鄂尔多斯盆地麻黄山西区块长6油组致密储层特征及物性主控因素研究

根据鄂尔多斯盆地麻黄山西区块大量的岩心、测井、录井和分析化验资料,从储层岩石学特征、物性特征、孔隙类型及孔隙结构三个方面对长6油组储层特征进行研究。针对储层超低-特低孔、超低-特低渗的特点,从沉积相和成岩作用两方面对致密储层物性的主控因素进行分析。研究表明,长6油组储层岩石类型主要为岩屑质长石砂岩和长石质石英砂岩,成分成熟度和结构成熟度中等-好;储集空间主要为原生粒间孔隙和粒间溶孔,孔隙结构以微喉道和片状喉道为主。水下分流河道砂体物性最好,为最有效储层;压实和胶结作用均导致储层物性变差,溶解和交代作用有利次生孔隙形成;但程度较弱,对储层改造作用有限。

Research of the tight reservoir characteristics and main physical property influencing factors of Chang 6 formation reservoir in west area of Mahuangshan, Ordos Basin

Based on lots of cores, logging and analysis test data of the west Mahuangshan in Ordos Basin,we studied the reservoir characteristics of formation Chang 6 from the lithological characteristics, physical characteristics, pore types and pore structure three aspects. As the reservoir is extra-ultra low porosity and permeability, we analysis the sedmentary microfacies and the diagenesis to study the main physical property influencing factors of the tight reservoir. The study has shown that the rock types of formation Chang 6 are lithic-feldspar sandstones and feldspar quartz sandstone, the textural and compositional maturation of the reservoir is mediocre-good. The major reservoir space are primary intergranular pore and intergranular dissolved pore,the micro throat and the lamellar throat is the main pore structure. The underwater distributary channel sands is the best effective reservoir with the best physical characteristics. Compactin and cementation is the main reason of the bad reservoir physical characteristics while corrosion and metasomatism played very important roles in the development of secdary pores, but weaker effect, and the reformation of the reservoir is limitited.