Optimal Difference Method Research And Application

Since near 20 years, along with state economy's swift development, all have increased day by day to the energy demand. Thus is also getting higher and higher to each kind of exploration and the explanation method request. Is specially higher to petroleum prospecting's principal means seismic survey request. The earthquake numerical simulation technology is simulates the earthquake wave one kind of numerical analysis technology which disseminates in the medium. It holds the influential role in the seismic survey each working stage. The high accuracy, the high velocity, the low consumption numerical simulation receives each oil field, research institute's welcome especially. In view of this question, this article has studied the FCT best difference method, and applies it the elastic wave to develop in the simulation.The optimal-difference is a fast difference. It introduces the optimal difference operator in the finite-difference foundations. The optimal-operator is designed by minimizing the corresponding peak relative error in group velocity.This article in the analysis best difference method frequency dispersion question's foundation, proposed the use flux transmission adjustment method (FCT) processing value frequency dispersion, in is practical is developing in the simulation the effect to be good. And system's inferential reasoning optimization flux transmission adjustment method, its method computation time-consuming few, the precision is high. The process main process includes: 1.computation equation solution. Leads the best difference method, and calculates the result, then carries on processing to the free surface and the boundary as well as the corner. 2. smooth equation solution. First calculates the diffuse reflection flux, revises the difference equation through the diffusion flux the solution (i.e. smooth equation solution). Because this kind of smooth processing is to calculates in the region each mesh point implementation, thus the certain extent suppressed the real fluctuation, creates the oscillation amplitude precision the partial losses. 3.counter-diffusion processing. Because the diffusion is realizes by the conservation way, namely at any time when any spot removes part of wave fields, causes the energy the drop, must have same energy Canada to return to the identical position. Therefore, once has the diffusion, must in the place which any does not need to diffuse introduce the counter-diffusion to counter-balance the diffusion, enables the real wave field to restore. Therefore diffuses to Xie Zuofan revises, is more complex than the diffusion computation, usually is realizes through the misalignment partial search.Simultaneously in the article also has carried on the analysis to the center of origin as well as the boundary absorption condition. and detailed discussion FCT best difference method, in the elastic wave is developing in the simulation the application. The difference is carries on the displacement - stress elastic dynamic equation. Realizes the elastic wave with this method to develop the simulation, so long as the operator half length takes 4-6, each wave length takes 3 sampling points then to obtain the precision very high wave field value. When solution uses that kind of staggered-mesh technology which similar Virieux uses, calculates the different wave field quantity on the different mesh point. But because the model size is limited, produces the disturbance wave field uses the Higdon boundary to absorb the condition. This kind of boundary condition is with some operator combination the boundary reflection absorption, simultaneously has solved four vertex problems, and identical formula in solution different dimension question time does not need to make the revision.Finally in carries on the two-dimensional geological modelling and the FCT best method of difference is developing the method fundamental research in the foundation, this article has designed take three constructions as a foundation, is developing the software architecture take the network database as the central distributional two-dimensional geological modelling and the FCT best method of difference, and has realized the completely proprietary intellectual property rights software product based on Qt, through many model pilot calculations indicated that this software function is complete, the movement has the very good application and the promoted prospect stably. By the study of two-dimensional geological modeling.