【摘要】 地震解释和沿层相干切片,结合储层沉积特征对松辽盆地三肇凹陷南部肇州油田层控多边形断层的发育特征进行研究。研究结果表明:该区层控断层定向排列,展布方位与斜坡走向平行,并向着斜坡上倾方向倾斜,其发育时期与青山口组末期—姚家组沉积早期的构造抬升事件相对应,地层翘倾引起的重力滑动作用被认为是驱使断层活动的成因。层控多边形断层的平面展布受砂体和构造断层的影响,集中分布在含砂地层厚度较薄的区域,并且多向着构造断裂下盘生长。在不同地质历史时期,多边形断裂的启闭性质不同,其在油成藏中的作用也不同。成藏期(明水组末期)区域应力场为北西向挤压,北西—北北西向沟通青一段源岩和葡萄花油层的活动断裂是垂向输导油的油源断裂,而此时东西展布的层控断裂受正向挤压,断面紧闭,对油成藏主要起遮挡作用。新生代以来至现今区域应力场转变为近东西向挤压,层控多边形断层展布方位与现今最大水平主应力方向一致,具有高渗透性,成为油在低渗透储层内侧向运移的高渗透通道,促进油藏连片分布。更多还原

【Abstract】 Through the 3D seismic data interpretation and coherence slices, combined with depositional characteristics of Putaohua reservoir, the development characteristic of layer-bound polygonal faults(PFs) was studied in Zhaozhou oilfield in the south of Sanzhao depression, Songliao Basin. The results show that the layer-bound faults show preferential alignment, that most faults distribution are parallel to the strike of the slope and that aligned faults incline to updip direction of slope. The development period of PFs is coincided with a late Qingshankou stage to early Yaojia stage tilting event, and gravity sliding model is proposed as a possible mechanism for the deformation. Plannar distribution of the faults is controlled by sand body and tectonic faults, PFs mainly concentrate in the area where sandstone-bearing stratum is thin, and individual PFs mostly grow to the footwall of the tectonic faults. Because of the difference in the activity of PFs in geological times, there are differences in the role of faults in hydrocarbon accumulation. The regional stress field of hydrocarbon accumulation period(the end of Mingshui formation) is NW trending compressive stress, NW—NNW faults where oblique slipping occur are pathways for oil migrating vertically from the source rock of the Qing-l member up to Putaohua reservoir, yet layer-bounding EW trending faults are closed under normal compression, so PFs play seal effect in hydrocarbon accumulation. Since the Cenozoic, regional stress field transforms into EW trending compression, PFs oriented parallel or nearly parallel to the maximum horizontal principal stress show high permeability. PFs are expected to be the dominant lateral migration pathways for oil within low-permeability reservoir, and make oil reservoir interconnected.更多还原