The Research Of 2-D Seismic Forward Modeling Method

Seismic forward modeling is the analysis basis of seismic data acquisition, processing and interpretation, and can provide theoretical foundation and scientific assessment for seismic data acquisition, processing and interpretation. By seismic forward modeling, we can check the rationality of design, and the reliability of the results of processing and interpretation, and the validity of inversion method and results.The mostly research methods of forward modeling are ray tracing method and wave equation method. Ray tracing method is based on geometrical optics. Under the condition of high frequency approximation, the main energy of seismic wave spreads along the ray track, ray tracing method has velocity Excellency, and the travel time is nicety.Wave equation theory is used to simulate the spread of seismic wave, can keep the kinematics and dynamic character of seismic wave, and also be able to keep the dynamic character. Finite difference method is a sort of numerical method, based on difference theory. Finite difference method is a fast and available approach to solve wave equation, can adapt the drastic changes of the underground media, moreover the intricacy of model does not impact the operation speed.In this article, basing on analyzing the basic theory and method technology of seismic numerical simulation, and we have researched the 2-D forward modeling, and discussed in detail ray tracing method and wave equation method theory, and discussed their basic algorithms. In 2-D wave equation forward modeling, we have deducted the finite difference operator with different order precision, and discussed stability of difference scheme and boundary condition. On the Windows platform, using C++ language and FORTRAN, and based on the forerunners' research, we have finished the functional modules of two point ray tracing shooting method and four order temporal precision finite difference, and carried out multi-models tests, and proved that the result be right, and the stabilization and adaptability of algorithm. In this article, by geological problems that may be existed in energy prospecting and engineering survey existent, we designed geological models, include fault model, lens model, thin Layer model and cavity model and so on, and proceeded with ray tracing and finite difference method forward modeling, and analyzed and compared the results. The result indicate that these two methods can be processed in the forward modeling of general geological problems, and the finite difference method have better adaptability with intricacy model, higher precision and reliability of results, credibility of dynamic character of seismic wave, and can be approved directly to seismic survey design, data processing and interpretation.