Micro-pore Structure of Tight Sandstone Reservoir and Influence on Reservoir Physical Properties:Chang 6 Member of Huangling Area,Ordos Basin as an Example
The reservoir space and pore structure of Chang 6 Member tight sandstone in Huangling area of Ordos Basin were characterized by using core,thin slice and pore image,scanning electron microscope and high pressure mercury injection data,and their influence on reservoir properties was analyzed.The results show that residual intergranular pores,feldspar pores,intergranular pores and microfractures are the main reservoir spaces in this study area.The average porosity and permeability of Chang 6 Member are 7.46％and 0.32 mD respectively.The radius distribution range of pore throat was 0.150 μm to 2.597 μm,showing unimodal and bimodal distribution,and the radius of main throat was 0.148 μm to 0.760 μm.In tight sandstone reservoirs,large pore throat corresponding pore contributes 10％～30％to permeability,and that of medium and small pore throats accounted for 17％to 53％,which are the main contributions to the permeability of the reservoir,while the nano-pore throat accounts for 35％～67％,which basically has no contribution to the permeability,but has contribution and influence on the porosity.The permeability heterogeneity is mainly caused by the pores corresponding to the radius of the large pore throat,and the porosity heterogeneity is mainly caused by the pores corresponding to the small pore throat.For reservoirs with permeability greater than 0.1 mD,pore throat radius greater than 0.5 μm is the main cause of permeability heterogeneity.
pore structurereservoir propertiestight sandstone reservoirYanchang formationChang 6 member
万方数据
维普
