Multiscale gradient computation for flow in heterogeneous porous media

JOURNAL OF COMPUTATIONAL PHYSICS

卷:336

Article

de Moraes, Rafael J.^1,2  Rodrigues, Jose R. P.²  Hajibeygi, Hadi¹  Jansen, Jan Dirk¹ 

[1] Delft Univ Technol, Fac Civil Engn & Geosci, Dept Geosci & Engn, POB 5048, NL-2600 Delft, Netherlands

[2] CENPES, Petrobras Res & Dev Ctr, Av Hordcio Macedo 950,Cidade Univ, BR-21941915 Rio De Janeiro, RJ, Brazil

关键词: Gradient-based optimization;    Multiscale methods;    Direct method;    Adjoint method;    Automatic differentiation;   

DOI  :  10.1016/j.jcp.2017.02.024

来源: Elsevier

【 摘 要 】

An efficient multiscale (MS) gradient computation method for subsurface flow management and optimization is introduced. The general, algebraic framework allows for the calculation of gradients using both the Direct and Adjoint derivative methods. The framework also allows for the utilization of any MS formulation that can be algebraically expressed in terms of a restriction and a prolongation operator. This is achieved via an implicit differentiation formulation. The approach favors algorithms for multiplying the sensitivity matrix and its transpose with arbitrary vectors. This provides a flexible way of computing gradients in a form suitable for any given gradient-based optimization algorithm. No assumption w.r.t. the nature of the problem or specific optimization parameters is made. Therefore, the framework can be applied to any gradient-based study. In the implementation, extra partial derivative information required by the gradient computation is computed via automatic differentiation. A detailed utilization of the framework using the MS Finite Volume (MSFV) simulation technique is presented. Numerical experiments are performed to demonstrate the accuracy of the method compared to a fine-scale simulator. In addition, an asymptotic analysis is presented to provide an estimate of its computational complexity. The investigations show that the presented method casts an accurate and efficient MS gradient computation strategy that can be successfully utilized in next-generation reservoir management studies. (C) 2017 Elsevier Inc. All rights reserved.

【 授权许可】

Free