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Title: Regional implications of the Bashkerian-Serpukhovian reservoir architecture at Tengiz field; Kazakhstan

Journal Article · · AAPG Bulletin
OSTI ID:127633
 [1];  [2];  [3]
  1. Chevron Overseas Petroleum Inc., San Ramon, CA (United States)
  2. Tengizchevroil, Tengiz (Kazakhstan)
  3. VolgogradNIPIneft Institute, Volgograd (Russian Federation)

The super-giant Tengiz Field is a complex Carboniferous-Devonian reservoir. The most common occurrence of higher porosity zones is in the uppermost portion of the reservoir within the Bashkerian to Serpukhovian section. The suite of porous textures containing preserved primary porosity ranges from skeletal and coated grain to mixed particle grainstones, and packstones which display little or no compaction due to early isopachous marine cementation. In some areas, the amount of primary preserved porosity is inversely proportional to th occurrence and amount of crinoids and associated syntaxial overgrowths. Early and late secondary porosity is most pronounced in the upper portions of the reservoir associated with features ranging from multiple short-term exposure events to long-duration unconformities. Lower energy wackestones and mudstones interbedded with higher energy facies cause verticle permeability barriers and baffles. In areas of stacked shoaling cycles in the platform interior, lateral correlation of porosity zones is good. Muddy biolithites tend to be concentrated along the north and eastern portions of the structure and generally contain lower reservoir quality and cause lateral changes in reservoir continuity. Preliminary analysis of facies distribution patterns indicates that the higher energy {open_quotes}windward{close_quotes} direction is not facing into the North Caspian basin, but to the east-northeast into the Emba sub-basin. This allows for a separate exploration play concept around the Emba sub-basin {open_quotes}rim{close_quotes} which would be separate and distinct from the rest of the North Caspian Basin.

OSTI ID:
127633
Report Number(s):
CONF-950995-; ISSN 0149-1423; TRN: 95:005942-0187
Journal Information:
AAPG Bulletin, Vol. 79, Issue 8; Conference: International conference and exhibition of the American Association of Petroleum Geologists, Inc.: managing change at the turn of the century, Nice (France), 10-13 Sep 1995; Other Information: PBD: Aug 1995
Country of Publication:
United States
Language:
English