That's a lie, go look at seismic testing done by range resources in Puntland and why they left.
The North and South have a different continental shelf, which extends from Kismayo to Mudug. This is confirmed by tests done by Spectrum Geo
Southern and Central Somalia
The seismic data reveals several large fold and thrust belts including a predominantly Tertiary fold belt, similar to offshore Mozambique in the Rovuma Basin. There is also an older Cretaceous fold belt involving Cenomanian to Maastrichtian shelf and slope sediments that have been thrust up and folded into a plethora of large anticline structures.
The interesting thing about this fold belt is that all the thrust planes sole-out on a common detachment surface that we interpret to be Cenomanian–Turonian (CT) shales. It is well known that shales rich in organic carbon, and particularly those in the oil window, can act as regional detachment surfaces. The model predicts that the shales that act as slip surfaces for the thrusts can also be the source rock that supplies the oil to the overlying structures.
The probability of finding good quality reservoirs is high. Thick, quartz-rich sandstones of Cretaceous and Tertiary age with high porosity are expected in the southern and central Somalia basins as a result of erosion from largely Precambrian granitic basement plus reworking of older Karoo sandstones. The burial depths are not high, so we expect good porosity to be maintained.
Northern Somalia
The northern part of offshore Somalia has a very different geology to that found to the south. The reason for this is related to the creation of a huge uplifted structural arch, known as the Somalia Arch, at the start of the Late Cretaceous
US exploration blocks and basins pre-1991 collapse.