Permeability Distribution Estimation Based on Semi-Analytical Reservoir Simulator

Estimation of rock permeability distribution can be realized by automatic history matching production data. The process of automatic history matching involves the minimization of an objective function which usually includes the sum of data mismatch part as well as the sum of prior model mismatch part. For our semi-analytical simulator, the choice of optimization algorithms to minimize the objective function becomes of vital importance. For our simulator, we considered both gradient based methods and non-gradient based methods. Gradient based algorithms have the big advantage of much faster convergence rate over non-gradient based algorithms. It is illustrated in this study that application of gradient based methods is not practical for this simulator. Among the non-gradient based methods, we choose particle swarm optimization. For this algorithm, reservoir simulator can be treated as a black box. It is easy to implement and be transferred to another simulator within just a few hours. However, for gradient based algorithms, a set of completely different gradient equations are required, whereas greatest advantage of particle swarm optimization is its fast convergence rate at the beginning stage. Three examples are presented to show application of particle swarm optimization in automatic history matching based on synthetic production data. The first example simulates a high permeability channel existing in a relatively lower permeability formation. The second example simulates a formation with gradual changing permeability distribution. The third example represents a formation with sweet spot. The permeability of central part is higher compared to neighbouring area. Estimated permeability distributions have shown that the general permeability trends of these three examples can be caught. At the same time, predictions using estimated permeability field have a very good match with synthetic production history. As such, particle swarm optimization has been introduced and successfully applied to do automatic history matching in our semi-analytical simulator. Uncertainties associated with permeability distribution estimations are reduced significantly.

Name thesis:degree_name

Master of Applied Science (MASc)

Level thesis:degree_level

Master's

Discipline thesis:degree_discipline

Engineering - Petroleum Systems

Grantor dc:publisher

Faculty of Graduate Studies and Research, University of Regina

Year dc:date.issued

2015

Author dc:creator

• Chen, Shuai

Advisor dc:contributor.advisor

• Zhao, Gang

Committee members dc:contributor.committeemember

• Jin, Yee-Chung
• Zeng, Fanhua (Bill)

Language dc:language.iso

en

DOI

https://doi.org/10.82465/3961

OAI identifier oai:identifier

oai:uregina.scholaris.ca:10294/6822