Duan, Peiran (School of Geosciences, China University of Petroleum-East China) | Gu, Bingluo (School of Geosciences, China University of Petroleum-East China) | Li, Zhenchun (School of Geosciences, China University of Petroleum-East China)
Based on the full two-way wave equation for wavefield extrapolation, reverse time migration (RTM) is considered as a powerful imaging technique that avoids the approximation of wave equation, without dip and extreme lateral variation of velocity limitation. However, this algorithm suffers from very expensive computational costs and high storage requirement. In this study, we introduce curvilinear coordinate system such that the depth of the Cartesian coordinate was converted to vertical time domain to overcome oversampling problems at higher speed regions, and derive the 1st order velocity-stress seismic wave equation in vertical time domain. This feature has a more profound effect on the areas with large speed differences, especially in the mid-deep high-speed areas. Besides, we deduce the difference formula of the approximate source wavefield using the optimization operator, and reconstructs the differential-order layer wavefield in the calculation area by storing the optimization operator of each point around each time slice, and uses this optimization operator boundary storage strategy to improve 3D RTM algorithm in vertical time domain. Our RTM algorithm is success in accurately imaging of complex structures and reducing 68.4% of the storage and 35% of the computation times.
Presentation Date: Tuesday, October 16, 2018
Start Time: 1:50:00 PM
Location: 207A (Anaheim Convention Center)
Presentation Type: Oral