A Wavelet-Based Methodology For Data Integration In Reservoir Modeling

In this paper a new methodology is presented in order to integrate geological information with production history from the wells to perform a better reservoir characterization. It uses the wavelet transform over a history-matched realization of the numerical model. An important characteristic of this procedure is the ability to incorporate new data sets at different resolution scales (core samples, well logs, well tests, seismic data) but in real time as the acquisition comes without needing to perform global adjustments to the model every time that a new source of information is added. The methodology is based on the work proposed by Sahni and Home (2006a), that based on the Haar wavelet allows improving the history-matched geological model through the inclusion of additional geological constraints. The first step of the presented method is to match the production history of the reservoir that will be modeled by means of numerical simulation. Then, the wavelet function that better fits the distribution of the considered properties is selected, by means of the Energy Compaction Ratio (ECR). After performing the wavelet transform, the most sensitive coefficients to the production data are determined. Those that are not significant for the matching can be replaced by new data sources or geostatistical interpolation of the sensitive coefficients (e.g. Sequential Gaussian Simulation). Finally, when the inverse transform is performed, the data set is not only validated by the production history but also by the geological properties. If the wavelet transform is not Haar, an additional benefit is obtained. It is possible to perform downscaling through the interpolation of geological information based on the wavelet function, in the different regions where the data acquisition is difficult or doubtful.<br>This new heuristic methodology has been tested in different reservoir configurations. In this paper we show the results achieved for a test case reservoir with patterns of 4 producers and 2 injectors. This procedure is very helpful in reservoir characterization, data integration and numerical modeling.