Abstract: Tertiary reservoir rocks in western part of south margin of the Junggar basin are mainlysandstones and sandy conglomerates.The reservoir in Shawan formation rocks are braidedchannel sandbodies with median porosity and low permeability.Those in the Taxihe forma-tion are coastal bars which are characterized by high porosity and high permeability-lowporosity.However,the Shawan and and Taxihe formations are the favorable reservoirs in theDushanzi oil field.The main factor affecting the reservoirs is the content of cement.The existence of largeamount of montmorillonite and illiteresulting in particle migration and blocking of the porespace.Meanwhile,later calcite cernentation make reservoir rocks more compact,reducingporosity and permeability.Petrophysical properties is depend on the amount of calcite,andthe degree of the damaged reservoir depends on the content of montmorillonite.

Key words: Junggar basin, Tertiary, reservotr characteristics, cementation, nalysis, evaluation

摘要： 准噶尔盆地南缘西部第三系储层以砂岩、砂砾岩为主.沙湾组属辫状河道砂体,储集物性较差,具有中孔、低渗的特点.塔西河组属沿岸砂坝,储集物性好至差,具高孔高渗至低孔低渗的特点,两极分化严重.独山子油田沙湾组、塔西河组,是目前盆地南缘发现最好的含油气储层.影响储层主要因素是胶结物含量.大量蒙脱石、伊/蒙混层粘土矿物的存在,造成微粒运移堵塞了粒间孔隙.晚期方解石的胶结,致使岩性致密,孔隙度变小,渗透性变差.方解石含量的多少,决定着储层物性的好坏;蒙脱石含量的高低,决定着油层的损害程度.

关键词: 准噶尔盆地, 第三系, 储集层特征, 胶结作用, 分析, 评价