The Bunker Hunt-British Petroleum Sarir oil field of Libya appears to be one of the 10 to 12 super-giants of the world. Credited with 11-13 billion bbl of oil in place, it is a water-drive field that could, and probably will, recover nearly 50 percent of its total oil. The maximum oil column is 300 ft and the area of surface closure is 155 mi². The field was discovered in November 1961 on a seismically defined structure. Development drilling was continuous through the next 4 years; a pipeline and loading terminal were completed and production was begun in late 1966. The oil reservoir is Cretaceous sandstone on basement, the probable oil source being the several hundred feet of overlying Cretaceous marine shale. Structurally, the field is a combination anticline and high fault-block complex within a broad structural low.

There appears to be good fluid communication throughout the reservoir. Average porosity values are 18-19 percent, and permeability values average several hundred millidarcys, with a few 2-3-darcy streaks. All production is water free. The oil is sweet and sulfur free, though of high paraffin content.

More than 100 wells have been drilled, of which about 60 are on production and 12-14 are awaiting gathering lines; most of the others are observation wells for pressure or fluid control. There was a decline of reservoir pressure during the first year of production; however, in most of the field a sustained water drive is developing. Producing capacities of individual wells range from a few thousand barrels daily to maximum estimated open flow of 28,000-30,000 bbl/day. The field went on production at 100,000 bbl/day, which rose to 300,000 bbl within the first year. Additional field facilities, when installed, will permit even greater increases.