Multiple-Point Simulation Applied to Uncertainty Analysis of Reservoirs Related to High Sinuosity Fluvial Systems: Mina El Carmen Formation, San Jorge Gulf Basin, Argentina*

A comparative study of several stochastic si mulation methods was performed in the reser voirs of the Upper Cretaceous Mina El Ca rmen Formation, in Diadema Field, located in the north flank San Jorge Gulf basin, Argentin a. The reservoirs belong to a meandering fluvial system showing high variability in thickness, ch annel width (less than well separation dist ance) and sinuosity parameters. The study c ompared the results of 30 realizations using Sequential Gaussi an Simulation, Sequential Indicator Simula tion, Object-Based and Multiple-point Seque ntial simulations (MPS) performed over the same facies data. The channe l probability three-dimensional models derived from the simula tions show a better and more realistic respons e of multiple-point methods over the previously widely used simulation methods. The SNESIM alg orithm was selected from the MPS methods available to simulate channel-fl ood plain facies. The model used to guide the MPS simulation was built using a current high-sinuosity fluvial system, the Sanboronbom River, located in Buenos Aires province, Argentina. The training model w as built by digitizing fluvial facies using sa tellite imagery and converted to ASCII format to be used in the SGems public software. The au thors believe that the Cretaceous Mina El Carmen Formation was deposited in a low sl ope environment similar to the ri ver used in the training mode l. After the realizations, the MPS probability model s hows channels with high sinuos ity, variable width, directi on changes and different siz es on the same stratigraphic level. These shapes were im possible to reproduce with the other simula tion methods mentioned above. Moreover, a good appraisal of a five-well forecast was made using the MPS probability model. It is concluded that the multiple-point method is most approp riate to estimate the uncertainty of high sinuosity fluvial syst ems with channel width less then 300 m in av erage, like the Mina El Carmen Format ion channels.