摘要

Organic geochemistry analysis and formation fluid overpressure study have been performed on several oil well data located to the northern part of the Ghadames Basin (southern Tunisia Saharan platform). The main results of this work highlight the important role of overpressured interval in hydrocarbon accumulation. In fact, the analysis of the Paleozoic-Mesozoic petroleum systems in Southern Tunisia shows that the hydrocarbons generated by Ordovician and Silurian source rocks migrate upward following fault systems or through the major Hercynian unconformity to finally accumulates in structural or stratigraphic traps. These migration pathways provide favorable conditions to fill up the Silurian, Devonian, or Triassic reservoirs. The overpressured zone located above Triassic reservoir constitutes a continuous and efficient seal to hydrocarbon trap structures. So the overpressure plays the role of hydraulic seal advantaging oil and gas accumulation in the Ghadames Basin associated with the impermeable (evaporites) and then stopping any upward migration of natural hydrocarbon.

  • 出版日期2012-7