Abstract: With numerous observations of thin sections and casting sections of the rocks, and the application of various analytical techniques including X ray diffraction, the main diagenesis, pore evolution and the characteristics of diagenetic sequence in the Jurassic reservoir sandstone in Tula Basin, southern Altyn Tagh, Xinjiang, are carefully studied. It is concluded that the pore evolution is both controlled by depositional conditions and affected by burial diagenesis. Compaction is the major factors turning the pore texture of the sandstone worse. Cementation of the carbonate is very weak in the early diagenesis period, and this make the dissolution weak too. The strong compaction and weak cementation are of importance that form the result of the worse reservoir space. Modified by tectonics, the clastic rocks became the better reservoir of oil and gas with its high porosity and permeability in the Tula Basin.

Key words: Tula Basin, Jurassic, diagenesis, compaction, diagenetic stages

摘要： 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。

关键词: 侏罗系, 成岩作用, 压实, 成岩阶段, 吐拉盆地