阿尔金山南缘吐拉盆地侏罗系砂岩成岩作用研究

Diagenesis of the Jurassic Sandstone in the South to the Altyn Tagh

在大量岩石学和铸体薄片研究的基础上，运用Ｘ衍射等分析手段，对吐拉盆地嘎斯煤矿附近侏罗系地层中砂岩的成岩作用、孔隙演化及成岩阶段等特征作了详细研究，认为孔隙的发育既受沉积条件控制，又受埋藏成岩作用的影响。机械压实作用是导致砂岩孔隙结构变差的主要因素；早期碳酸盐胶结作用弱，使得后期的溶解改造作用也较弱；造成了砂岩的有效储集空间较差的结果。构造作用使得岩石中裂隙发育，提高了岩石孔渗性，极大地改善了岩石的储集性能，形成了较好的储层。

With numerous observations of thin sections and casting sections of the rocks,an d the application of various analytical techniques including X ray diffraction, the main diagenesis,pore evolution and the characteristics of diagenetic sequenc e in the Jurassic reservoir sandstone in Tula Basin,southern Altyn Tagh,Xinjiang ,are carefully studied.It is concluded that the pore evolution is both controlle d by depositional conditions and affected by burial diagenesis.Compaction is the major factors turning the pore texture of the sandstone worse.Cementation of th e carbonate is very weak in the early diagenesis period,and this make the disso lution weak too.The strong compaction and weak cementation are of importance tha t form the result of the worse reservoir space.Modified by tectonics,the clasti c rocks became the better reservoir of oil and gas with its high porosity and pe rmeability in the Tula Basin.