准噶尔盆地二叠系不整合面及其油气运聚特征

The unconformity surface in the Permian of Junggar basin and the characters of oil-gas migration and accumulation

准噶尔盆地二叠系存在的多个不整合面对于油气的长距离大规模运移及油气的富集具有极为重要的作用。地震剖面综合解释显示,二叠系不整合面共分4种类型:断褶不整合、削截不整合、超覆不整合、平行不整合,油气沿不整合面运移规律受不整合类型控制。在测井曲线组合对比分析的基础上,结合岩心观察,将不整合面上、下分为三段式结构:底砾岩、风化黏土层、风化淋滤带。这种结构构成油气运移的双重通道,它把不同时代的储集层、断裂等连接起来,组成区域性的运移通道网络。准噶尔盆地二叠系不整合面不仅是油气运移的重要通道,而且是油气聚集的良好场所,在不整合面之下形成不整合遮挡油气藏,在不整合面之上形成地层超覆岩性油气藏。图8参13（吴孔友摘）

There are many unconformity surfaces in Permian system of Junggar basin, which are very important for oil and gas to migrate with long-distance and in great-scale and to accumulate. Seismic section comprehensively interpreted to discover that patterns of unconformity sections in the Permian include fold unconformity, fault-fold unconformity, truncation unconformity, onlap unconformity and parallel unconformity. Each of them has the different distributing regularities in basin, and the type of unconformity surface controls oil and gas migration along it. On the basis of analyzing log responses and cores, the unconformity surfaces in vertices are divided into three parts: under-conglomerate, weathering claystone and paleokarst zone, this structure forms the double paths of the oil and gas migration. It connects reservoirs and faults which formed in different times to construct the regional migrating network. The unconformity surfaces in the Permian of Junggar basin not only are the important paths for the oil and gas migration, but also are the good places for the oil and gas accumulation. Undersurfaces can form reservoirs which are covered by the unconformity surfaces, and upsides can form lithologic reservoirs characterized by stratum onlapping.