The Research And Application Of Sequential Indicator Conditional Method

After Kriging estimation, conditional simulation is developing fast in geostatistics. Geostatistics is an emerging edge discipline which only establishes and develops in the nearly twenty years. It can be said that:" Variation function is the basic tool of geostatistics, and in the basic research on regionalizing spatial distribution of the variables, to choose Kriging method, and achieve a more precise estimate or carry on conditional simulation to the regionalizing variable, is the main purpose of geostatistics which is mathematics geology's independent branch. It generally includes three big basic components: namely the spatial function relevant analysis, Kriging estimation and the conditional simulation. The spatial function relevance analysis is the analysis of the variation and covariance functions, including their definitions and estimation variances, it is the foundation of Kriging estimation and conditional simulation. It is based on the spatial relevance analysis which reflected in the variation function and the covariance function that Kriging estimation and the conditional simulation can develop. Kriging estimation is a method of optimized unbiased estimation, an average estimation, it can only give a single model, relatively conditional simulation can get more than one model, and the differences between the results just reflect uncertainty of the geological variables.Recently, conditional simulation is developing fast in modeling of the reservoir. For the reservoir description is always uncertain and the result of reservoir forecast has several results because the reconnoiter information is incomplete. Conditional simulation, which overcomes the smooth effect of Kriging estimation, not only reappears the relative structure of the reservoir, but also makes the known data to be conditional. So people always use the conditional simulation method to model and forecast the reservoir because conditional simulation can satisfy the description and the analysis of the uncertain character of the reservoir.This paper discusses indicator variation function and indicator model, and the smoothing effect of Kriging estimation can be seen from simulation results, Finally, the sequential conditional method has been applied to reservoir simulation modeling, and provide a wide range of choices to describe the real geological conditions.