Letters

April 5, 2004
In Maureen Lorenzetti's article "Saudis refute claims of oil field production declines (OGJ, Mar. 8, 2004, p. 24), the oil in place of Saudi Aramco was given as 700 billion bbl, with 238 billion bbl of contingent resources.

Saudi oil in place

In Maureen Lorenzetti's article "Saudis refute claims of oil field production declines (OGJ, Mar. 8, 2004, p. 24), the oil in place of Saudi Aramco was given as 700 billion bbl, with 238 billion bbl of contingent resources.

Following the SPE/WPC/AAPG rules (mentioned by Saudi Aramco in its Feb. 24 presentation), "Contingent resources are those quantities of petroleum which are estimated, on a given date, to be potentially recoverable from known accumulations, but which are not currently considered to be commercially recoverable."

It is obvious that Saudi Aramco officials Baqi and Saleri confuse contingent resources with unrecoverable resources. In fact, they report only 131 billion bbl as proved developed as end 2003 and 129 billion bbl as proved undeveloped. Some of those 129 billion bbl could be considered as contingent resources.

Reserves estimate is a difficult problem which needs to be strict on definition and wording.
Jean Laherrere
Independent Geologist
France

Run-time correction

The article "New downhole technologies tackle multifaceted environments" (OGJ, Feb. 23, 2004, p. 45) included outdated run-time averages for Weatherford CBM-ESP and its competitor pumps that are used in coalbed methane production. The current typical run time for Weatherford CBM-ESP pumps ranges between 245 days to more than 1 year in some cases.
William A. Grubb
General Manager, ESP Pumps
Weatherford International Ltd.
Houston

Correction

An error appeared in the letter "Barnett shale," Mar. 8, 2004, p. 10. The number in Line 11 should read "90 MMcfd."