Well ties with log synthetic seismogram based on prestack wavefields simulation

Key words:  synthetic seismogram  well ties  convolution model  wavefield simulation  reflectivity method  multiples

Abstract:

The effects of multiples, converted waves and the processing procedure on well ties were not taken into account in conventional well ties method. In order to decrease the differences of wavefield characteristic between log synthetic seismogram and nearby well seismic trace, and improve the reliability of well ties, a new well ties method based on prestack wavefield simulation was proposed. Firstly, the well log was edited and the wavelet was extracted by conventional method. Secondly, the common reflection point gather located at the well was simulated by the reflectivity method. Thirdly, normal time difference correction and stack were applied to the simulated common reflection point gather. Finally, the stack trace was used as synthetic seismogram to calibrate the seismic reflections for well ties. The results show that the consistency of synthetic seismogram and well nearby traces was improved, and the reliability of well ties was enhanced by using the new method.