Optimal rate allocation for production and injection wells in an oil and gas field for enhanced profitability

Optimal rate allocation for production and injection wells in an oil and gas field for enhanced profitability

Crude oil

Optimization

Profitability

Process control

Oil fields

Petroleum reservoirs

Hydrocarbon refining

Nonlinear programming

Pipeline processing systems

MATLAB

Secondary recovery

Injection (oil wells)

An oil and gas field requires careful operational planning and management via production optimization for increased recovery and long-term project profitability. This article addresses the challenge of production optimization in a field undergoing secondary recovery by water flooding. The field operates with limited processing capacity at the surface separators, pipeline pressure constraints, and water injection constraints

an economic indicator (net present value, NPV) is used as the objective function. The formulated optimization framework adequately integrates slow-paced subsurface dynamics using reservoir simulation, and fast-paced surface dynamics using sophisticated multiphase flow simulation in the upstream facilities. Optimization of this holistic long-term model is made possible by developing accurate second-order polynomial proxy models at each time step. The resulting formulation is solved as a nonlinear program using commercially available solvers. A comparative analysis is performed using MATLAB's fmincon solver and the IPOPT solver for their robustness, speed, and convergence stability in solving the proposed problem. By implementing two synthetic case studies, our mathematical programming approach determines the optimal production and injection rates of all wells and further demonstrates considerable improvement to the NPV obtained by simultaneously applying the tools of streamline, reservoir, and surface facility simulation for well rate allocation via systematic NLP optimization. 2019 American Institute of Chemical Engineers

65

AIChE Journal

2019

Epelle, Emmanuel I.

Gerogiorgis, Dimitrios I.

journalArticle

11541

10.1002/aic.16592