The US Geological Survey's recent world resource assessment contains much important information about future oil and gas volumes that might become recoverable. The gas estimate is slightly lower than the previous assessment, but at a mean of 15,401 tcf, it's still an impressive volume (see p. 79).
It is useful to remember that many of the world's inhabitants do not yet take gas and power for granted. One emerging project provides an example of the exploration, marketing, and other challenges involved in turning some of those resources to reserves and then burnable fuel.
Orange basin gas
In southern Africa, an area of 1.75 million sq miles in six countries with 85 million people, is practically void of oil or gas production.
Gas has been found in the Atlantic off Namibia and off South Africa but never developed.
Now subsidiaries of Denver companies Forest Oil Corp. and Anschutz Corp. are reassessing two previously drilled gas discoveries off western South Africa. Neither has been declared commercial.
Forest said its work revealed that as much as 2.5 tcf of gas might ultimately be recovered from the Lower Cretaceous sandstone reservoir associated with the 1988 AK-1 discovery well and that the reservoir will almost certainly yield 200 bcf.
This minimum estimate includes only areas updip from AK-1 as delineated by a 3D seismic survey Forest acquired last year. That survey also identified "substantial gas potential" on separate prospects on 8-million-acre Block 2, Forest said.
The AK well cut 207 ft of pay at 10,627-11,091 ft, and three zones flowed a combined 52.8 MMcfd of gas and 342 b/d of condensate.
If AK is deemed commercial, South Africa will have the right to back in for a 10% interest.
Forest and Anschutz also hold 70-30 interests in the 5-million-acre Block 1 just north of Block 2 and bordering Namibian waters.
The companies acquired rights to Block 1 in November 1999 and have completed a 450-mile 2D seismic program there. Block 1 has one previous discovery, AF-1, which flowed 32.4 MMcfd of gas.
Development outlook
Commercializing AK and AF gas could involve challenges, including lack of pipelines, similar to those of Kudu gas field off southern Namibia.
The AK gas discovery is in 800 ft of water 48 miles southwest of the Orange River mouth.
Forest is investigating gas markets and gas-power and gas-liquids conversion technologies to commercialize AK. Earliest production would not occur before 2004, and there's no assurance that the AK-1 gas will be deemed commercial, Forest cautioned.
South Africa imports the equivalent of 2 bcfd of gas. If used locally, the gas would be a boon to at least a small part of an area nearly half the size of China. If not, other economic benefits should accrue.