Ensemble based multi-objective production optimization of smart wells

Ensemble based multi-objective production optimization of smart wells

Fonseca, R.M.
Leeuwenburgh, O.
Jansen, J.D.

Civil Engineering and Geosciences

Geoscience & Engineering

2012-12-31

In a recent study two hierarchical multi-objective methods were suggested to include short-term targets in life-cycle production optimization. However this previous study has two limitations: 1) the adjoint formulation is used to obtain gradient information, requiring simulator source code access and an extensive implementation effort, and 2) one of the two proposed methods relies on the Hessian matrix which is obtained by a computationally expensive method. In order to overcome the first of these limitations, we used ensemble-based optimization (EnOpt). EnOpt does not require source code access and is relatively easy to implement. To address the second limitation, we used the BFGS algorithm to obtain an approximation of the Hessian matrix. We performed experiments in which a water flood was optimized in a geologically realistic multi-layer sector model. The controls were inflow control valve settings at predefined time intervals. Undiscounted Net Present V lue (NPV) and highly discounted NPV were the longterm and short-term objective functions used. We obtained an increase of approximately 14% in the secondary objective for a decrease of only 0.2-0.5% in the primary objective. The study demonstrates that ensemble-based multi-objective optimization can achieve results of practical value in a computationally efficient manner.

http://resolver.tudelft.nl/uuid:84edb715-b28f-40fc-89d6-267db6449084

EAGE

ECMOR 13th European conference on the mathematics of oil recovery, Biarritz, 10-13 Sept., 2012

Institutional Repository

conference paper

(c) Delft University of Technology