Among the most common designs built in the US, the Tarzan is the smallest class, while the Super 116E and 240C are approximately the same size (Fig. 5). The Super Gorilla is the largest rig class by a large margin.
LeTourneau Tarzan
The Tarzan is designed for shallow-water (less than 300 ft), deep drilling (35,000 ft) in moderate environments. The Tarzan was designed to provide high pressure-high temperature (HPHT) drilling at a low cost, but the design has not been internationally successful. Four Tarzan class rigs exist, all built between 2004 and 2008 at the Vicksburg, Miss., shipyard and all owned by Rowan. Unlike more-traditional LeTourneau designs, the Tarzan uses three tubular chords with opposed pinions.
LeTourneau Super 116E
The LeTourneau Super 116E evolved from the LeTourneau 116C, which was first built in 1978 and is considered one of the workhorses of the industry. The first Super 116E was delivered in 2007; eight have been delivered through 2011. The Super 116E is designed for moderate locations and 350-ft water depths and is well suited to shallow, moderate environments such as the Persian Gulf. Like many classic LeTourneau-designed rigs, it has square legs, each with four teardrop chords. In recent years, several Super 116Es have been assembled at the AmFELS shipyard in Texas; worldwide, 12 Super 116E rigs are under construction. Customers include Petrobras, National Drilling, and PetroVietnam Drilling. In 2012, prices are typically less than $200 million and can be as low as $160 million for rigs designed for the Persian Gulf with water depth capabilities less than 250 ft.
LeTourneau 240C Workhorse
Compared with the Super 116E, the LeTourneau 240C can work in deeper water with a greater variable load and a larger cantilever reach. The 240C uses a unique leg design with four tubular chords. The 240C is a relatively recent rig design, and only three have been delivered, all built at the LeTourneau shipyard for Rowan. In 2011, KS Energy ordered two 240Cs from a COSCO shipyard in China for $194 million each. These represent the first non-US sales of a 240C design license.
LeTourneau Super Gorilla XL
The LeTourneau Super Gorilla XL is among the largest jack ups in the world, capable of drilling to 35,000 ft in harsh environments in water as deep as 550 ft. The Super Gorilla XL is an upgraded version of the Super Gorilla. The Bob Palmer, the only rig of its class, cost $326 million to construct in 2010. It has been let for nearly $300,000/day on a long-term contract with Saudi Aramco from 2011 to 2015.
