Xwfd Preserved‐Amplitude Migration with Dual‐Complexity

Abstract

Oil and gas exploration is turning to the areas with irregular topography and complex geologic structures. Prestack depth migration turns out to be a valid way to deal with irregular topography and complex geologic structures. "Wave field downward continuation" based on accumulating step by step is a valid way to solve the problem of irregular surface migration. Xwfd pre-stack migration based on wave equation has strong adaptability to the medium which has strongly variable transverse velocity and it can be used for migration with dual-complexity. Similar to other conventional migration, it makes just continuation of phase and does nothing to the amplitude. We derived the preserved-amplitude Xwfd one-way wave equation operator and added the error compensation caused when solving the wave equation. Based on the Xwfd error compensation preservedamplitude operator, we use the method of "wave field downward continuation" to process the dual-complexity model and real seismic data. The impulse response test and results of the prestack depth migration for model and real seismic data show that the method is an effective tool for dual-complexity. The error compensation can be done during several continuation steps, compared to conventional Finite Difference Fourier (ffd) it has better migration quality.

Preserved amplitude migration based on the one way wave equation in the angle domain

“…Liu et al (2007) proposed detailed deductions about the preserved amplitude Fourier finite difference method based on the one way equation. Ye et al (2008) proposed preserved amplitude migration for irregular surface areas. In the fi eld of preserved amplitude prestack time migration, Zhang and Liu (2008) proposed a method to perform preserved amplitude pre-stack time migration for anisotropic converted waves and Wang et al (2008) used the preserved amplitude pre-stack time migration of plane waves to do AVA analysis, both of which showed an improved amplitude fi delity.…”

Elastic Wave Modeling and Pre‐stack Reverse Time Migration of Irregular Free‐surface Based on Layered Mapping Method

“…In the maturing oil fields and oil blocks, the focus of seismic exploration has changed from simple structures to complex and hidden lithologic reservoirs and the regions that haven't been explored, especially in the irregular surface regions. Dramatic irregular surface brings serious influence on seismic data acquisition and processing, so geophysical scholars have proposed a series of methods to overcome the problems (Li et al, 2007;Ye et al, 2008;Liu et al, 2010;Zhang et al 2012). Now there are two strategies to treat irregular surface: the first is to correct the surface wave field (Berryhill, 1979(Berryhill, , 1984Li et al 2001); the second is to implement deep migration for irregular surface Yang et al, 2007;Lei et al, 2012).…”