顺北油气田奥陶系断控体结构模式研究

顺北油气田奥陶系目的层埋深普遍在8 000 m左右，三维地震资料采集面元25 m×25 m,地震资料分辨率较低，导致顺北油气田奥陶系鹰山组断控体油气藏难以精细刻画与表征。结合常规测井、电成像、远探测、取芯等资料，开展不同应力作用下断控体结构分析、断控体油气藏破碎裂缝带、破碎角砾带、断裂空腔分布研究。结果表明：断控体油气藏主要储集空间来自多期构造活动叠加改造形成的断裂空腔、角砾间孔隙、构造裂缝，不同应力机制决定断控体的发育程度，拉张背景易形成断裂空腔及裂缝带，挤压背景易形成破碎角砾带及裂缝带；断控体常发育典型的核带结构，裂缝带的宽度范围较大(0.35～1.64 km),且分布范围广，角砾带的宽度范围次之(0.44～0.93 km),且分布范围中等，断裂空腔的宽度范围最小(0.25～0.35 km),且分布范围小，主要集中在局部拉张应力区。

Study on Structural Model of Ordovician Fault-controlled Volume in Shunbei Oil and Gas Field

The depth of target layer of ordovician in Shunbei oil and gas field is about 8 000 m, 3d seismic data acquisition panel is 25 m ×25 m, the resolution of seismic data is low, it is difficult to describe and characterize the ordovician Yingshan fault-controlled reservoir in Shunbei oil and gas field. Based on the data of conventional logging, electrical imaging, remote detection and coring, the structure analysis of fault-controlled body, the fracture zone, fracture breccia zone and the distribution of fracture cavity in fault-controlled body reservoir under different stress were carried out. The study shows that the main reservoir space of fault-controlled body oil and gas reservoir comes from fault cavity, breccia pore and structural fracture formed by multi-stage structural activity, and different stress mechanism determines the development degree of fault-controlled body, the fracture cavity and fracture zone are easily formed in the tension background, and the broken breccia zone and fracture zone are easily formed in the compression background. The typical nuclear zone structure is often developed in the fault-controlling body, and the fracture zone has a wide width (0.35-1.64 km) and a wide distribution, the width of breccia belt is the next (0.44-0.93 km) , and the range of distribution is moderate. The width of fracture cavity is the smallest (0.25-0.35 km) , and the range of distribution is small, mainly concentrated in the area of local tensile stress.