Later this summer Chevron is due to launch a pilot steam flood project aimed at boosting crude oil output in the partitioned neutral zone (PNZ) which is shared between Saudi Arabia and Kuwait. Steam flooding is a reservoir management technique that increases oil recovery and value. It involves injecting steam into a reservoir to warm the oil until it reaches a syrupy consistency and can be pumped out. If successful, tens of billions of barrels of reserves could eventually be released across the Middle East. However, technical challenges remain. Chevron has successfully applied the technique in California and Indonesia where the oil fields are sandstone. In Saudi Arabia and Kuwait they are of carbonate rock such as limestone.
According to a report in the Financial Times, steamflooding has never been used in carbonate fields, because the steam would dissolve minerals in the rock, clogging up the reservoir and the wells. In the large-scale pilot that Chevron plans to launch in the summer, following a small-scale test that concluded last year, it will use steamflooding in the Wafra field in the PNZ to see if those problems can be overcome. Wafra currently produces an estimated 550000 barrels/day.
The FT also pointed out that Chevron's plans follow its success in extending its licence from the Saudi government to operate in the neutral zone for a further 30 years: foreign companies are not generally allowed any share in Saudi Arabia's oil production, which is dominated by Saudi Aramco, the national oil company. Chevron first used steamflooding in the mid-1960s to optimise recovery from mature heavy-oil fields in the San Joaquin Valley in southern California.
The successful San Joaquin Valley venture provided important lessons for when the company later embarked on the world's largest steamflooding venture at the Duri Field in Indonesia's Sumatra province in the mid-1980s. The Duri steamflood project, which involved drilling more than 5000 wells, covers more than 18000 acres. The operation more than tripled Duri's daily oil production, enabling the field to surpass the two billion-barrel mark of total oil production in 2006.
In a related development, the company also announced in June that its wholly owned subsidiary Chevron Pacific Indonesia has started producing crude oil from the North Duri Field Area 12 in Indonesia, where Chevron produces nearly half the nation's crude oil.
First oil was achieved on 14 November last year and production is projected to increase to 34000 barrels of crude oil per day by 2012. Initial production from North Duri Area 12 will increase with the application of steamflood technology next year.
"The Duri Field is a remarkable base business success for Chevron. With the application of technology, we have been able to extend the life of this field and increase the amount of oil ultimately recovered," said George Kirkland, executive vice president, upstream and gas, Chevron.
North Duri Area 12 represents the latest expansion of the Duri field, the largest producing field Chevron operates in Indonesia. The Duri Field currently produces nearly 200000 barrels of crude oil per day. Discovered in 1941 on the island of Sumatra, the field is one of the world's largest steamflood projects.
Another aspect of reservoir management technology can be applied before a field begins production. An example here is the deepwater Benguela Belize-Lobito Tomboco project in Angola, where Chevron employed integrated reservoir management techniques to design a field development plan that would increase production and reserves.
The company is also applying real-time advanced reservoir management practices to increase oil production from the field as actual production data becomes available. One key to achieving these production gains is having a framework of standardised reservoir management practices that can be consistently applied by its teams around the world.
The company has also pioneered Intersect, a reservoir simulation tool. This uses parallel computing, dividing large problems into smaller pieces and solving them simultaneously. In addition, Intersect uses unstructured gridding, depicting reservoirs like 3D jigsaw puzzles with hundreds of thousands of curvy cells
