基于反褶积短时傅里叶变换的薄储层流体识别——以元坝为例  

Identification of Fluid Based on Deconvolution Short-time Fourier Transform——Taking Yuanba Area as an Example

作　　者：盛秋红[1] 张金明[2] 

机构地区：[1]中国石油化工股份有限公司勘探分公司勘探研究院,成都610041 [2]成都理工大学地球物理学院,成都610059

出　　处：《科学技术与工程》2016年第15期41-46,共6页Science Technology and Engineering

基　　金：国家科技重大专项(2011ZX05005-005);国家自然基金(41174114);"油气藏地质及开发工程"国家重点实验室开放基金(PLC201402)资助

摘　　要：元坝地区长兴组台地边缘礁滩相储层油气资源潜力巨大,礁后滩储层厚度薄,气水识别是该区的勘探难点之一。低频伴影是进行流体识别的有效方法,但对薄储层进行流体识别难度巨大。为此,引入了反褶积短时傅立叶变换。相较于传统时频分析方法有更高的时间分辨率和频率分辨率。由于该方法利用了信号短时傅里叶变换,在理论模型和实际数据分析中发现同一地震剖面取不同时窗时其"低频阴影"油气检测结果存在很大差异。为此,通过建立模型以及实际地震数据实验,得到了最佳时间和频率分辨率的地震主频与时窗组合关系式。在此基础上可进行高分辨的低频伴影分析。实例应用表明该方法效果明显。The reserves of Yuba Back Reef Strands Reservoir in Changxin group is large but the thickness of reservoir is thin,therefore,identification of gas and water is one of the most difficult problems. Although the analysis of low frequency shadow is a good way to identify liquid,it hardly identify liquid in thin reservoir. To solve this problem,Deconvolution Short-time Fourier transform was introduced. Compared with traditional problem,it provides higher time-frequency resolution. Because STFT is applied in this method,the window adopted in the transform will affect identification result heavily. Relationship between seismic dominant frequency and time window were set to obtain best time-frequency resolution by establishing model and analyzing seismic data. Based on the above,low frequency shadow analysis can be made with high resolution. Practical application shows it can improve the result.

关 键 词：WIGNER-VILLE分布 短时傅里叶变换 反褶积 时窗长度 地震主频 

分 类 号：P631.443[天文地球—地质矿产勘探]