摘要
地下存在煤系地层时地震剖面上会出现强能量反射同相轴,使煤层之上或之下的含气目的层反射信息淹没于强反射之中,加大了储层预测难度。依据稀疏表示理论,提出匹配追踪煤层强反射分离方法。匹配追踪去煤层强反射的关键是稀疏字典的选取,通过地震数据在不同的一维字典中的稀疏性分析,并考虑强反射信息的低频特征,选取由低频原子构成的一维非抽样离散小波变换(UDWT1D)字典来稀疏表示强反射信息。采用Blumensath等给出的迭代算法进行匹配追踪分解,该算法虽是一种贪婪算法,但由于对每个地震道只需进行一次匹配分解,计算效率较高。模型数据测试和实际资料处理结果证明了该方法的有效性。
Strong reflection events occur in seismic section if coal seams exist in the study area.In this case,the reflection information from targets above or below the coal seam will be submerged in the strong reflection events.And then the reservoir prediction can hardly be carried out.Based on sparse representation theory,a method for separation of strong coal seam reflection via matching pursuit is put forward in order to deal with this problem.The key to remove coal seam reflection by matching pursuit is the choice of sparse dictionary.Through the analysis of seismic data sparsity in different one-dimensional dictionaries,and taking into account of low-frequency characteristics of strong reflection,the one-dimensional undecimated discrete wavelet transform(UDWT1D)dictionary composed of low-frequency atoms is adopted to sparsely represent the strong reflection information.The matching pursuit decomposition is carried out with the iterative algorithm proposed by Blumensath et al.,although this algorithm is a greedy algorithm,the decomposition is carried out only one time for each seismic trace,so the computational efficiency is high.Test results of theoretical model and real data verified the validity of the proposed method.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
2014年第5期866-870,818,共5页
Oil Geophysical Prospecting
基金
国家重大科技专项课题"大型油气田与煤层气开发"(2011ZX05007-006)资助
关键词
匹配追踪
煤层强反射
稀疏表示
过完备字典
储层预测
流体检测
matching pursuit,strong coal seam reflection,sparse representation,overcomplete dictionary,reservoir prediction,fluid identification
