北海维京地堑Beryl湾中、晚侏罗世高分辨率沉降分析及其意义

MIDDLE-LATE JURASSIC HIGH-RESOLUTION SUBSIDENCE ANALYSIS AND ITS IMPLICATION OF THE BERYL EMBAYMENT, VIKING GRABEN, NORTH SEA

在Beryl湾发育南北向、北西向和北东向三组正断层。根据北海维京地堑Beryl淘73口井的高分辨率层序地层学分析和高分辨率沉降分析，阐明中、晚侏罗世沉积和沉降模式，确定应力场的变化及边界断层的连锁对沉积和含油气系统的控制作用。高分辨率（1～2Ma）允许评价不同走向断层随时间的演化。不仅阐明了东舍德兰断层连锁的时间和机制，而且阐明了对沉积相的控制作用。研究结果表明，在中、晚侏罗世同裂谷期Beryl湾伸展方向发生了45°的顺时针旋转；东舍德兰断层在早、中牛津期由两段连锁为一条统一的断层。

Three sets of normal faults, with N-S, NW-SE and NE-SW orientations, have been recognized in the Beryl Embayment.Based on the high-resolution sequence stratigraphy and subsidence analyses of 73 wells in the Beryl Embayment, Viking Graben,North Sea, this paper tries to describe the sedimentation and subsidence models of the Middle-Late Jurassic syn-rift phase, andto determine the timing and location of boundary fault linkage and variation of active extension directions, and their control onsedimentation and petroleum system. High temporal resolution (1 to 2 million years per data point) has allowed an assessmentto be made of temporal evolution of faults with different orientations. The results indicate how and when the East Shetland Faultlinked and controlled sedimentary facies distributions and petroleum system in the Beryl Embayment. The results imply thatthere was a sequential variation in extension direction in the Middle-Late Jurassic, with 45°of an overall clockwise rotation invertical in the dominant orientation of active normal faults. The East Shetland Fau1t can be divided into a northern part and asouthern part which were linked together during the Early-Middle Oxfordian.