--> Abstract: Reservoir Characterization of the Korolev Field, North Caspian Basin, Kazakhstan, by Kevin L. Putney, Joel F. Collins, Paul M. Harris, Akmaral Zhumagulova, and Dennis J. Fischer; #90039 (2005)

Datapages, Inc.Print this page

Reservoir Characterization of the Korolev Field, North Caspian Basin, Kazakhstan

Kevin L. Putney1, Joel F. Collins1, Paul M. Harris2, Akmaral Zhumagulova3, and Dennis J. Fischer3
1 ExxonMobil Development Co, Houston, TX
2 ChevronTexaco Energy Technology Company, San Ramon, CA
3 Tengizchevroil, Atyrau, Kazakhstan

Korolev field is an isolated carbonate platform located 15 km. from the better-known Tengiz field. It was discovered in 1986 and had been characterized as a smaller version of the 1979 Tengiz discovery due to similarities in stratigraphic age, reservoir thickness and oil properties. However, new drilling at Korolev has identified key differences between the two fields that impact assumptions about hydrocarbon distribution and producibility. Further insights on reservoir performance have also been gained since Korolev began producing in 2001.

Differences in Korolev and Tengiz reservoir properties were apparent during drilling. Unlike Tengiz, where drilling circulation losses are prevalent only in slope facies surrounding the platform, lost circulation occurs in both the platform and slope at Korolev. Lost circulation is commonly associated with relatively thin zones of high permeability that greatly enhance well productivity and reservoir connectivity. Pressure vs. depth measurements obtained in new wells and pressure transient tests between producing wells provide supporting evidence for pressure communication throughout Korolev field.

Pyrobitumen is present as a pore-filling cement at Korolev and Tengiz but its distribution varies between the two fields. Tengiz slope facies contain elevated volumes, commonly near lost circulation zones, while Tengiz platform facies have much lower volumes. In contrast, Korolev platform and slope facies both contain high pyrobitumen volumes thought to be associated with increased frequency of high permeability zones. The high degree of connectivity in the Korolev platform is thought to result from dissolution and diagenesis associated with multiple pore volumes of fluids spilling from Tengiz into this much smaller field.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005