辽河外围陆家堡凹陷庙31块九佛堂组下段特殊岩性储层特征及成因机理

Characteristics and Genetic Mechanism of Special Lithology Reservoir of Lower Member of Jiufutang Formation in Miao 31 Block of Lujiabao Concave, Liaohe Peripheral Basins

摘要: 辽河外围盆地陆家堡凹陷九佛堂组为主力出油层段，九下段时期以沉积作用为主，火山喷发作用相对减弱，但仍然有一定量的火山岩喷发，沉积岩层中形成了火山岩夹层和凝灰质砂岩层等，岩石组成极为复杂，储层发育的受控因素认识不清。为此，本研究从基础的实验分析测试入手，深入开展岩性、储层、成因环境等相关研究。本文综合运用了岩石薄片鉴定、X-衍射全岩分析、铸体图像薄片分析、物性分析等分析测试技术，对辽河外围陆家堡凹陷庙31块九下段特殊岩性储层特征及成因机理进行研究，认为：庙31块九下段主要储集岩为硅化凝灰岩，是火山期后硅质热液改造形成的一类特殊储层；该类岩石储集空间类型以硅质热液、火山活动共同改造的残余孔、溶孔、裂缝为主；为以特低–低孔、特低–低渗为主，次为中孔、中渗，少量高渗储层。

Abstract: Lower member of Jiufutang formation is the main oil layer of Miao31 block in Lujiabao concave of Kailu of Liaohe peripheral basins. Sedimentation is the main activity with decreased volcanic eruption, formed volcanic rocks and tuffaceous sandstone. With extremely complicated rock composition, the control factors and mechanism of the reservoir development were hardly known. Therefore, starting with basic experimental analysis, we deeply develop lithological characteristics, reservoir characteristics, genetic environment and other researches. By a comprehensive ap-plication of rock thin-section identification, X-ray diffraction analysis, casting body slice image analysis, physical property analysis and other analyses and testing technology, the characteristics and genetic mechanism of special lithology reservoir of lower member of Jiufutang formation in miao31 block of Lujiabao concave of Liaohe peripheral basins were studied. We consider that sili-cified tuff is the main reservoir rock of lower member of Jiufutang formation in Miao31 block, the forming mechanism of this special lithology reservoir is the joint action of volcanic activities and siliceous hydrothermal. Its reservoir space is mainly residual inter-granular pore, dissolved pore and fracture. The special lithology reservoir is ultra-low and low porosity and permeability re-servoir, middle porosity and permeability reservoir takes second place. It has a few high permea-bility reservoirs.