The current trend for highly mobile deep water rigs is for bigger drillships and semi-submersibles with ever increasing building costs.
Stena Drilling propose a smaller drillship or semi-submersible, the DrillSLIM drillship or DrillSLIM semi-submersible to dramatically reduce the costs of wells in water depths up to 7500ft and relatively benign conditions.
WELL CONTROL EQUIPMENT
- 13 5/8” 10K LBOP and LRP for subsea shut off and disconnect with multiplex control
- A 13 5/8” ID, 10K riser with kill and choke lines
- 13 5/8” 10K UBOP above the high pressure riser with hydraulic control
- MPD/UBD chock manifold
- Rotating control head for MPD or UBD
USE OF ADVANCED TECHNOLOGIES
Managed Pressure Drilling (MPD) and Under Balanced Drilling (UBD). The HP riser and well control equipment allows various methods of MPD and UBD to be employed.
DUAL GRADIENT DRILLING
This technique can be undertaken with a subsea pump pumping return drilling fluids to surface, creating a closed loop drilling system.
- Single mast with a 500ton ram type hoist, top drive and triple joint racking
- Skidding and trolley system to handle BOP’s and subsea Xmas trees
- Trip saver to support subsea pump return for DGD
- 3 knuckle boom cranes
- 500 Tonne AC top drive with auxiliary 49 1/2” rotary table
- Mud pits of 6,460bbls and conventional mud treatment package
- Three triplex pumps with 7,500psi fluid ends
- 6 x 60m³ dry bulk storage tanks
- 22,500ft of 5” and 3 1/2” drill strings
DRILLSLIM BASIS OF DESIGN
- Drilling MPD, UBD or Dual Gradient Riserless Drilling
- High pressure riser and sub-surface BOPDrill, complete and intervene in subsea wells
- Ability to drill a subsea 15,000ft slim well in 7500ft water depth
- Well intervention and TTRD capability
The DrillSLIM drillship is based on 150m x 30m Houlder and Keppel Fels design providing maximum flexibility with a hull form developed to reduce motions and enhance sea keeping capabilities.
The vessel is dynamically positioned to IMO Class 2 and has accommodation for 123 persons. A telescoping mast allows passage through the Suez and Panama Canals as well as the Bosphorous Sea.
The DrillSLIM semi-submersible has the same drilling package and BOP / riser system as the DrillSLIM drillship although is based on a Keppel Fels DSS30 design hull without telescoping mast.