Found in 1953 by American Independent Oil Co. (Aminoil - now Texaco), Wafra is the largest of the three onshore fields. It went on stream in 1954. Its reservoirs range from shallow to Paleocene-Eocene Fms. (Hundreds of its 430 wells were set ablaze by the Iraqis. Because of low pressure, the
Wafra's development in the 1980s was done jointly by KOC and Texaco. Shallow well drilling and workover services were tendered in April 1990. After the war, the field was rehabilitated together with South Fuwaris and South Umm Gudair. Now they have related production and gathering systems. In Oct. 1998 Texaco and KOC had a new discovery at the Humma 4 well. It tested 3,400 b/d of 32 deg. API oil near Wafra field. Texaco completed seismic work by mid-1999 and then drilled two delineation wells. The Humma field was developed subsequently and tied to Texaco's oil production system at Wafra.
The Wafra system includes North Fuwaris, a structure to the west. Production before Iraq's invasion exceeded 85,000 b/d of 24 deg. oil, with 3.4-3.6% S, processed at Mina Saud and Mina Abdullah refineries. It had been shut down for some time in the 1960s, when desulphurisation facilities were being built.
Texaco's output averages 270,000 b/d, up from 100,000 b/d in 1991/92 and 120,000 b/d in 1995, compared to 140,000 before the 1990 Gulf crisis. In March 1995, KOC and Texaco launched 3-D seismic surveys and a $600m plan to raise the area's capacity to 300,000 b/d by mid-1999 and 420,000 b/d by 2005. The surveys covered a deep reservoir of light oil in Wafra found by Texaco in early 1993 and, on the Saudi side, the Humma reservoir which has light oil as well. Development was to involve the drilling of 500 wells.
Onshore oil reserves, including South Fuwaris and South Umm Gudair, were estimated at 3.5 bn barrels. The operator on the Saudi side is Saudi Arabia Texaco. On the Kuwaiti side SAT acts on behalf of Wafra Oil Co.
South Fuwaris, found in 1962 and on stream in 1964, is a small field where 23-26 deg. API oil with 3.5% sulphur is produced from a Ratawi limestone, at the rate of about 2,500 b/d. South Umm Gudair, found in 1966 and on stream in 1968 near the Kuwaiti border, is an extension of Umm Gudair. Its reserves were estimated at 450m barrels of 24.3-27 deg. API and 3.5% S oil. Before the Gulf crisis it was producing 40,000 b/d, compared to 51,000 b/d in 1979, from Minagish Oolites of the Lower Cretaceous Ratawi group.