A Report on the Geologic and Stratigic logging Project of Semliki Basin - Albertine Graben in Ntoroko District Western Uganda.

Abstract

From10th July-20nd July 2023, a field work and excursion study to the Albertine graben was conducted by petroleum geology students. The study area was the Semliki basin, which is in Uganda's southern Albertine Graben. It is located south of Lake Albert, and it is bordered to the east and south by escarpments and to the west by the river Semliki. . It is a pull apart basin formed when the Albertine graben, a product of active rifting, underwent transtensional strike-slip deformation that was controlled by already existing NE-SW in the graben forming normal faults. With the help of our lectures during this study, we were able to practically understand the region's geology and analyse its petroleum system using the geological, geophysical, and other skills we had learned during the study. Through careful investigation of the stratigraphy and sedimentary structures, environments of deposition as well as the depositional processes that occurred in the region were inferred during the field work studies. Stereographic analysis and stratigraphic log interpretation helped to further substantiate this.

The area's diverse facies types were identified along with their importance in the formation of quality reservoir rocks and seals. Facies analysis was used to determine the Semliki basin's genesis and petroleum potential. According to the interpreted seismic sections, the basin was subjected to intense tectonic activity, which caused the construction of a wide variety of structures within the sediments and basement. Hot springs in the vicinity showed that there were sufficient temperature gradients for accelerated oil maturation.

The sediments were thick enough and were made up of alternating layers of thick sandstones over laid by clays, according to the geophysical logs from the Turaco well that were analyzed.