塔里木盆地构造活动枢纽部位碳酸盐岩油气聚集

为了更好地指导塔里木盆地碳酸盐岩的勘探实践 ,进一步认识叠合盆地油气富集规律 ,从塔里木盆地构造活动枢纽部位的形成、分布以及对油气聚集的控制入手 ,剖析了碳酸盐岩油气藏的宏观分布规律 .结果表明 ,构造活动枢纽部位寒武—奥陶系碳酸盐岩的圈闭类型主要为潜山及背斜 ;碳酸盐岩含油气层的储集层有不整合面以下的风化壳及碳酸盐岩内部的孔缝发育带 .相对凹陷而言 ,构造活动枢纽部位处在比较高的部位 ,正是油气运移的指向区 ;而相对于翘起的高部位来说 ,构造活动枢纽部位又处在相对较低的部位 ,极有利于油气藏的保存 .塔北隆起牙哈潜山油气藏、巴楚隆起和田河气藏以及塔中隆起西北倾没部位的塔中 45油藏都是很好的例证 .由此可见 ,塔里木盆地构造活动枢纽部位是碳酸盐岩聚集油气的有利地区 .目前所要解决的问题是采用各种方法识别出更多隐伏的构造活动枢纽部位 ,为发现更多的油气田提供靶区

Accumulation of petroleum in the carbonate rocks in the pivot positions of structural activities in Talimu Basin

The formation and the distribution of the pivot positions of structural activities in Talimu Basin, and their control effect on petroleum accumulation are analyzed. Based on the analyses, the distribution law of the carbonate reservoirs in this area is discussed. It is shown that, buried-hill and anticline are the main trap types of Cambrian to Ordovician carbonates, and the carbonate gas-bearing reservoirs are the weathering crust under unconformity surface and the pore-fracture developing zones in carbonate rock. The structural pivot positions are the pointing areas of petroleum migration because the positions are higher than the sags that are the source of oil and gas, and they are also the favorable positions of petroleum preservation because they are lower than the high parts of the warps that are violently eroded. The typical examples are Yaha buried-hill oil/gas field located on the northern slope of Tabei uplift, Hetianhe gas field located in the border of Bachu uplift and Tazhong45 oil field located in the northwestern pitching part of Tazhong uplift. Therefore the structural pivot positions are the favorable areas for petroleum accumulation in the carbonates in Talimu Basin. The key problem to be solved is to distinguish more structural pivot positions by using various methods and provide more targets for the exploration of oil/gas.