scholarly journals Reservoir fluid production optimization to sustain net-present value (NPV) using gradient-based Quasi-Newton method

2021 ◽  
Vol 1876 (1) ◽  
pp. 012017
Author(s):  
C Salim ◽  
S M Wahjudhi ◽  
Mariyanto
2021 ◽  
Author(s):  
Tsubasa Onishi ◽  
Hongquan Chen ◽  
Jiang Xie ◽  
Shusei Tanaka ◽  
Dongjae Kam ◽  
...  

Abstract Streamline-based methods have proven to be effective for various subsurface flow and transport modeling problems. However, the applications are limited in dual-porosity and dual-permeability (DPDK) system due to the difficulty in describing interactions between matrix and fracture during streamline tracing. In this work, we present a robust streamline tracing algorithm for DPDK models and apply the new algorithm to rate allocation optimization in a waterflood reservoir. In the proposed method, streamlines are traced in both fracture and matrix domains. The inter-fluxes between fracture and matrix are described by switching streamlines from one domain to another using a probability computed based on the inter-fluxes. The approach is fundamentally similar to the existing streamline tracing technique and can be utilized in streamline-assisted applications, such as flow diagnostics, history matching, and production optimization. The proposed method is benchmarked with a finite-volume based approach where grid-based time-of-flight was obtained by solving the stationary transport equation. We first validated our method using simple examples. Visual time-of-flight comparisons as well as tracer concentration and allocation factors at wells show good agreement. Next, we applied the proposed method to field scale models to demonstrate the robustness. The results show that our method offers reduced numerical artifacts and better represents reservoir heterogeneity and well connectivity with sub-grid resolutions. The proposed method is then used for rate allocation optimization in DPDK models. A streamline-based gradient free algorithm is used to optimize net present value by adjusting both injection and production well rates under operational constraints. The results show that the optimized schedule offers significant improvement in recovery factor, net present value, and sweep efficiency compared to the base scenario using equal rate injection and production. The optimization algorithm is computationally efficient as it requires only a few forward reservoir simulations.


2020 ◽  
Vol 24 (3) ◽  
pp. 1087-1100
Author(s):  
Eugênio Libório Feitosa Fortaleza ◽  
Emanuel Pereira Barroso Neto ◽  
Marco Emílio Rodrigues Miranda

Author(s):  
S. Indrapriyadarsini ◽  
Shahrzad Mahboubi ◽  
Hiroshi Ninomiya ◽  
Takeshi Kamio ◽  
Hideki Asai

Gradient based methods are popularly used in training neural networks and can be broadly categorized into first and second order methods. Second order methods have shown to have better convergence compared to first order methods, especially in solving highly nonlinear problems. The BFGS quasi-Newton method is the most commonly studied second order method for neural network training. Recent methods have shown to speed up the convergence of the BFGS method using the Nesterov’s acclerated gradient and momentum terms. The SR1 quasi-Newton method though less commonly used in training neural networks, are known to have interesting properties and provide good Hessian approximations when used with a trust-region approach. Thus, this paper aims to investigate accelerating the Symmetric Rank-1 (SR1) quasi-Newton method with the Nesterov’s gradient for training neural networks and briefly discuss its convergence. The performance of the proposed method is evaluated on a function approximation and image classification problem.


Author(s):  
S. Indrapriyadarsini ◽  
Shahrzad Mahboubi ◽  
Hiroshi Ninomiya ◽  
Takeshi Kamio ◽  
Hideki Asai

Gradient based methods are popularly used in training neural networks and can be broadly categorized into first and second order methods. Second order methods have shown to have better convergence compared to first order methods, especially in solving highly nonlinear problems. The BFGS quasi-Newton method is the most commonly studied second order method for neural network training. Recent methods have shown to speed up the convergence of the BFGS method using the Nesterov’s acclerated gradient and momentum terms. The SR1 quasi-Newton method though less commonly used in training neural networks, are known to have interesting properties and provide good Hessian approximations when used with a trust-region approach. Thus, this paper aims to investigate accelerating the Symmetric Rank-1 (SR1) quasi-Newton method with the Nesterov’s gradient for training neural networks and briefly discuss its convergence. The performance of the proposed method is evaluated on a function approximation and image classification problem.


SPE Journal ◽  
2012 ◽  
Vol 17 (03) ◽  
pp. 849-864 ◽  
Author(s):  
C.. Chen ◽  
G.. Li ◽  
A.C.. C. Reynolds

Summary In this paper, we develop an efficient algorithm for production optimization under linear and nonlinear constraints and an uncertain reservoir description. The linear and nonlinear constraints are incorporated into the objective function using the augmented Lagrangian method, and the bound constraints are enforced using a gradient-projection trust-region method. Robust long-term optimization maximizes the expected life-cycle net present value (NPV) over a set of geological models, which represent the uncertainty in reservoir description. Because the life-cycle optimal controls may be in conflict with the operator's objective of maximizing short-time production, the method is adapted to maximize the expectation of short-term NPV over the next 1 or 2 years subject to the constraint that the life-cycle NPV will not be substantially decreased. The technique is applied to synthetic reservoir problems to demonstrate its efficiency and robustness. Experiments show that the field cannot always achieve the optimal NPV using the optimal well controls obtained on the basis of a single but uncertain reservoir model, whereas the application of robust optimization reduces this risk significantly. Experimental results also show that robust sequential optimization on each short-term period is not able to achieve an expected life-cycle NPV as high as that obtained with robust long-term optimization.


Algorithms ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 6
Author(s):  
S. Indrapriyadarsini ◽  
Shahrzad Mahboubi ◽  
Hiroshi Ninomiya ◽  
Takeshi Kamio ◽  
Hideki Asai

Gradient-based methods are popularly used in training neural networks and can be broadly categorized into first and second order methods. Second order methods have shown to have better convergence compared to first order methods, especially in solving highly nonlinear problems. The BFGS quasi-Newton method is the most commonly studied second order method for neural network training. Recent methods have been shown to speed up the convergence of the BFGS method using the Nesterov’s acclerated gradient and momentum terms. The SR1 quasi-Newton method, though less commonly used in training neural networks, is known to have interesting properties and provide good Hessian approximations when used with a trust-region approach. Thus, this paper aims to investigate accelerating the Symmetric Rank-1 (SR1) quasi-Newton method with the Nesterov’s gradient for training neural networks, and to briefly discuss its convergence. The performance of the proposed method is evaluated on a function approximation and image classification problem.


2018 ◽  
Vol 27 (11) ◽  
pp. 1850167 ◽  
Author(s):  
Lingfei Xu ◽  
Hui Zhao ◽  
Ying Li ◽  
Lin Cao ◽  
Xiaoqing Xie ◽  
...  

Aiming at optimizing polymer flooding, we establish an optimal control model of polymer flooding, which has an objective function of the net present value (NPV) involving the effect of polymer injection. An improved Monte Carlo gradient approximation (MCGA) algorithm, based on the idea of the ensemble-based optimization (EnOpt) scheme to solve the problem of strongly fluctuating perturbation gradients, is proposed by introducing the covariance matrix of the control vectors to filter and smooth the searching direction. A synthetic heterogeneous reservoir model is built to test the performance of the algorithms including the improved MCGA, standard MCGA and finite difference stochastic approximation (FDSA) algorithm. For the results, the improved MCGA gets closer to the optimal NPV of FDSA than the standard algorithm, and shows the high efficiency of saving calculation time compared with the FDSA. The value of NPV increases more than 20% for the improved algorithm, and the optimal production rates, injection rates, polymer concentrations, polymer slug sizes are obtained simultaneously. This paper subsequently discusses the influence of different time step sizes and oil prices. It can be concluded that moderate step size and relatively low oil price are applicable. Finally, an actual block application of the improved MCGA shows a 11.3% increase of NPV and a 6.5% increase of field oil production total (FOPT), showing the feasibility in optimizing real reservoirs.


2020 ◽  
Vol 38 (6) ◽  
pp. 2356-2369
Author(s):  
Yinfei Ma ◽  
Anfeng Shi ◽  
Xiaohong Wang ◽  
Baoguo Tan ◽  
Hongxia Sun

The adjustment and control of the water injection rate is a commonly used method for increasing the cumulative oil production of waterflooded reservoirs. This article studies the production optimization problem under the condition of a fixed total water injection rate. The production process is divided into several segments. Considering the correlation between the segment’s time intervals and the well’s injection rate distribution, a simultaneous optimization of both segmented time and injection rate is proposed for enhancing net present value. Both empirical simulations and field application demonstrate that the suggested methods produce the highest increase in net present value – of approximately 13% and 10%, respectively – and significantly improve water flooding efficiency compared to other conventional schemes, such as segmented oil production optimization, cumulative oil production optimization and Bang-Bang control. The proposed methods under a 2-segment division increase oil production efficiency and greatly reduce adjustment costs.


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