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

Journal Article · · Am. Assoc. Pet. Geol. Bull.; (United States)
OSTI ID:6150234
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), Journal Name: Am. Assoc. Pet. Geol. Bull.; (United States) Vol. 65:6; ISSN AAPGB
Country of Publication:
United States
Language:
English

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