东海陆架盆地丽水凹陷岩性油气藏发育特征与成藏条件

Development characteristics and accumulation conditions of lithologic reservoirs in Lishui sag, East China Sea shelf basin

独特的盆地构造特征和沉积旋回特征使得丽水凹陷具备岩性油气藏形成的基本沉积地质条件。目前丽水凹陷已发现证实的岩性油气藏有沟-坡-扇体系与扇三角洲体系两大类,油气主要来源于古新统月桂峰组和灵峰组主力烃源岩,岩性圈闭主要发育于古新统明月峰组和灵峰组的扇体中且处于"泥包砂"环境,作为沟通扇体与烃源岩的油源断层主要为边界大断裂,油气运移通道为成藏的主控因素。

Abstract.. In Lishui sag, the unique basin structure and sedimentary cycle have resulted in the basic sedimentary and geological conditions required to form lithologic reservoirs. Two major categories of lithologic reservoirs have been found in the sag so far, i.e. the vally-slope-fan system and the fan delta system. The hydrocarbon in these reservoirs was mainly {rom the maior source rocks in Yueguifeng and Lingfeng formation, and the lithologic traps largely developed in the fans of Mingyue{eng and Lingfeng formation and were in an environment of ＂sand wrapped by clay＂. The major boundary faults have served as the main hydrocarbon source faults to connect the fans to the source rocks, and the hydro- carbon migration pathways are one of the main controls of hydrocarbon accumulation.