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摘要：喀拉扎背斜位于准噶尔盆地南缘，发育侏罗系油砂。在喀拉扎背斜侏罗系头屯河组首次发现6个油砂露头点，并实施地质调查井1口（喀油砂1井），揭示油砂储层累计厚度超过30 m。通过钻井岩芯编录、岩石薄片鉴定、扫描电镜观察、铸体薄片观察和测井等方法，对油砂储层的沉积环境、岩性、物性和储集空间类型等进行了研究。结果表明：油砂储层位于中侏罗统头屯河组，主要包括中细砂岩油砂储层和粗砂—细砾岩油砂储层；中细砂岩油砂储层为厚层沉积岩储层，沉积相属于曲流河相河床亚相的边滩沉积微相，储集空间以原生孔隙为主，孔隙度和渗透率为中—高孔、高渗范畴；粗砂—细砾岩油砂储层为特厚层沉积岩储层，沉积相属于曲流河相河床亚相的河床滞留沉积微相，储集空间以次生孔隙为主，孔隙度和渗透率为中孔、中渗范畴。总之，喀拉扎背斜侏罗系头屯河组储层有利于油砂的富集与储存，是准噶尔盆地油砂资源新的潜力区。
关键词：油气地质；油砂；储层特征；沉积相；孔隙度；含油率；喀拉扎背斜；准噶尔盆地
中图分类号：P618.130.1；TE122.2+4文献标志码：A
Abstract： Kalazha anticline is located in the southern margin of Junggar Basin， and oil sand develops in Jurassic. 6 outcrops of oil sands in Kalazha anticline have been found in Jurassic Toutunhe Formation for the first time. One well has been drilled in the oil sandbearing layer， and the thickness of oil sand layers found is more than 30 m. Based on the core recording， identification of rock sections， SEM， identification of casting sections and core logging， the sedimentary environment， lithology， physical property and space types of oil sand reservoirs were studied. The results show that the oil sand reservoirs belong to Middle Jurassic Toutunhe Formation， including middlefine sandstone and coarse sandfine conglomerate oil sand reservoirs； the middlefine sandstone oil sand reservoir is thick sedimentary rock， and the sedimentary facies is marginal microfacies of riverbed subfacies， meandering river facies， and the reservoir space is mainly primary pore， and the porosity and permeability are middlehigh and high， respectively； the coarse sandfine conglomerate oil sand reservoir is extra thick sedimentary rock， and the sedimentary facies is riverbed retention microfacies of riverbed subfacies， meandering river facies， and the reservoir space is mainly secondary pore， and both of porosity and permeability are middle. In general， the reservoirs in Jurassic Toutunhe Formation in Kalazha anticline are favorable for the eichment and storage of oil sands， and will be one of the potential areas of oil sand resource in Junggar Basin.
Key words： petroleum geology； oil sand； reservoir characteristic； sedimentary facies； porosity； oil content； Kalazha anticline； Junggar Basin
0引言
油砂是非常規资源的一种。广义的油砂定义为出露地表或近地表（常规油气资源深度以浅范围）的砂岩和碳酸盐岩中的烃类，烃类可以是重油、轻油或者固体沥青等[12]，本文研究的就是广义的油砂。准噶尔盆地是中国重要的常规油气和非常规油砂资源富集区之一。陈建平等研究认为：准噶尔盆地南缘构造十分复杂，背斜圈闭众多，具有东西分段、南北分带的构造特点；不同区段成藏期次不同，油气勘探过程中在很多圈闭中均发现了油气显示，如齐古背斜、霍尔果斯背斜等[34]。对于喀拉扎背斜，吴晓智等研究发现在该区侏罗系三工河组地层有油气显示[5]。此外，该区侏罗系头屯河组地层属于辫状河曲流河转换沉积体系，其中含砾砂岩储层储集性能良好，而砂岩储层储集性能较差[6]。以上研究成果为准噶尔盆地油砂储层的研究工作提供了基础，但是针对喀拉扎背斜侏罗系头屯河组油砂储层，目前缺乏对其沉积相、储集空间、物性特征等的系统研究与评价。