skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The Boscan Field-Venezuela's giant stratigraphic trap with a complex history

Abstract

The Boscan Field lies in the northwest quadrant of the Maracaibo Basin, Venezuela. It is a large stratigraphic trap that has produced more than 800 million barrels of heavy oil since 1946, principally from Eocene fluvial-deltaic clastic reservoirs. These are faulted, folded, and are truncated by a pre-Oligocene unconformity. The geochronology of the Boscan Field has been interpreted as follows: (1) Eocene fluvial-deltaic deposits prograded east and southeast across the Boscan Field Area. A subsiding area northeast towards the State of Falcon received tremendous quantities of Eocene fine grained organic-rich deposits in pro-delta and deep water environments. (2) The Eocene shales in the deep basin began to generate hydrocarbons which migrated towards the west and southwest. (3) In the Boscan Area, Eocene deposits were folded, faulted, and tilted towards the east and southeast and an active fluvial flood-plain truncated the deposits resulting in subcrop bands that form the pre-Oligocene unconformity topographic surface. (4) Hydrocarbon generation and migration continues in the deep basin. (5) Oligocene fluvial sandstones deposited on the underlying unconformity often cut into and are in direct contact with truncated Eocene sandstones. This allowed some oil to leak up into the Oligocene deposits. (6) By the end of themore » Oligocene, migration of oil into the gross Boscan trap was well underway. The east-west and northwest southeast trending fluvial conduits carried the oil out of the Eocene basin northwestward until it was blocked by reservoir truncation on the west and northwest sides of the Boscan Field. (7) Regional subsidence of the Maracaibo Basin has caused the Boscan reservoirs to dip towards the southwest resulting in realignment of fluids. The present-day Boscan Field is a composite of stacked, linear, faulted, and truncated reservoir segments. They may be isolated or interactive with other segments and form a complex [open quotes]plumbing[close quotes] tangle.« less

Authors:
 [1]; ; ; ; ; ;  [2]
  1. Swanson Consulting Services, Houston, TX (United States)
  2. Corpoven S.A., Caracas (Venezuela)
Publication Date:
OSTI Identifier:
5939097
Report Number(s):
CONF-930306-
Journal ID: ISSN 0149-1423; CODEN: AABUD2
Resource Type:
Conference
Journal Name:
AAPG Bulletin (American Association of Petroleum Geologists); (United States)
Additional Journal Information:
Journal Volume: 77:2; Conference: International congress of the American Association of Petroleum Geologists (AAPG), Caracas (Venezuela), 14-17 Mar 1993; Journal ID: ISSN 0149-1423
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; 58 GEOSCIENCES; GEOLOGIC STRUCTURES; ORIGIN; GEOLOGIC TRAPS; STRATIGRAPHY; OIL FIELDS; GEOLOGIC HISTORY; VENEZUELA; PETROLEUM GEOLOGY; EOCENE EPOCH; GEOLOGIC FAULTS; HYDROCARBONS; MIGRATION; ORIENTATION; RESERVOIR ROCK; RIVER DELTAS; SANDSTONES; SHALES; SOURCE ROCKS; CENOZOIC ERA; COASTAL REGIONS; DEVELOPING COUNTRIES; GEOLOGIC AGES; GEOLOGIC DEPOSITS; GEOLOGIC FRACTURES; GEOLOGY; LATIN AMERICA; MINERAL RESOURCES; ORGANIC COMPOUNDS; PETROLEUM DEPOSITS; RESOURCES; ROCKS; SEDIMENTARY ROCKS; SOUTH AMERICA; TERTIARY PERIOD; 020200* - Petroleum- Reserves, Geology, & Exploration; 580000 - Geosciences

Citation Formats

Swanson, D C, Jaimes, J, Valdez, C, Pirela, B, Puche, F, Rojas, D, and Moya, E. The Boscan Field-Venezuela's giant stratigraphic trap with a complex history. United States: N. p., 1993. Web.
Swanson, D C, Jaimes, J, Valdez, C, Pirela, B, Puche, F, Rojas, D, & Moya, E. The Boscan Field-Venezuela's giant stratigraphic trap with a complex history. United States.
Swanson, D C, Jaimes, J, Valdez, C, Pirela, B, Puche, F, Rojas, D, and Moya, E. 1993. "The Boscan Field-Venezuela's giant stratigraphic trap with a complex history". United States.
@article{osti_5939097,
title = {The Boscan Field-Venezuela's giant stratigraphic trap with a complex history},
author = {Swanson, D C and Jaimes, J and Valdez, C and Pirela, B and Puche, F and Rojas, D and Moya, E},
abstractNote = {The Boscan Field lies in the northwest quadrant of the Maracaibo Basin, Venezuela. It is a large stratigraphic trap that has produced more than 800 million barrels of heavy oil since 1946, principally from Eocene fluvial-deltaic clastic reservoirs. These are faulted, folded, and are truncated by a pre-Oligocene unconformity. The geochronology of the Boscan Field has been interpreted as follows: (1) Eocene fluvial-deltaic deposits prograded east and southeast across the Boscan Field Area. A subsiding area northeast towards the State of Falcon received tremendous quantities of Eocene fine grained organic-rich deposits in pro-delta and deep water environments. (2) The Eocene shales in the deep basin began to generate hydrocarbons which migrated towards the west and southwest. (3) In the Boscan Area, Eocene deposits were folded, faulted, and tilted towards the east and southeast and an active fluvial flood-plain truncated the deposits resulting in subcrop bands that form the pre-Oligocene unconformity topographic surface. (4) Hydrocarbon generation and migration continues in the deep basin. (5) Oligocene fluvial sandstones deposited on the underlying unconformity often cut into and are in direct contact with truncated Eocene sandstones. This allowed some oil to leak up into the Oligocene deposits. (6) By the end of the Oligocene, migration of oil into the gross Boscan trap was well underway. The east-west and northwest southeast trending fluvial conduits carried the oil out of the Eocene basin northwestward until it was blocked by reservoir truncation on the west and northwest sides of the Boscan Field. (7) Regional subsidence of the Maracaibo Basin has caused the Boscan reservoirs to dip towards the southwest resulting in realignment of fluids. The present-day Boscan Field is a composite of stacked, linear, faulted, and truncated reservoir segments. They may be isolated or interactive with other segments and form a complex [open quotes]plumbing[close quotes] tangle.},
doi = {},
url = {https://www.osti.gov/biblio/5939097}, journal = {AAPG Bulletin (American Association of Petroleum Geologists); (United States)},
issn = {0149-1423},
number = ,
volume = 77:2,
place = {United States},
year = {Mon Feb 01 00:00:00 EST 1993},
month = {Mon Feb 01 00:00:00 EST 1993}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: