Static formation temperature: critical analysis

Abstract

Oilwell temperature readings are used to ascertain static formation temperature. Although test records are usually considered to reflect true temperatures, in cases where maximum temperature gages are used and water or low-GOR oil is produced, values that are deemed real may in fact prove overestimated. Furthermore, exirapolations must be performed on temperatures as measured during logging operations, since the circulation of drilling mud yields recorded values below true values. ln these cases, both the poor quality of temperature data and the inadequacy of extrapolation methods in representing physical well conditions con­tribute toward incorrect estimates of static temperature. Cautious data analysis can help improve this situation.