By Chris Sutton – Partner, Clover Global Solutions, LP
According to the Bureau of Ocean Energy Management (BOEM), “ultra-deepwater” generally refers to drilling at depths of 5,000 feet and beyond. As new technology is allowing for drilling at greater depths, the worldwide supply of ultra-deepwater rigs is on the rise. According to offshore deepwater drilling company, Seadrill, day rates for tendering and contracting ultra-deepwater rigs is back up to the same levels as in 2007 – running about $550,000 to $650,000 per day. These rates have led to longer contract durations and more favorable commercial terms and conditions for operators, making it a popular industry right now.
Above: Production in fields over 1,499 meters will exceed 2007 levels by 2014.
Ultra-deepwater production is expected to grow at a rate of 12% per year until 2030. By 2015, the majority of new offshore drilling projects will take place in ultra-deepwater. However, ultra-deepwater drilling brings special challenges that require new technology.
Challenges of Ultra-Deepwater Production
The main challenges of ultra-deepwater production are related to the extreme environment of operating and drilling into rock, sand, and shale at 10,000 to 11,000 feet below sea-level. Equipment must be able to withstand pressure equal to thousands of pounds per square inch (psi), and temperatures just above freezing. Additionally, rig structures must be tethered to the seabed as there is significant movement both in the structure and the riser creating both safety and operational challenges. Ultra-deepwater facilities are also far from the host platform, and operators need reliable sources of power and communication. Considering these factors, reducing operational risk is a high priority amongst offshore operators. The limited availability of ultra-deepwater rigs also affects the lifecycle phases and timeline of major capital projects involving ultra-deepwater drilling.
Above: The Petrobras P-51 operating in Brazil.
Advances in Technology Making Ultra-Deepwater Drilling Possible
Innovative advancements in technology have allowed more ultra-deepwater fields to be developed. For example, advances in seismic imaging have addressed visibility issues, allowing operators to see fields in 10,000 feet underwater.
Another common problem with ultra-deepwater drilling is salt structures. Seismic imaging is used to look for reserves both onshore and offshore, but doesn’t work well when looking through a salt structure. Thus, other methods of gathering data below the salt must be used; otherwise operators will not know how much the wells will produce. In ultra-deepwater, highly productive wells are a necessity, otherwise the cost of drilling is too high. Often, determining how much a well will produce requires costly, long-term tests.
One offshore technology development company has addressed these challenges by developing a new floating production and drilling unit called the Multi-Column Floater (MCF). The vessel and all associated riser and subsea systems have been engineered to be reconfigurable, reusable and relocatable.
Ultra-deepwater also requires different types of drilling than conventional offshore fields. At the Institute of Petroleum’s Deepwater Offshore conference in London, the president of Chevron Africa and Latin America E&P stated that Chevron expects to test a dual-gradient drill in 9,000 to 10,000 feet of water, which is a technique that has potential to improve safety, drilling performance, well integrity, and predictability.
Conclusion: A Work in Progress
Ultra-deepwater exploration is extremely complex and technical. This complexity will not go away anytime soon. Although ultra-deepwater exploration has come a long way in recent years, the industry still has room for improvement. One goal is to keep current production capability, but with a lower environmental footprint. The use of Floating, production, storage, and offloading (FPSO) units has helped in this area by eliminating the need for long-distance pipelines.
Another goal is to develop and qualify equipment and design codes for drilling wells at pressures beyond 15,000 psi. Doing this will require new well designs, new completion systems, and new rigs, and is a long-term goal for the industry, however as technology advances, there will continue to be more opportunities to develop fields in ultra-deepwater.
Chris Sutton has a sound foundation in the energy sector contracting from both Client and Contractor sides with specific expertise in building alliances to facilitate service capabilities. To contact Chris with any questions or comments, please send an email to Chris.S@clovergs.com.