Abstract:

Given the shortage  of core and mud logging data on the Д zone of Carboniferous KT-II of the southern of Д area in the eastern edge of Pre-Caspin basin, The oolitic dolomitic limestone on the lower of Д₁ layer was defined as favorable reservoir layer in Carboniferous KT-II by the detailed analysis on borehole data in the southern of Д area in the eastern margin of Pre-Caspin basin. This favorable reservoir in Д₁ layer are pore-vug-fracture composite and pore-fracture. The favorable sedimentary facies belt with beach miscorfacies of shoal subfacies in open platform facies is determined combined with the paleostructure and sedimentary facies. The carbonate rock reservoir in Д₁ layer was controlled with both original depositional environments and dolomitization. Based on the sedimentary facies constraints and the optional seismic attributes selection with the pre-stack and post stack inversion, the advantageous reservoirs distribution with NE-SW belts on Д₁ layer is predicted considering the thickness, porosity, fracture and hydrocarbon indicator on carbonate rock reservoir.All these provide the effective and prospective geological references for drilling and production for KT-II.

Key words: carbonate reservoir, Carboniferous, reservoir, Caspian basin