Facies control on oil producing, naturally fractured reservoirs, a cast study: Block I, Lake Maracaibo, Venezuela

Conference · Mon Feb 01 04:00:00 EST 1988 · AAPG Bull.; (United States)

OSTI ID:5793846

Rodriguez, A; Marquez, X

In Block I, Lake Maracaibo, oil producing intervals in the Cretaceous have been found to be facies controlled. Detailed studies of the cored sections in various wells have shown that facies Ls2, characterized by an oolitic grainstone, is the main producing reservoir. This facies has been interpreted as deposited as an oolitic shoal in a shallowing-upward sequence. Other facies such as Ls1, represented by a bioclastic rudstone, and Ls, composed of a mudstone, are also present but do not show significant oil production. The presence of subvertical, open, hairline fractures and centimeter-scaled wide, bridged fractures in facies Ls2 can explain its great producing capacity, while the presence of calcite mineralized fractures in Ls1 and absence of fractures in Ls account for the poor producing capability of these facies. In contrast to what has been reported in other case studies, the grainstone facies shows the most fracture density and open fractures. A facies model which predicts the lateral continuity of the facies present in Block I is proposed as a tool for oil exploration and exploitation for this area and other areas with similar sedimentological characteristics.

• Research Organization: Maraven S.A., Caracas (Venezuela)
• OSTI ID: 5793846
• Report Number(s): CONF-880301-
• Conference Information: Journal Name: AAPG Bull.; (United States) Journal Volume: 72:2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
CRETACEOUS PERIOD
DEVELOPING COUNTRIES
EXPLORATION
FRACTURED RESERVOIRS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC TRAPS
LATIN AMERICA
MESOZOIC ERA
MINERAL RESOURCES
PETROLEUM DEPOSITS
RESERVOIR ROCK
RESOURCES
SOUTH AMERICA
VENEZUELA