Inelastic Capture Neutron Logging to Identify Bypassed Hydrocarbon in Complex Secondary-Recovery Environments

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractInelastic capture neutron logging (IC) has been used successfully to identify water influx and by-passed hydrocarbon in the mature oil fields located on the North Slope, Alaska. The North Slope has had commercial production since 1977. Production from these fields are enhanced by secondary recovery techniques including water flooding using Beaufort Sea and produced water, natural gas re-injection and miscible fluid injection techniques. The uses of traditional cased-hole evaluations (sigma and porosity interpretation from pulse neutron and cased hole neutron logs) are limited due to the complexity of the secondary recovery techniques including wide variations in the salinity of injected water. Beaufort Sea water salinity varies widely through out the year due to the influx of fresh water during the spring run off. Inelastic capture neutron logging and interpretation has allowed identification of remaining and by-passed oil and has aided in the planning of sidetrack wells to tap additional reserves. Ambiguities arising out of formation water salinity uncertainties have been clarified through the use of inelastic capture neutron logging techniques.

Tecnicas geoestatisticas aplicadas na modelagem da saturação de oleo

“…No primeiro caso, onde são utilizadas na localização de pontos onde ocorrem acumulações remanescentes, pode-se citar os trabalhos de Wolff et al (1993) no Campo de Bahrain, Barein e Hupp et al (1999) no campo maduro de North Slope, Alaska.…”

“…Segundo Hupp et al (1999), tem permitido identificação precisa de reservas remanescentes em ambientes diversos, onde a interpretação das informações advindas da ferramenta resultaram num acréscimo de produção e aumento da vida dos poços.…”