the drilling operation such as power, living quarters, etc, is located on the tender, while only equipment actually needed for drilling such as the derrick, topdrive, BOP, etc are installed on the platform. Compared to the use of a platform rig the design load and required deck area of using an SETR is thus only about 1/4 of that needed for a platform rig of comparable capacity.
So far tender rigs have mainly been used for development drilling in water depths down to 800 ft. And this will most likely remain their main application also in the near term.
However, with increased focus on use of dry completions in deep water with the Xmas trees installed on a floating platform like a TLP or SPAR - the self-erecting tender rig concept will present many benefits for field development also in deep water, particularly for marginal field development, where the field economics may depend on solutions using small, remote controlled wellhead TLP’s.