冀中坳陷新河凸起变质岩油气藏成藏条件探讨

Discussion on hydrocarbon accumulation conditions of the metamorphic rock reservoir in the Xinhe uplift of the Jizhong depression

地震和钻井资料表明,新河凸起变质岩潜山内幕具备成藏条件,毗邻束鹿和深县两大生油凹陷,古近纪沙三段生油岩生成的油气分别通过新河断裂、衡水断裂输送到新河凸起变质岩潜山中;经历多次构造运动,具备裂缝大规模发育的条件。由于岩性以及受力的不均一,导致裂缝发育分布不均一,深色变质岩致密,裂缝、节理极不发育,具有良好的封盖条件;浅色变质岩裂缝发育,可作为储层,这种"深盖浅储"储盖组合模式是新河凸起变质岩潜山内幕储盖组合的主要形式之一。

Seismic and drilling data have shown that the internal metamorphic rock buried hill in the Xinhe uplift possesses the conditions of hydrocarbon accumulation.The oil and gas generated from the adjacent Paleogene Es3 source rocks in the Shulu and the Shenxian generation sags were transported to the metamorphic rock buried hill in the Xinhe uplift via the Xinhe fault and the Hengshui fault.This structure had undergone many tectonic movements,having the conditions of developing large scale fractures.The development of fractures was uneven due to lithology and stress.The dark metamorphic rock is tight,has undeveloped fracture and joint,showing good sealing condition;the light metamorphic rock had developed fractures and could be reservoirs.This 'dark-seal light-reservoir' pattern constitutes one of the major patterns of reservoir-seal assemblage of the internal metamorphic rock buried hill in the Xinhe uplift.