CAJ | 학술논문

为明确鄂尔多斯盆地镇北地区延长组长8段低渗透储层成因，综合运用铸体薄片、阴极发光照片、扫描电镜照片等分析化验资料进行研究，发现其储层岩性以浅灰色、灰色岩屑质长石砂岩和长石质岩屑砂岩为主，表现为成分成熟度低、碎屑岩成分复杂，储层物性总体较差；发育粒间孔、溶蚀孔，孔隙结构主要为小孔隙、微细喉道型，孔隙度为7%~13%，渗透率为0.1×10-3μm2-3×10-3μm2，属于低渗透储层；研究表明制约研究区低渗透主要存在内因和外因两个方面，其中内因包括粒度、易压实岩屑和云母含量，而压实及溶蚀等成岩作用是其外因；胶结作用和软颗粒变形填充作用是造成储层进一步低渗的关键因素.
위명학악이다사분지진북지구연장조장8단저삼투저층성인，종합운용주체박편、음겁발광조편、소묘전경조편등분석화험자료진행연구，발현기저층암성이천회색、회색암설질장석사암화장석질암설사암위주，표현위성분성숙도저、쇄설암성분복잡，저층물성총체교차；발육립간공、용식공，공극결구주요위소공극、미세후도형，공극도위7%~13%，삼투솔위0.1×10-3μm2-3×10-3μm2，속우저삼투저층；연구표명제약연구구저삼투주요존재내인화외인량개방면，기중내인포괄립도、역압실암설화운모함량，이압실급용식등성암작용시기외인；효결작용화연과립변형전충작용시조성저층진일보저삼적관건인소.
To study the cause of low permeability reservoir of chang-8 member of Yanchang formation in Zhenbei area of Erdos Basin,we synthetically use the testing data such as casting thin sections,the pictures of cathodoluminescence and SEM. The lithology of reservoir were mainly light gray,gray lithic arkose and feldspathic lithic sandstone. The compositional maturity of reservoir rock is low and the composition of reservoir rock is complicated. The reservoir physical properties are worse. The reservoir mainly develops intergranular pores and dissolved pore ,and pore structure types are fine pore and microscopic throats,with the porosity ranging from 7% to 13%,as well as the permeability being 0.1 × 10-3μm2 to 3 × 10-3μm2. In a word,it is low permeability reservoirs. The results show that the causes of low permeability reservoirs in studied region are from two respects of the internal and external causes. The internal causes include particle size,and the contents of easy compaction cuttings and mica. The external causes include diagenesis,and compaction. Cementation,deformation and filling of soft sphere are the key factors that cause low permeability reservoirs more worse.