Joint interferometric imaging of walkaway VSP data

Abstract

In this paper, we image the subsurface reflectors by interferometric imaging using primary and downgoing first-order free-surface related multiple reflections in walkaway VSP data. By analyzing the stack fold distribution, we find that primary-direct interferometric imaging has a smaller image range, but its stack fold is higher near the well while ghostdirect interferometric imaging is the opposite. We try to solve this problem by the joint interferometric imaging of walkaway VSP data, combining primary-direct interferometric imaging with ghost-direct interferometric imaging. In this way, we can effectively widen the imaging range, simultaneously increase the fold (especially near the well), suppress spurious interference, and improve the image SNR, so that we can get a more credible image. Test results on synthetic walkaway VSP data and field data show that joint interferometric imaging is very effective.

Reservoir time-lapse variations and coda wave interferometry

“…Coda wave interferometry uses the differences before and after small disturbances to detect weak changes in propagation media. Presently, this method has been used to probe the relative location of seismic sources (Snieder and Vrijlandt, 2005;Sato, 1986;Robinson, 1987;Roberts et al, 1992;Qiao et al, 2014;Wang et al, 2010), to monitor rapid temporal changes in volcanoes (Grêt et al, 2005;Wegler, 2004;Ratdomopurdo and Poupinet, 1995), and applied to the time-lapse monitoring of rock properties in the laboratory (Grêt et al, 2006;Weaver and Lobkis, 2000). Snieder et al (2002) used coda wave interferometry to obtain the signal delay and estimated the nonlinear seismic velocity variations.…”

Ambient Noise Seismic Interferometry Through Surface Seismic Data Acquisition vs Zero-Offset Vertical Seismic Profiling (Vsp)

“…Several works are conducted to image flanks using VSP data (Lu et al, 2008;Hornby and Yu et al, 2007;Xiao et al, 2006;Willis et al, 2006). Wang et al (2010) noted that the primary waves and ghosts together can display subsurface reflectors using the walk away VSP data. Matsushima et al (2016) examined the attenuation prediction with the help of zero-offset VSP data.…”