THE WOODLANDS, Texas – The 2013 Deep Offshore Technology (DOT) International conference closed its technical sessions with a panel discussion on improving oil recovery in deepwater fields.
In setting the scene, John Allen of INTECSEA pointed out that improving oil recovery in deepwater fields is a complicated endeavour that must incorporate reservoir management; concept development engineering; the actual subsea production installation; and a host of parts and processes that together comprise an integrated system that can serve for the life of a field.
The key, said Allen, is in having an integrated production model to minimize the number of wells while maximizing the total production. This means incorporating new technology, in particular new modeling techniques that are better, quicker, and include multi-reservoir considerations. Good input is critical to good modeling, he stressed.
Øistein Bøe, VP of Petroleum Technology for Mature Fields, affirmed these themes. “Statoil’s approach is shown in its saying ‘IOR every single day’,” said Bøe. “IOR equals revenue. A 1% increase in recovery can result potentially in an extra $60 billion. Looking at Statoil’s total worldwide production, IOR represents the largest single ‘oil field’ we operate.”
The key elements of successful EOR, Bøe said, include knowing your portfolio of field prospects; which toolbox to use for enhanced recovery; and allocating a budget for a long-term plan. EOR/IOR projects also need internal management support, and must be in alignment with any project partners. Making a business case for a project goes a long way toward bringing these steps about, he added. Any use of new technology, Bøe noted, “will require an alliance with vendors to be successful.”
Donna Auzenne, Water Flood Optimization Team Leader for Chevron North America Exploration and Production Co., described how her company approaches such projects. “EOR is a cross-function challenge,” said Auzenne. “There has to be an upside potential, all the disciplines need to be involved, and new technologies embraced.”
Business needs drive the development of new technologies. Auzenne cited the development of the enhanced single-trip, multi-frac technology as an example. The challenge that led to this technology was the business need to produce oil from a 1,400-ft thick, high-pressure (20,000 psi) deepwater reservoir. The resulting tools also affected other parts of the fieldwork. The system allowed the use of larger diameter casing to greater downhole depth, which enabled the completion technology.
Auzenne noted that potential future technologies based on past EOR applications will probably include chemical EOR for Miocene reservoirs, and high-pressure gas injection for Wilcox reservoirs, both of which will require new equipment. “We are on the path (to EOR),” she said. “We have more to do, but we can see our way forward.”
Total’s Khalid Mateen also provided his thoughts on EOR planning and execution. “There are challenges in planning EOR projects in deepwater and also limitations compared to onshore EOR,” said Mateen, who serves as VP of Engineering Technology for Total E&P Research and Technology USA.
Offshore developments typically use a much wider well spacing, and the oil found in deepwater tends to be more viscous, he noted. The biggest difference is the cost of drilling each well, and that cost results in fewer wells and less familiarity with the downhole conditions, and with the reservoir.
Total has several initiatives directed at solving some of the deepwater EOR challenges, Mateen noted. These include qualifying a polymer injection process to use in shallow, high permeability reservoirs with high viscosity oil, such as at Dalia. Subsea separation and processing are in application at Pazflor, and Total is participating in development of the SPRINGS sea-water injection equipment.
While there is no “silver bullet” answer to deepwater EOR challenges, Mateen said that it is best to identify an EOR option early, and then employ an integrated approach that involves all disciplines.