ANALYSIS OF PETROLEUM GEOLOGICAL CONDITIONS OF THE GUERARA BLOCK IN THE TRIASSIC BASIN, ALGERIA

The Guerara block is located in the north of Triassic Basin which is rich in oil and gas resources with its original hydrocarbon accumulations accounting for 70% of Algeria.The main reservoir type is composite reservoir which are lithologic,stratigraphic pitch-out and anticline hydrocarbon reservoirs.In the study area,the main source rocks are Silurian marine mudstone and the secondary is Ordovician mudstone.The main reservoir rock is Triassic sandstone and the secondary is Ordovician and Cambrian quartz sandstone.The structural traps is mainly anticline with low amplitude.Based on the research of basic accumulation geological conditions,it shows that the occurrence of Silurian hydrocarbon source rocks and petrophysics properties of reservoir are controlling factors of reservoir distribution.The Hercynian unconformity surface and its sandstone in the upper and lower provide the pathway for lateral migation of oil and gas.North-east trending fault and its associated micro-fractures provide the pathway for the vertical migration of oil and gas.The traps-growing belts in Argoub and Bouaicha are selected favorably for breakthrough of future exploration.