高精度三维地震在泌阳凹陷北部复杂断块群勘探中的应用

The application of high precision 3-D seismic in complex fault blocks exploration of Biyang Depression.

泌阳凹陷北部斜坡带构造破碎,圈闭面积小,油藏埋深70～1200 m.为了得到断层和地质层位信息齐全的地震资料,从采集、处理和解释等方面进行了探讨。设计了基于模型的三维地震观测系统.采用新工艺解决了古河道和河床区激发接收条件差的问题,采用小道距、小线距、小偏移距和小炮线距技术解决了大规模障碍区浅层信息不全的问题;采用精细速度分析和叠前时间偏移等技术.提高了成像精度.剖面上断层清楚、信息丰富;采用三维可视化、面块切片和相干体分析等技术,搞清了断裂系统和断层的空间展布;采用综合评价技术,评价了有利含油气圈闭。通过以上技术的应用,目的层主频由原来的35 Hz提高到70～80 Hz.分辨出10 m左右的断层和单砂层.发现和落实了面积大于0.05 km2的小断鼻、断块和地层不整合圈闭.部署了15口预探井.有13口井钻遇油层。

The northern slope of Biyang Depression has shatter structure, small traps and oil layers depth with 70 -1200m. Application on integrative acquisition, processing, interpretation method, using layout design technique based on model and prestack time migration and 3-D visualization and surface-block slice and coherence cube analysis, establish to match technique on oil & gas prospecting of complex fault block. The seismic reflect under the 50ms has been entirely received. Dominant frequency has been improved from 35Hz to 70-80Hz, fault and single sand layers about 10m have been distinguished, bigger 0. 05km2 traps of small fault nose and block and unconformity have been found. There is 13 successful oil well in the 15 exploring well, probable reserves with 1078×104t has been found.