Lowstand Systems Tract Identification and Prospectivity in Southern Red Sea
By
Mohammad I. Faqira1
(1) Saudi Aramco, Dhahran, Saudi Arabia
Seismic characters of Maqna2 Formation show lowstand systems tract
geometries in southern Red Sea. Several seismic criteria such as geometries,
patterns, and attributes have been observed within Maqna2 seismic facies. The
slope fan seismic facies is a text-book example in this area, deep marine fan
and low standwedge were interpreted relative to it. This seismic facies
characterized in strike direction by mounded shape, convex upward reflection
pattern with bi-directional downlap, common occurrence of high amplitude
reflection on the upper surfaces due to the velocity contrast between
the
basinal shale-prone sediments and the underlying middle and/or lower fan
sand-prone sediments, three dimensional fan shape, velocity pull-up for the
underlying sediments due to the difference in velocity
between
the slope fan
sands and in
between
shale-prone lowstand wedge, and finally the differential
compaction
between
the sand-prone mounds and the adjacent the shale-prone
sediments which cause drape of the overlying sediments across the fan edges. The
low stand wedge shows onlap
relation
on the older slope fan filling the area’s
between
the fans. On dip direction these lowstand sub marine fans demonstrate
shingled progradational clinoform pattern, which indicate a shallow water
prograding system, deep marine fan shows low relief bi-directional mound basin
word from the slope fan which downlap onto it, and lowstand wedge onlaps onto
the slope fan with retro-gradational pattern. The slope marine fans
characterized by thin turbidite sands, with poor reservoir properties. These
lowstand systems tract have significant structural and stratigraphic exploration
potential.