Chen, Yangkang (University of Texas–Austin) | Xiang, Kui (China University of Petroleum–Beijing) | Chen, Hanming (China University of Petroleum–Beijing) | Chen, Xiaohong (China University of Petroleum–Beijing)
Full waveform inversion (FWI) is a promising technique for inverting a high-resolution subsurface velocity model. The success of FWI highly depends on a fairly well initial velocity model. We propose a method for building a remarkable initial velocity model that can be put into the FWI framework for inverting nearly perfect velocity structure. We use a well log interpolated velocity model as a high-fidelity initial model for the subsequent FWI. The interpolation problem is solved via a least-squares method with a structural regularization. In order to obtain the geological structure of subsurface reflectors, an initial reverse time migration (RTM) with a fairly realistic initial velocity model is used to roughly calculate the local slope of subsurface structure. The well log interpolated initial velocity model can be very close to the true velocity while having small velocity anomaly or over-smoothing caused by the imperfect velocity interpolation, which however can be compensated during the subsequent FWI iterations. Regarding the field deployment, we suggest that future drilling should be seismic-oriented, which can help fully utilize the well logs for building initial subsurface velocity model and will facilitate a wide application of the proposed methodology.
Presentation Date: Wednesday, October 19, 2016
Start Time: 4:25:00 PM
Presentation Type: ORAL