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新太古代结晶岩基底潜山是渤海湾盆地重要的油气勘探领域,裂缝的发育与分布是该类潜山油气成藏研究的重点与难点,通常潜山裂缝储层发育于断裂带。通过对秦皇岛地区鸽子窝与北戴河新太古代结晶岩露头断裂带与区域性构造节理带裂缝观测与描述,建立了裂缝发育的露头模型。研究表明,断裂带由核部碎裂带与两侧节理密集带组成,单侧节理密集带的宽度大于40m,整个断层带的宽度大于100m。节理密集带的线密度可达到28条/m,而且裂缝尺度长,多个方向的裂缝构成连通的网络系统,是该类裂缝储层发育的最有利部位。节理密集带以外的区域性节理发育带,因裂缝发育密度低、尺度小、彼此不连通,不能形成有效裂缝储层。潜山裂缝储层的分布受断层的控制呈现高度的非均质性,裂缝发育带与致密带在空间上构成不规则块状分布。
The basement buried hill of Neo-Archean crystalline rock is an important oil and gas exploration area in the Bohai Bay basin. The development and distribution of fractures are the key and difficult points in the study of hydrocarbon accumulation in this type of buried hill. Usually, fractured reservoirs in buried hills develop in fault zones. Through the observation and description of the neo-Archean crystalline-rock outcrops and the fractures of the regional structural joints in Pigeonwo and Beidaihe areas in Qinhuangdao, the outcrop model of fracture development was established. The results show that the fault zone is composed of the nuclear fractured zone and the joint dense zones on both sides. The width of the unilateral dense zone is greater than 40m and the width of the fault zone is greater than 100m. The dense linear density of joints can reach 28 / m, and the fractures are long and the fractures in many directions form a network system, which is the most favorable site for the development of fractured reservoirs. Because of the low developmental density and small scale of fractures, the zone of regional joint development outside the dense belts can not form effective fractured reservoirs. The distribution of buried hill fractured reservoirs is highly heterogeneous due to the fault control. The fractured development zones and dense belts are spatially irregularly distributed.