Li̇thology and Oi̇l-Gas Content of the Producti̇ve Seri̇es Sedi̇ments of the Southwest Part of the Absheron Oi̇l-Gas-Beari̇ng Regi̇on

The study areas are located in the south-west of Absheron oil-gas-bearing region. The main oil and gas resources in this region are associated with Productive series sediments of Lower Pliocene system. The comparison of sediments and lithofacies of the Lower Productive series have been studied within Bibiheybat, Bahar, Gum-deniz areas of the South Absheron zone in the article. The thickness of PS sediments is thiker in the study area. Lithologically, the Productive series sediments are represented by the alternation of sandy-aleourolite-clayey rocks. Lower Pliocene sediments have undergone significant changes in their lithofacies, both at depth and along area. An increase in sand content is observed in the PS section from west to east in the Absheron oil-gas-bearing region.The variation of thicknesses, sand and clay content in Bibiheybat, Gum-deniz and Bahar fields was determined. The changes in reservoir characteristics of PS suites in Bibiheybat, Gum-deniz and Bahar fields were analyzed. The analysis of porosity, permeability and carbonate in the studied areas of the PS suites suggests that in the Bibiheybat area, a regularity between carbonate and porosity and permeability is followed at depth towards the Pre-Kirmaki suite, so, carbonate decreases, porosity and permeability increases. However, the against regulation is observed in GaS, so carbonate increases, porosity and permeability decrease. Along the Gum-deniz area, porosity and permeability decrease with the increase of carbonate towards the GaS. In the Bahar field, the decrease of carbonate toward GaS, on the conrtary, the increasing of porosity and permeability is observed. The comparative analysis of the reservoir properties along the fields suggest that the suites of the PS from the Bahar field to the Bibiheybat field are characterized by high reservoir properties. This is suggesting the prospect of oil-gas-bearing of lower suites of PS. Keywords: Bibiheybat field, Productive series, oil-bearing, lithology, porosity, permeability, carbonate, sandiness, clayey.