1. School of Earth and Space Sciences, Peking Universitv, Beijing 100871, China;
2. Research Institute of Exploration and Development, Liaohe Oilfield, PetroChina, Panjin, Liaoning 124010, China
Abstract:Aiming at the largely existing thin interbed reservoir in real exploration,a thin interbed model is utilized,which has two thin sand beds that are thinner than tuning thickness and are separated by a thin shale bed.Each thin sand bed is treated as a whole unit,and the resolution between the two beds with varying thickness ratios is analyzed.In this study,90°-phase Ricker wavelet is used to generate the composite waveform,which allows the composite waveform of a bed with opposite polarity interfaces of equal amplitude to be symmetrical and the bed information to be better reflected. The analysis of bed resolution is based on either Rayleigh's criterion or Amplitude versus Frequency(AVF).A linear relation between predominant period and the thickness of thin sandstone bed is acquired when the thickness of shale bed is fixed. The trends could be different for different thickness ratios.The result shows that the bed resolution can reach much less than λ/4.When applying AVF to a multilayer thin interbed model,the trend of resolution can have a linear fit with the trend result of simple two bed model.