塔里木盆地塔中北坡奥陶系碳酸盐岩岩溶储层的形成机理

发布时间：2018-10-04 21:31

【摘要】：塔里木盆地塔中北坡奥陶系碳酸盐岩储层已成为该盆地油气勘探的重要目标之一,目前对于该岩溶储层的溶蚀机制尚存在争议。为此,基于沉积、层序与储层综合研究成果,结合微观分析测试与宏观地震资料分析结果,将该区碳酸盐岩岩溶储层划分为石灰岩溶蚀孔洞型、白云岩孔洞型和硅质岩裂缝孔洞型3种类型,并分别探讨了其形成机理。结果表明:(1)石灰岩溶蚀孔洞型储层纵向上分布在中奥陶通鹰山组上段和一间房组,而白云岩孔洞型储层主要发育在下奥陶统蓬莱坝组和鹰山组下段且厚度较大;(2)石灰岩溶蚀孔洞型储层形成于三级层序界面(低位期)岩溶作用,而白云岩孔洞型储层则主要形成于受三级层序界面岩溶作用控制的深埋藏白云石化作用,两者均分布在三级层序界面之下的高位体系域;(3)该区硅质岩储层的发育明显受断裂控制,是深部热液沿断层对石灰岩改造的结果,硅质岩储层及其热液溶蚀缝洞系统分布在断裂附近。进而推测:塔中北坡奥陶系除了发育上述3种储层类型以外,还发育台地边缘礁滩型储层。
[Abstract]:Ordovician carbonate reservoir on the northern slope of Tarim Basin has become one of the important targets of oil and gas exploration in this basin. Therefore, based on the comprehensive research results of sedimentation, sequence and reservoir, combined with the results of microscopic analysis and seismic data analysis, the carbonate karst reservoirs in this area are divided into limestone dissolution voids. The formation mechanism of dolomite pore type and siliceous rock fracture hole type is discussed. The results show that: (1) the limestone cavities are distributed vertically in the upper member of the Yingshan formation and the Yijianfang formation in the middle Ordovician formation. The dolomite porosity reservoir is mainly developed in the lower member of Penglai Ba formation and Yingshan formation of Lower Ordovician, and the thickness of the reservoir is large. (2) the limestone dissolution porosity reservoir is formed in the third order sequence interface (low stage) karstification. The dolomite porosity reservoir is mainly formed by the deep-buried dolomitization controlled by the third-order sequence interface karstification. (3) the development of siliceous reservoir in this area is obviously controlled by fault, which is the result of the reconstruction of limestone by deep hydrothermal solution along the fault. The siliceous reservoir and its hydrothermal solution system are located near the fault. In addition to the above three reservoir types, the Ordovician on the northern slope of Tazhong also developed reef and beach reservoirs on the terrace margin.
【作者单位】：成都理工大学能源学院;成都理工大学沉积地质研究院;
【基金】：中国石化西北油田分公司科研项目“塔中北坡奥陶系储层成因及发育模式研究”(编号:34400000-14-ZC0607-0031)
【分类号】：P618.13

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