Lower Cretaceous Cogolla Group, Maracaibo Basin, Venezuela: sedimentology, diagenesis, and petrophysics

Journal Article · Mon Jun 01 00:00:00 EDT 1981 · Am. Assoc. Pet. Geol. Bull.; (United States)

OSTI ID:6150234

Bartok, P ^[1]; Reijers, T J.A.; Juhasz, I

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1. Maraven S.A., Caracas, Venezuela

The Cogollo Group, consisting mainly of carbonates, was deposited over a broad and irregular stable shelf. High-energy, shallow, normal-marine environments are represented by grainstone/packstone bars, interbar deposits, and pelecypod biostromes. Low-energy, restricted, shallow-marine environments are shown by back-bar to tidal-flat deposits including lagoonal sediments rich in organic matter, shales, and glauconitic and quartzitic sandstones. Diagenetic processes were ongoing during hydrocarbon migration. Thus the modest texture-related reservoir space in the carbonates was, and still is, able to store the oil. Local fractures and leached intervals in the carbonates allow oil to drain and be produced. Thus, fractures form a significant element in Cogollo production capacity. (JMT)

• OSTI ID: 6150234
• Journal Information: Am. Assoc. Pet. Geol. Bull.; (United States), Vol. 65:6
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
CARBONATE ROCKS
DEPOSITION
DIAGENESIS
PETROLEUM DEPOSITS
VENEZUELA
CRETACEOUS PERIOD
FRACTURES
GEOLOGIC FISSURES
PETROLEUM GEOLOGY
SEDIMENTATION
DEVELOPING COUNTRIES
FAILURES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOLOGY
LATIN AMERICA
MESOZOIC ERA
MINERAL RESOURCES
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SOUTH AMERICA
020200* - Petroleum- Reserves
Geology
& Exploration