顺北1号断裂带洞穴型储集体地震表征方法

顺北油气田1号断裂带奥陶系储层为碳酸盐岩断控缝洞型储集体，储集体在三维空间内差异较大，非均质性极强。1号断裂带以串珠地震反射特征为主，实钻证实储集体以洞穴为主，常规的波阻抗反演方法在刻画洞顶具有很好的效果，但是在刻画洞底和洞的宽度误差较大，不能精准刻画出洞穴的外轮廓，钻井轨迹设计靶点会出现偏差，钻井过程中不发生放空与漏失，需要酸压完井，增加完井成本的同时还有可能打出失利井，因此对该类储集体的有效识别和精细表征是油田增储上产的关键。基于正演模拟，针对串珠反射储集体开展了地震表征方法探索与地震属性敏感分析；对于串珠反射特征的洞穴型储集体，利用微分振幅与瞬时能量融合属性能够较好地刻画顺北1号断裂带洞穴的顶底及宽度。实际资料的预测结果与实钻井特征吻合程度高，预测与实钻吻合率达89%,验证了顺北1号断裂带洞穴型储集体表征方法的可靠性。

Seismic Characterization Method of Cave Type Reservoir in Shunbei No.1 Fault Zone

The ordovician reservoir in Fault Zone 1 of Shunbei oil and gas field is a fracture-vuggy carbonate reservoir, which is different in 3D and highly heterogeneous. In Fault Zone 1, beaded seismic reflection is the main feature, and it is confirmed by drilling that the reservoir is mainly cave. The conventional wave impedance inversion method has a good effect in depicting the cave roof, but the error in characterizing the cave bottom and the width of the cave is large, it can not accurately depict the outline of the cave, the design target of the drilling trajectory will be deviated, there will be no venting and leakage in the drilling process, and acid fracturing completion is needed, which will increase the completion cost and possibly drill a failure well at the same time, therefore, the effective identification and fine characterization of this kind of reservoir is the key to increase oil production. Based on forward modeling, seismic characterization method and seismic attribute sensitivity analysis were carried out for beaded reflection reservoir, the top, bottom and width of the cave in Shunbei No. 1 fault zone could be well characterized by using the fusion property of differential amplitude and instantaneous energy. The predicted results are in good agreement with the actual drilling characteristics, and the coincidence rate is 89% , which verifies the reliability of the method for characterizing cave reservoirs in Shunbei No. 1 fault zone.