Presentation of a fusion model derived from two rock physics models using sugeno fuzzy integral method in one of the southwestern oilfields of Iran

Summary Using rock physics models, it is possible to simulate the reservoir more precisely and as a result, the risk of exploration and production of oil and gas will be reduced significantly. In this study, three models of Self-Consistent-Gassmann, Xu-Payne and Xu-White model was investigated in a two wells in a carbonate reservoir in southwest of Iran. Then, two fused model was proposed to improve the accuracy and improve the efficiency by using the Sugeno fuzzy integral fusion method and Simple Additive Weighting (SAW) Model, respectively. The compressional wave velocity and shear wave velocity were estimated using 5 mentioned models. The results show that in Xu-White and Sugeno fuzzy integral models, the estimation of compressional and shear velocity in well A have the lowest (79 and 81) and the highest correlation coefficient (99 and 98) with real data, respectively. This indicate that the Sugeno fused model is the best estimate. Introduction Since the seismic reservoir characterization have a very important role in all stages of exploration up to the development and production of hydrocarbon reservoirs, it is important to identify the relationship between reservoir properties and their elastic behavior, using rock physics model. In order to improve the rock physics models, researchers proposed different methods, which in this study Sugeno fuzzy integral fusion method has been used. Methodology and Approaches The study of the elastic properties of rock physics on carbonate rock was carried out through of Self-Consistent-Gassmann, Xu-Payne and Xu-White rock physics models. All these models were built to derive optimal elastic properties to obtain reliable estimates of compressional wave velocity, shear wave velocity. The main step consisted of modeling each of the seismic rock properties over a specified porosity, pore space system and hydrocarbon type. At the end, these two models are fused by the Sugeno fuzzy integral fusion model and SAW model. All the models have been evaluated by measured (observed) data. Results and Conclusions Three models of Self-Consistent-Gassmann, Xu-Payne and Xu-White rock physics were evaluated and compared using petrophysical and geological data, in a carbonate reservoir of an Iranian oil field. By examining the results of compressional and shear wave velocity estimation using two fusion methods (SAW and Sugeno) and three models of rock physics, it is determined that the methods and models used for the studied carbonate reservoir have given a satisfactory result, but the Sugeno fusion model has improved the results. The reason for this could be related to the use of optimization algorithms in the Sugeno.