A Field study report to the Albertine Graben area, Western Uganda.

Abstract

The Basin of semliki is covered by sediments that represent the Middle Miocene to recent, which are described from outcrop and well data, underlain by possible Jurassic or Permo-Triassic to Early Tertiary sediments which rest unconformable on Basement, described from seismic data. Sediments in Semliki Basin are predominantly composed of sandstones, siltstones and claystones while the basement rocks consist of high grade metamorphic and igneous rocks such as granite, granite gneiss, amphibolite and quartz veins and the study has allowed a better understanding of the stratigraphic relationship of the different rock units that are exposed on outcrops, those encountered in the wells, a section interpreted from seismic data. The depositional environment of the sediments in the Semliki Basin is fluvial-lacustrine/deltaic showing significant variations in gamma ray character, which reflect the water-level changes and river interactions through the depositional period and the influence of rifting tectonics on sediment deposition through time and space. The surface manifestation of Sempaya Hotspring is evident for the early maturation of the organic matter to expel Oil in the young sediments of Albertine Graben. The sediments in the Semliki Basin represents petroleum play for hydrocarbon accumulations, in which the necessary elements of a valid petroleum systems were identified. These include excellent or good potential for reservoir and seal as well as circumstantial evidence of regionally mature source rocks, possible seals, traps and hydrocarbon-migration pathways.