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Geostatistically-consistent History Matching
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, ECMOR XIV - 14th European Conference on the Mathematics of Oil Recovery, Sep 2014, Volume 2014, p.1 - 13
Abstract
History matching of 3D model is a necessary step in reservoir simulation practice. This procedure is tedious and time-consuming despite all the contemporary attempts and achievements in integration of multi-scale, heterogeneous and diverse data during 3D geological model creation. Anyway, matching of a 3D simulation model to dynamic data is often conducted without paying adequate attention to peculiarities of underlying 3D geologic model. Often reservoir engineer modifies model parameters without due regard for geological view of the reservoir concerned and underlying geostatistical information. Consequently there is a huge gap between methods and means used for 3D geological model creation and the way it is utilized in 3D reservoir simulation and history matching. On the other hand, several popular math-based approaches to history matching which try to honor geological concepts of a 3D model by adjusting ensembles of model realizations are still impractical for everyday use in terms of robustness and amount of computational work.
The authors plan to present an approach to automatic history matching of 3D simulation model based on adjustment of parameters of underlying geostatistical model. Namely, range, sill and nugget of a variogram, as well as major and minor directions, could serve as control parameters to be updated, meanwhile strictly honoring static input data. Corresponding derivatives were deduced for all popular forms of variogram models. Objective function gradients are calculated with the aid of modern methods of optimal control theory. Inverse problem is treated with highest possible generality, videlicet facial heterogeneity and variogram anisotropy are assumed taking place. Either parameters of log permeability to porosity relation within each facie or well permeability multipliers are also identified through inverse problem solution. Although the algorithm is implemented in in-house SimMatch reservoir simulation and history matching software, a dedicated Petrel plugin has also been developed to assist integration of the approach in practical 3D modeling and reservoir engineering workflow.
The paper is accompanied with synthetic tests confirming robustness of the proposed method as well as full-field example.