Carbonate lithofacies, diagenesis, porosity relationships and crude oil geochemistry, Ratawi Formation, Kuwait-Saudi Arabia divided neutral zone
The Neocomian Ratawi Formation, in Kuwait-Saudia Arabia Divided Neutral Zone, is divided into six lithologic facies: algal wackestone (Ia), skeletal wackestone/packstone (Ib), algal boundstone (IIa), biopelpackstone/grainstone (IIb), oobiopelgrainstone (IIc), and planktonic-fossil assemblage indicate a shallow, open normal marine environment. Intermicrite porosity is the dominant porosity in Wafra, Hout and Dorra fields (70-90% of the total 20%) while biomoldic porosity is dominant in Khafji area. The Wafra limestone is interrupted by a long interval of clay invasion which deposited shale/limestone intercalation in the subtidal environment. The total thickness of the boundstone facies ranges from 50-100 feet in Wafra and Khafji to 20 feet in Dorra. The oil was accumulated in three major types of voids; intergranular, biomoldic, and interframe porosities. The biopelpackstone/grainstone (IIb) facies occurs as thick beds in Wafra and Khafji limestones and decreases abruptly in the Hout and Dorra areas. This facies indicates a subtidal/shelf edge depositional environment. This facies exhibits the highest effective porosity (up to 30%), where the dominant biomoldic and intergranular porosities are filled partially with dead oil. The oobiopelgrainstone was confirmed only in the Wafra area where it reaches a thickness of 150 feet. It is composed mainly of coated bioclastic fragments, which indicate an outer shelf depositional environment. The porosity is predominantly intergranular (12-18%) and is filled with oil.
- Research Organization:
- Texas Tech Univ., Lubbock, TX (USA)
- OSTI ID:
- 7017931
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
KUWAIT
PETROLEUM DEPOSITS
GEOLOGY
SAUDI ARABIA
ALGAE
CLAYS
DEPOSITION
DIAGENESIS
GEOCHEMISTRY
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOLOGIC TRAPS
LIMESTONE
LITHOLOGY
OIL SATURATION
PETROLEUM
POROSITY
RESERVOIR ROCK
SEDIMENTATION
SHALES
THICKNESS
ASIA
CARBONATE ROCKS
CHEMISTRY
DIMENSIONS
ENERGY SOURCES
FOSSIL FUELS
FUELS
GEOLOGIC DEPOSITS
MIDDLE EAST
MINERAL RESOURCES
PLANTS
RESOURCES
ROCKS
SATURATION
SEDIMENTARY ROCKS
020200* - Petroleum- Reserves
Geology
& Exploration