By M. Y. Ali
Somaliland (Northern Somalia) is situated on the northern side of the Horn of Africa with the Gulf of Aden to the north, Somalia to the east, Ethiopia to the south and west, and Djibouti to the north-west (Fig.1). The morphology of the country is typical of areas in extension, with basins and mountains of up to 2000 m. There is little folding, but much normal faulting, some of which has very great throws. These strong vertical movements have controlled the accommodation space available for sediment deposition since the Lower Jurassic.
To date, there have only been 21 wells drilled in Somaliland (19 onshore and two offshore), many of which were only stratigraphic tests (Fig. 2). In fact, few of the wells evaluated the hydrocarbon potential of the country and the type of prospects in the drilled basins. In addition, modern seismic reflection surveying has had very limited application in Somaliland. Therefore, many prospective petroleum systems in the onshore and offshore regions of the country remain relatively unexplored.
In this paper, seismic, well, and outcrop data have been used to determine the petroleum systems of Somaliland. These data demonstrate that the country has favorable stratigraphy, structure, oil shows, and hydrocarbon source rocks. In addition, the results show that the Upper Jurassic and Cretaceous units, and possibly Oligocene-Miocene units, show potential for hydrocarbon generation. Traps are provided by rollover anticlines associated with listric growth faults and rotated basement faults which are controlled by Upper Jurassic to Lower Cretaceous tensional stresses.