Globally, oil and gas reserves in deepwater basins represent a massive opportunity to supply the energy needs of the world. To date, deepwater exploration has resulted in the discovery of approximately 50 billion barrels of oil equivalent, 30% of all recent oil discoveries. The estimated total potential of the deepwater is around 150 Billion boe. Shell is a leader in deepwater, producing some 720,000 boe in water depths over 500m.
Along with the large reserves from deepwater fields comes a high price tag for development. Exploration and development costs for a typical 500 million barrel field can easily exceed one billion dollars (US). To drive down the high costs of deepwater exploration and development, Shell invests in an ongoing program of Evolutionary Technology for deepwater. The focus of the deepwater Evolutionary Technology effort is improving deepwater exploration capabilities and well productivity, while finding ways to significantly reduce drilling and production costs. Among the recent advances is Shell’s application of a safer, less costly, and more efficient technology for drilling deepwater wells – the Surface Blow Out Prevention package (SBOP).
The SBOP forms an integral part of Shell’s ‘Floating Toolbox’ concept. Novel technologies allow the use of much smaller, 3rd generation rigs, as opposed to the more expensive 5th generation rigs. This results in improved rig availability, lower day rates and reduced development time. The ‘floating Toolbox’ typically consists of some or all of the following: a small deep water rig, SBOP, a subsea shut-off and disconnect device, a pre-laid mooring package and expandable tubulars.
Shell’s SBOP package replaces the conventional subsea blow out preventer - a massive 650,000 pound unit - with a conventional BOP unit on the drilling rig and a simple, lighter weight unit at the sea floor. This unlocks significant cost savings per project:
- enables more efficient drilling operations (seabed deployment of the BOP, and riser are typically very slow operations);
- extends the technical operating envelope of lower cost, older rigs into the deep water; increases the number of rigs available;
- increases the number of projects that can be absorbed onto a rig sequence
- allows wells to be drilled in a safer manner than with conventional rigs.
The reduced rig rates for SBOP wells mean that overall well costs can be reduced by up to 30% compared to conventional well costs (less than the overall rig rate savings due to the fact that ancillary service costs are unchanged).
The SBOP system has been used on the semi-submersible drilling rig the Stena Tay to successfully drill a well in approximately 3000 meters (almost 10,000 feet) of water, offshore Brazil.
Upon completion of activities in Brazil, the Stena Tay will set sail for Egypt where she will drill in Shell’s Northeast Mediterranean Deepwater Concession, in the Nile Delta. A three well sequence is scheduled to begin in September 2003 utilizing SBOP technology – a first for Egypt. The wells will set water depth records for both Egypt and the Mediterranean, with plans for drilling in water depths greater than 2450 meters (>8000 feet). In addition, the wells be the second deepest water wells (after the Brazil well) ever drilled using SBOP technology.
Shell’s Evolutionary Technology Program enhances our, and our partners’, ability to efficiently explore, develop, and produce oil and gas under challenging environments, such as deepwater. SBOP is a key example of the benefits that derive from Shell’s investment in new and innovative deepwater technologies. Shell will utilize SBOP in ultra deepwater for only the second time offshore Egypt, where the Stena Tay will further advance the frontiers of oil and gas exploration in Egypt.