Pseudo-offset migration （POM） is a new method for prestack time migration of converted waves that improves on equivalent-offset migration （EOM）. The mapping of POM is different than EOM but the purpose of the two ...Pseudo-offset migration （POM） is a new method for prestack time migration of converted waves that improves on equivalent-offset migration （EOM）. The mapping of POM is different than EOM but the purpose of the two methods is to map the input samples to the common conversion scatter point （CCSP） gathers. This paper introduces the principles of the two migration methods and model parameter sensitivity tests for both POM and EOM. At large offset-to-depth ratios the hyperbolic approximation, the three-term approximation and the double square root （DSR） equation are used to NMO-correct the mapped POM gathers to obtain more accurate migration velocities. These equations were derived and calculated by small pseudo offset. POM is then used to image complex structure and prestack time migration.展开更多
For strata with complex structure and faulting, the conventional horizontal stack method can not provide a high quality image and the conventional DMO technique has low computational efficiency and practicability. Thi...For strata with complex structure and faulting, the conventional horizontal stack method can not provide a high quality image and the conventional DMO technique has low computational efficiency and practicability. This＇article studies a logarithm stretching DMO method in the time domain to accelerate the computational speed as well as improve the image quality. It also covers the processing of physical model and real data using the logarithm stretching DMO algorithms. The logarithm stretching DMO method can produce reflections from faults and implements the in-phase stack of dipping layers and complicated structures better than the conventional horizontal stack method. So this method has better application to thrust-nappe areas.展开更多
基金This work is sponsored by the Nation's Key Scientific & Technologic Projects (2003 BA613-09).
文摘Pseudo-offset migration （POM） is a new method for prestack time migration of converted waves that improves on equivalent-offset migration （EOM）. The mapping of POM is different than EOM but the purpose of the two methods is to map the input samples to the common conversion scatter point （CCSP） gathers. This paper introduces the principles of the two migration methods and model parameter sensitivity tests for both POM and EOM. At large offset-to-depth ratios the hyperbolic approximation, the three-term approximation and the double square root （DSR） equation are used to NMO-correct the mapped POM gathers to obtain more accurate migration velocities. These equations were derived and calculated by small pseudo offset. POM is then used to image complex structure and prestack time migration.
基金This research is sponsored by National 973 Foundation (No. 2001CB209105)
文摘For strata with complex structure and faulting, the conventional horizontal stack method can not provide a high quality image and the conventional DMO technique has low computational efficiency and practicability. This＇article studies a logarithm stretching DMO method in the time domain to accelerate the computational speed as well as improve the image quality. It also covers the processing of physical model and real data using the logarithm stretching DMO algorithms. The logarithm stretching DMO method can produce reflections from faults and implements the in-phase stack of dipping layers and complicated structures better than the conventional horizontal stack method. So this method has better application to thrust-nappe areas.
