阿尔金山南缘吐拉盆地侏罗系砂岩储集性特征

RESERVOIR CHARACTERS OF THE JURASSIC SANDSTONES IN THE SOUTH MARGIN AREA OF THE ALTYN TAGH

在大量岩石薄片和铸体薄片研究的基础上，运用常规物性、毛细管压力曲线和图象分析等手段，对吐拉盆地侏罗系砂岩的孔渗性及孔隙结构等特征作了详细研究。孔隙类型主要为次生溶孔，偶见剩余原生粒间孔，它们基本上属于低孔低渗储集层，同时孔隙的微观结构较差。强烈的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；这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，在有利部位可以形成较好的储层。

With numerous observations on thin sections and casting sections of the rocks,and the application of various analytical techniques including conventional analysis of the core,capillary pressure curve and pore permeability distribution and pattern analysis of pore structure,the property of the pore and permeability and pore structure of the Jurassic reservoir sandstone in Tula Basin,southern Altyn Tagh,Xinjiang are carefully studied.The type of the pore are mainly secondary solution pores but primary remnant intergranular pores can be found ocasionally.Their reservoir character belongs basically to the reservoir with low prosity and permeability.Intense compaction is the major factors turning the worse pore texture of the sandstone.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 Tula Basin.