浅层岩性气藏地震检测的陷阱分析

利用AVO地震检测技术检测的地震亮点在济阳坳陷直接寻找浅层岩性气藏取得了丰富的地质成果。但是 ,在地震检测技术的应用中也存在着陷阱 ,致使一部分探井落空。为了在今后实际勘探中避开这些陷阱 ,从地质和地震两方面探讨了形成陷阱的原因。研究结果表明 ,地下火成岩等特殊地质体和岩石的非均质性可形成比较强的地震反射 ,使天然气藏的地震检测存在陷阱 ;另外 ,受水平分辨率的限制 ,二维地震剖面圈出的亮点不能准确地反映天然气藏圈闭的实际范围。

Pitfall analysis of seismic detection in shallow layers of lithologic gas reservoir

The plentiful geologic results were acquired in directly prospecting shallow layers of lithologic gas reservoir using seismic bright spot and AVO information techniques in Jiyang depression. However, there are many pitfalls in application of the seismic detection technique, which makes a part of exploration wells failed. In order to avoid these pitfalls in real exploration, the causes for forming pitfalls in geologic and seismic aspects were investigated. The main causes are the lateral resolution of seismic data and the strong reflection resulted from some special geologic bodies such as subsurface igneous rock, heterogeneous formation. In addition, the bright spots on 2-D seismic sections cannot correctly reflect the real range of gas reservoirs because of the horizontal definition limits.