Gas Shale Reservoir Characterization: A North Africa Case

Abstract

Abstract In the last period with the rising price of oil and gas, the exploration and development of unconventional plays, that are already an economic reality in North America, are gaining more attention worldwide. It is common opinion that Gas Shale reservoirs are not peculiar only to the North America Basins. ENI E&P has focused attention on this type of unconventional reservoir, both in new countries and in the areas where it has historically been successful in conventional plays and where large amount of data are available. New wells drilled in North Africa, planned to discover conventional hydrocarbon-bearing sandstone layers in the Silurian and Ordovician formations, have also been used to characterize in detail the Silurian Hot Shale that was normally interpreted as source rock. A dedicated data acquisition strategy was planned (logs and core) and, consequently, interpretation was carried out with the specific aim of characterizing this unconventional Gas Shale reservoir. This paper documents the workflow used to characterize this unconventional reservoir. It will examine in detail the wireline log interpretation based on integration with the experimental data from core. A robust characterization of a gas shale reservoir basically starts from core analysis (geochemical, petrographical, mineralogical and petrophysical) that are used for calibration and integrated in the wireline log interpretation. The benefits of these results will provide better evaluation of the hydrocarbon potential of Hot Shale in this area.