The Application Of Pre-stack Time Migration Technology In Coalmine Seismic Exploration

Normal seismic data processing usually uses post-stack migration, however, it just can make reflecting layers return its own position and make coiling wave converge and can't deal with uncommon reflecting points stacking of inclining interfaces. The pre-stack migration technique is one of the effective methods in solving fine velocity analysis and complex structures imaging, at the same time it is also the development tendence of seismic data imaging in our country or overseas in recent years. Compare to pre-stack of deep migration, pre-stack of time migration demand velocity precision is not too much. In complex conformation and velocity vary not too much area, pre-stack of time migration could make complex conformation become nicety of image. Pre-stack of time migration is more important method in practicality.This dissertation introduced the concept and principle of migration, especially pre-stack time migration(PSTM), and discussed different velocity analysis methods in migration, further ascertained the application scope and preconditions of PSTM, and provided some reference for applying PSTM.Using pre-stack time migration and conventional post stack migration, the seismic data were generated by forward modeling on geology model. After comparing and analyzing the seismic profiles in time domain, the conclusion was that the pre-stack time migration had better effect in improving imaging quality of steep dip formation, and it can improve the seismic data processing quality and locate the underground complex structure more precisely.Based on the research of pre-stack time migration of real 3D seismic data, summarized an effective procedure for 3D pre-stack time migration. After comparing the imaging quality and recognition of small faults of pre-stack time migration and conventional post stack migration, the conclusion was that the pre-stack time migration can clearly image the geology structure in time domain, and the fault point can be imaged precisely, it was an advanced seismic imaging technique with great applicability an precision.