Distribution Rule And Formation Mechanism Of Gas And Water In The Second Member Of Shanxi Formation Of Lower Permian In Zhizhou Area In Ordos Basin

The paper research Shan-2 members distribution of the sand-body and feature of reservoir. Based on the study of discrimination of single well pay zones and reservoir fluid;on the base of gas-water profile to study distribution characteristics of research area and find distribution law and controlling factors in research area;with data of hydrochemical water oformation water and forecast gas and water distribution.At the sanme tiime ,we point out favorable exploration targets. Results was:1. At the bottom of Shan-2 members of sandbody steady,middle-head of sandbody don't steady and connectivity sandbody along river channel was well. Shan-2 members reservoir is belong to low porosity and permeability; pore types main intergranular pore and intergranular dissolved pores and the pore structure was well. reservoir were mainly composed of type II ,type III were development. Reservoir conduct intensely leterogeneity in. plane and internal.2. Shan-2 members formation water is type V of CaCl₂ and is belong to residual waterr in formation.we identify two type of formation :water in lenticular,edge and bottom water. Degree of mineralization of water in lenticular is lower and main cation is Na⁺; degree of mineralization edge and bottom water is high and main cation is Ca²⁺,two type of formation water have different factor.3. Distribution of edge (bottom) water was controled structure and sedimentary facies characteristics; SW inclined structure and sedimentary facies Tract in NS,so south and southwest of three sandbody lower location of the structure being edge and bottom water.While per area is not unite gas/water surface and gas/water surface differed 300m from west to east.The appearance illustrate:Zi-Zhou gas pol of Shan-2 members is not a unite and it is combined by many independence gas pol. 4. Distribution of lenticular wate was contrled by reservoir characteristics and process of hydrocarbon accumulation. Because early diagenetic stage of tightening and heterogeneity,being of a low gas filling and high water saturation in Shan-2 members.In gas area, capillary pressure of type III,IV is high and gas displace formation water incompletely or don't displace formation water.The appearance result formation water(water in lenticular) enrichment in Shan-2 members. Shan-2 members absent water over gas phenomenon and the type of gas pool is belong to structure-lithostratigraphic gas reservoirs.5. Research result demonstrate::thicker sandbody,well reservoir properties,far away gas/water surface near yu 48 is the advantageous exploration area; gas area range of yu 69 and yu 29 was small and oil-gas exploration is hard.