Abstract: The subtle reservoir of carbonate rock in Lunguxi buried hill is a dissolution fissure-cave reservoir distributed along the top of Ordovician unconformity where oil-gas distribution is uncontrolled by local structural high.The main pathway of fluid migration in the buried hill is a complex 3D network system formed by dissolution fissure-hole-cave staggered,incised and connected mutually and distributed mainly in the section within 160 meters of depth below the top of buried hill.Oil-gas migration occurred along the path with the least resistance in dissolution fissure-cave system under the drive of buoyancy.Three factors dominate the process of oil-gas migration and accumulation.First,development of fissure-hole-cave controls the forming of subtle trap and the spatial distribution of fluid transport channels.Second,structural pattern controls the regional final direction and local tropism of oil-gas migration.The last,the space configuration among structural pattern,fluid transportation channel and oil source dominates the spatial distribution of oil-gas migration pathway.So the favorable belt for oil and gas accumulation of Lunguxi buried hill can be predicted and evaluated by synthetic analysis based on multiple factors.

Key words: Tarim Basin, buried hill, subtle reservoir, carbonate rock, unconformity structure, oil-gas migration

摘要： 轮古西潜山油藏是沿奥陶系顶部不整合构造分布的碳酸盐岩古岩溶缝洞型隐蔽油藏,油气分布不受现今局部构造高点控制.潜山流体运移的主要通道是由岩溶缝、孔、洞相互交错、切割、连通所构成的复杂三维网络体系,主要分布于距潜山顶面0~160m深度段.在岩溶缝洞体系内,油气受浮力驱动并取道阻力最小的路径发生运移.其运聚过程主要受以下3个因素的控制:①缝、孔、洞发育带控制了圈闭的形成和流体输导通道的空间分布;②构造格局控制了油气运移的区域最终指向和局部运移取向;③构造格局、流体输导体系和油气供给源三者之间的空间配置决定了油气运移路径的空间分布.由此,可应用多参数综合分析方法对本区油气富集的有利区带作出预测和评价.

关键词: 塔里木盆地, 潜山, 隐蔽油藏, 碳酸盐岩, 不整合构造, 油气运移