Hydrocarbon
Potential of the
El-Mowafy, Hamed Zeidan1, Paul Mann2, Alejandro
Escalona2 (1) Institute for Geophysics, Jackson School of
Geosciences, University of Texas at Austin, Austin, TX (2) Jackson School of
Geosciences, The University of Texas at Austin, Austin, TX
Although
We use a 885 km
grid of 2D seismic data and three deep exploration wells drilled in 1989/90 to
evaluate the hydrocarbon potential of two, 5.4-6 km-thick offshore basins near
Four seismic sequences are defined:
Sequence 1 consists of a 1300-m-thick section of continentally-derived clastic deep-water sediments, overlying an irregular
basement of Late Cretaceous-Paleogene arc rocks;
thicknesses are controlled by an east-striking set of parallel normal faults.
Sequence 2 consists of a 2600-m-thick, early Miocene section of deep-marine
deposits controlled by northwest-striking normal faults; the top of sequence 2
corresponds to the Middle Miocene unconformity of regional extent. Sequences 3
and 4 record 1450-m of a late Miocene deepwater to shelfal
clastic and carbonate basin section; shelf-slope-fan clastic systems infill from small deltaic systems along the
Venezuelan coast; normal displacements are observed on a set of
northwest-striking faults.
Limited maturation data from the three
wells indicates that only the southwestern part of the study area falls within
the oil and gas window. These observations are consistent with bright spots
seen on the seismic data and by gas shows reported from the wells.
A potential source is the
continentally-derived terrigenous section of sequence
1; potential reservoirs include slope fans within sequence 3 and carbonate
buildups on footwall blocks within sequence 4. Migration pathways are provided
by northwest-striking normal faults that penetrate from the basement level
through sequence 4.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California