Gaussian Beam In Engineering Geophysical Applications And Research

Numerical simulation method of the seismic wavefield has important status in seismic data acquisition, processing and interpretation, which is also an important tool in seismic prospecting. First of all, the method of Gaussian beam seismic wavefield modelling, which was developed in recent years. This method simultaneously thinks about the characteristics of both kinematics and dynamics, and applies to complicated non-uniform media model, and also analyzes absorptive capability of media, and attained good effect on caustic field, critical zone and dark region. This method has the advantages of high accuracy as finite-difference, and high computing efficiency and little requirement of computer capacity as general ray tracing method.Then, the main task and characteristics of engineering geophysical exploration are introduced, for example, most of exploration objects are shallow and small, probing depth is from tens of centimeters to tens of meters. So it is required to get high-resolution(compared with deep petroleum and natural gas exploration) and get high precision interpretation. On one hand, Gaussian beam modelling has often successfully applied to deep petroleum and natual gas exploration, on the other hand, there is no one paper about application to engineering geophysical exploration by now.With the fast development of actual production, the author designed and realized the Gaussian beam modelling simulation system, which includes many modules, for example, it can structure stratum, and constitute velocity model quickly and exactly, and adjust and modify model flexibly, get over many difficulites such as reading data artificially, time consuming, low precision, hard to adjust and modify models and hard to master for beginner. This system is very flexible and convenient, can computer synthetic seismograms of 2-D P and P-SV waves, including VSP record, common shot point record and seismic stacked section, in complex inhomogeneous media. Theoretical and real model tests show the success of the method.Combined with the characteristics of engineering geophysical exploration, and studied how to improve exploration resolution both theoretically and experimentally, and simulatively researched on shallow complex structure wavefield, attained concerned technology and parameters about how to ensure high precision and high resolution, and attained good applied effect by having computed a plenty of simulative experiments and factual materials. We can foresee that it is promising of Gaussian beam modelling simulation technology to apply to engineering geophysical exploration by persistent exploring and study.