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四川西部新场上侏罗统蓬莱镇组储层物性和孔隙结构与低孔渗的上三叠统—中侏罗统致密砂岩比较，其储集条件明显变好，孔隙度一般为１５％～１８％，平均渗透率３６３×１０－３μｍ２，属致密型向常规型过渡的储层类型。储层砂体厚度自西向东有增厚的趋势，储集性也逐渐变好，但总体差异不大；有四种基本孔隙类型，孔隙宽度服从正态分布；从Ⅰ类储集岩到Ⅳ类储集岩，孔隙结构由好变坏、毛细管压力由粗歪度变为细歪度、排驱压力和饱和度中值压力由小变大、孔喉半径依次变小、储渗性依次下降，直至变为非储集岩。储渗性主要受方解石含量和粘土矿物产状的影响。

RESERVOIR CHARACTERISTICS OF THE UPPER MEMBER OF PENGLAIZHEN FORMATION AT XINCHANG IN WEST SICHUAN

??The petrophysical property and pore structure of the reservoirs in Penglaizhen Formation of Upper Jurassic at Xinchang in West Sichuan is obviously better than the tight sandstone with low porosity and low permeability of Upper Triassic Middle Jurassic,the porosities being generally 15%??18%,the average permeability being 3.63×10^-3 ??m²,belonging to a transitional category of reservoir from a tight type to a conventional one.The thickness of reservoir sand body tends to increase from the west to the east and its petrophysical property gets better gradually,but the difference is finite on the whole.Four basic types of pores are found and the pore widths obey normal distribution.From Type-?? reservoir to Type-?? reservoir,the good pore structure is changed into the bad one,the capillary pressure curve with bold skewness into that with gentle skewness,the small displacement pressure and saturation mid value pressure are changed into the large ones,the pore throat radii become small successively and the storage property and permeability are uninterruptedly reduced till the reservoir rock is changed into the non-reservoir one.The storage property and permeability are mainly affected by the calcite content and clay mineral occurrence.