December 2007
Special Report

New Rig Designs: Compact RCR series rigs work in the city, swamp or desert

Dietswell has developed the RCR series, a new drilling concept adapted to tropical and desert conditions.

Vol. 228 No. 12  


Compact RCR series rigs work in the city, swamp or desert

Dietswell has developed the RCR series, a new drilling concept adapted to tropical and desert conditions. This series was designed in response to clients’ request for new solutions and expectations for the highest level of QHSE, fast and high performance for time-efficient drilling, a compact layout with a small footprint and versatile drilling, capable of switching between Reverse Circulation technology and conventional Rotary (RCR) drilling without rig modifications.

The RCR series integrates several innovations including:

  • Hydraulic telescopic mast working without being subject to compression
  • No substructure, but an innovative jacking system to elevate the drill floor up to seven meters
  • Semi-automatic Dual Activity System (SDAS) for handling drill pipe and casing
  • Integrated automatic slip and iron roughneck
  • Compact layout
  • Foldable and integrated steel matting system to spread the rig load instead of a traditional concrete platform.

The advantages of the RCR series include: no large concrete platform needed to spread the rig load (minimizing civil works and reduced impact on the environment), zero-discharge mud system with cutting treatment plant, reduced moving time (three days for 81 mi in desert conditions without crane requirements) and conventional rotary drilling and reverse drilling mode using air-hammer drilling and rotary air-lift.

Reverse circulation technology has some significant advantages compared to traditional rotary drilling for minimizing pollution in aquifers, drilling in fractured formations or very hard formations. The rig has been designed and equipped with reverse circulation tools that allow for drilling holes up to 35-in. diameter. The series allows for a competitive cost-per-foot value.

Rig specifications include:

  • Jacking system for quick rig up/rig down of the mast and drill floor
  • Telescopic mast with a 92-ft (28 m) height, allowing for double drill pipe (Range 2) with a 525,000-lb (238 metric ton) hook load capacity
  • Top drive with a continuous torque of 25,300 ft-lb (3,500 daN-m) at 210 rpm and intermittent torque of 32,400 ft-lb (4,500 daN-m)
  • 31,500 lb (14 mt) snubbing capacity
  • Dual-activity system for safe pipe handling operations at 2,300 ft/h (700 m/h) tripping speed
  • Table opening of 37½ in.
  • Iron roughneck for casing up to 95/8 in., combined with remotely-operated hydraulic slips up to 8 in.
  • 135/8-in. BOP stack and rotating BOP
  • 2,100 bbl (340 m3) mud system with big bag-handling capacity
  • Zero-discharge drill floor
  • Two or three high-pressure mud pumps ranging from 1,000 hp to 1,600 hp
  • Closed-circuit television, gas detection, paging and satellite communication systems.

The first RCR unit was delivered in the spring of 2007 for a project in Africa, where its compact layout permitted the operator to install the rig on a 98x131-ft (30x40-m) barge for swamp operations. The local environment would not allow a normal drilling rig to be used and the RCR rig was a welcome solution, complying with the requirements for size and environmental regulations. The second unit is under construction in France and will be followed by three other units.

The series is proposed in various configurations allowing for operations in different environments including tropical, desert, arctic and offshore (lakes/shallow water/swamps). The rig is also suitable for work in urban areas, where its compact layout in combination with low pollution and low noise emission becomes indispensable.

Dietswell has provided drilling services since 2000 through its four activities: drilling contractor, drilling engineering, rig constructor and rig inspection. The company’s strategy is to develop innovative solutions for challenging drilling environments where existing solutions are not meeting the requirements for safe and time-efficient operations. WO


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