Random medium 2-D modeling and its wavefield analysis
Yin Xue-xin1,2, Liu Yang1,2
1. State Key Lab of Petroleum Resources and Prospecting, China University of Petroleum(Beijing), Beijing 102249, China;
2. CNPC Key Lab of Geophysical Prospecting, China University of Petroleum(Beijing), Beijing 102249, China
Abstract:With the staggered-grid finite-difference forward modeling of wave equation,we simulate seismic wave propagation in 2-D elastic random medium,obtain seismograms and snapshots of the propagation of spherical wave,and zero offset records of plane wave.In order to study wave field characteristics in 2-D elastic random medium,we divide the records of plane wave into three different time segments:direct wave segment,scattered wave segment and reflected wave segment.And we calculate three statistical characteristic values of three different time segments:relative value of wave field energy,dominant frequency and bandwidth.By studying the relationship between the three statistical characteristic values and autocorrelation length,roughness factor and disturbance standard deviation of the random medium model,we get the following conclusions:with the changes of autocorrelation length,the relative value of wave field energy of direct wave,scattered wave and reflected wave changes significantly.The dominant frequency and bandwidth of direct wave have little effect by these factors.The dominant frequency of scattered wave is mainly affected by the autocorrelation length.However,the bandwidth of scattered wave is very narrow,and has little effect of the factors.The dominant frequency of reflected wave changes significantly versus the factors such as autocorrelation length,roughness factor and disturbance standard deviation,and the bandwidth of the reflected wave is mainly affected by the standard deviation of disturbances.
殷学鑫, 刘洋. 二维随机介质模型正演模拟及其波场分析[J]. 石油地球物理勘探, 2011, 46(6): 862-872.
YIN Xue-Xin, LIU Yang. Random medium 2-D modeling and its wavefield analysis. OGP, 2011, 46(6): 862-872.