The Research Of Characteristics And Its Controlling Factors Of Sandstone Reservoir Lithogenous Phase Of Taiyuan-Shanxi Formation In Daning-Jixian Area

The sandstone reservoir of Taiyuan-Shanxi formation in Daning-Jixian area had three kinds of lithogenous phase:(1)Lithic sandstone-dissolved pore-intercrystalline pores-argillaceous cement phase;(2)Lithic quartz sandstone-intergranular pore-dissolved pore-siliceous-argillaceous cement phase;(3)Quartz sandstone-intergranular pore-intercrystalline pore-siliceous cement phase.Shanxi Formation sandstone reservoirs mainly developed the former two types and Taiyuan Formation mainly developed quartz sandstone-intergranular pore-intercrystalline pore-siliceous cement phase.In above three types of lithogenous phase,Quartz sandstone-intergranular pore-intercrystalline pore-siliceous cement phase developed the best porosity zone because of its high quarts contends and low shale contends which make the rock had excellent anti-compact abilities.What's more,Lithic quartz sandstone-intergranular pore-dissolved pore-siliceous-argillaceous cement phase had secondary good porosity and the reservoir of Lithic sandstone-dissolved pore-intercrystalline pores-argillaceous cement phase didn't grow well.The lithogenous phase of target area is mainly controlled by mineral composition,structure and sedimentary environment.Mineral structure is the most important effect in influencing factors of Quartz sandstone-intergranular pore-intercrystalline pore-siliceous cement phase.Porosities and particle sorting was positively correlated.While Lithic sandstone-dissolved pore-intercrystalline pores-argillaceous cement phase and Lithic quartz sandstone-intergranular pore-dissolved pore-siliceous-argillaceous cement phase are mainly affected by content of quartz and the type of cement.The sedimentary environment of Taiyuan formation was mostly tidal channel so that rocks under this environment were not easy to be damaged by diagenesis.Therefore this is the most beneficial advantages lithogenous phase.As delta front is the main depositional environment of Shanxi formation,shale content of rock is high,in the mean time,small particle,general sorting and high contend of shale make rock more susceptible to late diagenetic and makes the reservoir more easy to be damaged.Comparably the estuary dam micro-phase is the advantage environment to develop beneficial lithogenous phase of Shanxi formation.