中文摘要：

鄂尔多斯盆地陇东地区延长组是该地区的主要产油层，素以“低孔低渗”而闻名。根据岩心观察、薄片鉴定、粒度分析和扫描电镜、阴极发光和X衍射等分析化验对该地区延长组储层的岩石学特征及其变化规律进行了深入研究。研究表明，陇东地区延长组砂岩储层岩石类型主要为细-中粒岩屑质长石砂岩和长石质岩屑砂岩；成分成熟度较低；总体上从西部耿湾环县向东至合水塔儿湾，砂岩成分成熟度逐渐增高；下部的长8长10及上部长1长4＋5较粗，为中-细粒砂岩，中部长6、长7较细，多为粉细砂岩。砂岩岩屑含量高、类型丰富，发育泥岩、白云岩等沉积岩岩屑，喷发岩、花岗岩等岩浆岩岩屑及板岩、千枚岩、片岩等变质岩岩屑，其中长8-长10以喷发岩岩屑为主，含量东西差异小，长1长7以白云岩岩屑为主，含量西高东低；变质岩岩屑各层段都存在；云母在东部含量较高。按岩屑对成岩作用的影响分为刚性和塑性两大类，其中刚性可再细分为易溶与难溶两类，塑性可细分为易压实变形及易蚀变两类。此项研究成果对于分析延长期的盆地演化、物源类型及储层后期成岩作用及孔隙演化具有重要意义。

英文摘要：

The Yanchang Formation of Triassic System of Longdong Area in Ordos Basin is the main productive bed of this area, which is characterized by low porosity and low permeability. Rock properties and the law of its distribution are studied in this paper, based on core description, thin section study and quantitative statistics. Technical analysis and measurement such as X diffraction analysis, scanning election microscope observation, catbodoluminescence are also used. The research shows that the main rock types of Yanchang Formation are lithic feldspathic sandstones and feldspathic litharenite sandstones with low compositional maturity. The maturity increases gradually from west to east. The grain sizes of the lower members such as Chang8 Chang10 and the upper members, Chang1 - Chang4--5 are coarse, and the lithology of these members is mainly composed of medium fine grained sandstones; while the particle sizes of Chang6 - Chang7 in the middle members are relatively fine, and the lithology is mainly composed of sihstones. The debris content is high and the types of debris are various. They include mudstone, dolomite and other sedimentary rock debris; the volcanic rock, granite and other magmatic rock debris; and slate, phyllite, schist and some other metamorphic rock debris. The debris type of Chang8 - Chang10 oil beds is mainly volcanic rock. The type of Changl- Chang7 is dolomite debris and the content is high in the west than that in the east. Metamorphic detritus exists for all the oil beds of Yanchang Formation, and the content of mica is higher in the east. By considering the roles of detritus and mica and the role of them playing in diagenesis, the detritus can be divided into two categories, the rigidity and plasticity, and the rigid debris can be further divided into soluble and insoluble, while the plastic debris can also be divided into two types, one is easy to be altered, the other is easy to be deformed. The above research is important for the subsequent researches such as the evolution of Ordos Basin,