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.