Streamline Tracing and Applications in Dual Porosity Dual Permeability Models

2021 ◽  
Author(s):  
Tsubasa Onishi ◽  
Hongquan Chen ◽  
Jiang Xie ◽  
Shusei Tanaka ◽  
Dongjae Kam ◽  
...  
Keyword(s):  
History Matching ◽  
Net Present Value ◽  
Time Of Flight ◽  
Rate Allocation ◽  
Production Optimization ◽  
Dual Porosity ◽  
Computationally Efficient ◽  
Present Value ◽  
Sweep Efficiency ◽  
Streamline Tracing

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.

Undersaturated Hydrocarbon Reservoir Waterflooding: A simulation Approach to Performance Assessment

2021 ◽  
Author(s):  
Adekunle Tirimisiyu Adeniyi ◽  
Miracle Imwonsa Osatemple ◽  
Abdulwahab Giwa
Keyword(s):  
Oil Recovery ◽  
Net Present Value ◽  
Oil Production ◽  
Base Case ◽  
Present Value ◽  
Sweep Efficiency ◽  
Recovery Method ◽  
Solution Approach ◽  
Hydrocarbon Reservoir

Abstract There are a good numbers of brown hydrocarbon reservoirs, with a substantial amount of bypassed oil. These reservoirs are said to be brown, because a huge chunk of its recoverable oil have been produced. Since a significant number of prominent oil fields are matured and the number of new discoveries is declining, it is imperative to assess performances of waterflooding in such reservoirs; taking an undersaturated reservoir as a case study. It should be recalled that Waterflooding is widely accepted and used as a means of secondary oil recovery method, sometimes after depletion of primary energy sources. The effects of permeability distribution on flood performances is of concerns in this study. The presence of high permeability streaks could lead to an early water breakthrough at the producers, thus reducing the sweep efficiency in the field. A solution approach adopted in this study was reserve water injection. A reverse approach because, a producing well is converted to water injector while water injector well is converted to oil producing well. This optimization method was applied to a waterflood process carried out on a reservoir field developed by a two - spot recovery design in the Niger Delta area of Nigeria that is being used as a case study. Simulation runs were carried out with a commercial reservoir oil simulator. The result showed an increase in oil production with a significant reduction in water-cut. The Net Present Value, NPV, of the project was re-evaluated with present oil production. The results of the waterflood optimization revealed that an increase in the net present value of up to 20% and an increase in cumulative production of up to 27% from the base case was achieved. The cost of produced water treatment for re-injection and rated higher water pump had little impact on the overall project economy. Therefore, it can conclude that changes in well status in wells status in an heterogenous hydrocarbon reservoir will increase oil production.

Production optimization using a modified net present value

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

Optimization of Well Placement Under Time-Dependent Uncertainty

2006 ◽  
Vol 9 (02) ◽  
pp. 135-145 ◽  
Author(s):  
Umut Ozdogan ◽  
Roland N. Horne
Keyword(s):  
History Matching ◽  
Net Present Value ◽  
Optimization Technique ◽  
Production Optimization ◽  
Time Dependent ◽  
Hill Climbing ◽  
Process Data ◽  
Well Placement ◽  
Placement Decisions ◽  
Exploration And Development

Summary Well-placement decisions made during the early stages of exploration and development activities have the capability to improve later placement decisions by providing more information (greater certainty). Therefore, recovery and efficient use of information may add value beyond the amount of oil recovered. This study proposes an approach that emphasizes the value of time-dependent information to achieve better decisions in terms of reduced uncertainty and increased probable net present value (NPV). Unlike previous approaches, well-placement optimization is coupled with recursive probabilistic history-matching steps through the use of the pseudohistory concept. The pseudohistory is defined as the probable (future) response of the reservoir that is generated by a probabilistic forecasting model. To test the results of the proposed approach, an example reservoir was investigated with multiple realizations, all of which match the same production history. The results of this study showed that subsequent well-placement decisions can be improved when probabilistic production profiles obtained from the wells, as they are drilled, are incorporated in the optimization scheme.. Introduction Well placement is one of the important decisions made during the exploration and development phase of projects. Most of the time, the large number of possibilities, constraints on computational resources, and the size of the simulation models limit the number of possible scenarios that may be considered. In these cases, optimization algorithms become extremely valuable in searching for the optimum development scenario. Various approaches have been proposed for production optimization. Bittencourt (1994) optimized the scheduling of a field using the polytope algorithm. Beckner and Song (1995) applied the traveling salesman framework on a well-placement problem, using simulated annealing (SA) to find the optimum locations of the wells. Bittencourt and Horne (1997) hybridized genetic algorithms (GA) with the polytope algorithm and tabu search and referred to this hybrid optimization technique as HGA. HGA was observed to improve the economic forecasts and CPU effort during optimization. Pan and Horne (1998) used kriging as a proxy to the reservoir simulator to decrease the number of simulations. Guyaguler et al. (2000) showed that the number of simulations required to optimize the injector well locations decrease when an HGA was coupled with a kriging proxy. Yeten et al. (2002) coupled GA with hill-climbing methods and an artificial neural network (ANN) proxy to optimize the type, location, and trajectory of nonconventional wells. Guyaguler and Horne (2001) assessed the uncertainty of the well-placement results using utility theory together with multiple realizations of the reservoir. All these approaches considered only the information that was available at the beginning of the optimization process. Data that would become available as the reservoir developed in time was not taken into account.

Robust Constrained Optimization of Short- and Long-Term Net Present Value for Closed-Loop Reservoir Management

SPE Journal ◽  
2012 ◽  
Vol 17 (03) ◽  
pp. 849-864 ◽  
Author(s):  
C.. Chen ◽  
G.. Li ◽  
A.C.. C. Reynolds
Keyword(s):  
Life Cycle ◽  
Net Present Value ◽  
Production Optimization ◽  
Nonlinear Constraints ◽  
Present Value ◽  
Short Term ◽  
Linear And Nonlinear Constraints ◽  
Linear And Nonlinear ◽  
Reservoir Description

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.

Production Optimization of Polymer Flooding Using Improved Monte Carlo Gradient Approximation Algorithm with Constraints

2018 ◽  
Vol 27 (11) ◽  
pp. 1850167 ◽  
Author(s):  
Lingfei Xu ◽  
Hui Zhao ◽  
Ying Li ◽  
Lin Cao ◽  
Xiaoqing Xie ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Net Present Value ◽  
High Efficiency ◽  
Polymer Flooding ◽  
Production Optimization ◽  
Reservoir Model ◽  
Present Value ◽  
Step Size ◽  
Time Step ◽  
Polymer Injection

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.

scholarly journals Developing a new technique for the simultaneous optimization of both segmented time and injection rate for water flooding reservoirs: An analysis of Shengli Oilfield XIN-42 reservoir block

2020 ◽  
Vol 38 (6) ◽  
pp. 2356-2369
Author(s):  
Yinfei Ma ◽  
Anfeng Shi ◽  
Xiaohong Wang ◽  
Baoguo Tan ◽  
Hongxia Sun
Keyword(s):  
Net Present Value ◽  
Water Injection ◽  
Oil Production ◽  
Adjustment Costs ◽  
Injection Rate ◽  
Production Optimization ◽  
Simultaneous Optimization ◽  
Water Flooding ◽  
Present Value ◽  
Oil Production Optimization

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.

ANALISIS KELAYAKAN FINANSIAL INDUSTRI PENGOLAHAN KECAP ANEKA GUNA DI KOTA LANGSA

2017 ◽  
Vol 2 (1) ◽  
pp. 21-30
Author(s):  
Muhammad Jamil ◽  
Januari Frizki Bella
Keyword(s):  
Net Present Value ◽  
Rate Of Return ◽  
Internal Rate Of Return ◽  
Present Value ◽  
Internal Rate

Adapun tujuan dari Penelitian ini adalah untuk mengetahui kelayakan usaha industri pengolahan kecap Aneka Guna apabila dilihat dari segi kelayakan finansial. Penelitian ini menggunakan metode studi kasus. Lokasi penelitian yaitu di Kota Langsa dengan pertimbangan bahwa lokasi tersebut merupakan daerah yang terdapat industri pengolahan kecap asin dan mudah di jangkau oleh penulis. Waktu penelitian dilaksanakan pada Bulan Juni - Oktober 2014. Tenaga kerja yang digunakan berjumlah 27 orang, 20 tenaga kerja pria dan 7 orang tenaga kerja wanita. Jumlah penggunaan tenaga kerja selama 5 tahun sebesar 3759 HKP. Total biaya produksi yang dikeluarkan oleh pengusaha dalam usaha pembuatan kecap didaerah penelitian selama 5 tahun adalah Rp. 2.076.988.000,-. Pendapatan kotor yang diperoleh pengusaha sebesar Rp. 8.199.690.000,- dan pendapan bersih yang diperoleh sebesar Rp. 6.122.702.000,-                 Kota Langsa hanya memiliki 1 pengusaha pengolahan kecap asin dan dijadikan sebagai pengusaha sampel yaitu usaha industri pengolahan kecap asin Aneka Guna. Hasil perhitungan di peroleh Net Present Value (NPV) sebesar Rp. 263.281.290 (lebih besar dari nol), sedangkan Internal Rate of Return (IRR) sebesar 84% lebih besar dari tingkat bunga yang berlaku (D.F. = 18%), sedangkan Net B/C Ratio sebesar 3,27 (lebih dari pada 1) dan Pay Back Priod (PBP) 1 Tahun 6 Bulan (lebih kecil dari umur ekonomis).  

UNIFICATION OF STANDS SELECTION FOR FINAL FELLING IN STRATEGIC AND TACTICAL PLANNING

2015 ◽  
Author(s):  
Ainārs GRĪNVALDS
Keyword(s):  
Strategic Planning ◽  
Net Present Value ◽  
Strategic Plan ◽  
Regression Function ◽  
Tactical Planning ◽  
Present Value ◽  
Black Alder ◽  
Value Maximization ◽  
Annual Changes ◽  
Selection For

The stand selection for cutting in tactical planning should be done according to the same principles like in strategic planning – to maximize net present value. The simple way of how to transfer the net present value maximization principle from strategic planning to tactical planning was created in Sweden. The method is based on annual changes in the net present value by postponing final felling. Forest inventory data and forestry modelling system was used for calculation of changes in net present value for pine, spruce, birch, aspen and black alder stands. And changes in net present value were described by regression function with factors from stand parameters. The regression function allows calculating annual changes in net present value for each stand. And stands with higher decrease in net present value have higher cutting priority. Stands selected for the final felling in strategic plan were compared with the stands selected in tactical plan with two methods, first, by using annual changes in the net present value, second, by traditional planning principles. Stands selected by annual changes in the net present value were similar to stands that were selected for cutting in strategic plan, but stands selected by traditional planning principles – not.

EVALUASI TERHADAP PENGELOLAAN SAMPAH DALAM MENINGKATKAN PELAYANAN ASET DI KOTA PEMATANGSIANTAR

2017 ◽  
Vol 13 (3) ◽  
pp. 240
Author(s):  
Novdin M Sianturi
Keyword(s):  
Net Present Value ◽  
Payback Period ◽  
Rate Of Return ◽  
Cost Ratio ◽  
Internal Rate Of Return ◽  
Present Value ◽  
Benefit Cost Ratio ◽  
Internal Rate ◽  
Benefit Cost

Abstrak: Pengelolaan sampah di Kota Pematangsiantar masih bertumpu pada pendekatan akhir (kumpul-angkut-buang), dengan tingkat pelayanan yang rendah, sehingga untuk meningkatkan pelayanan sampah, perlu dilakukan pemilahan di tempat penampungan sementara (TPS). Penelitian ini bertujuan untuk mengkaji sistem pengelolaan sampah dengan melakukan pemilihan di TPS dapat meningkatkan pelayanan aset persampahan sampai tahun  2015 secara teknis operasional dan dari aspek keuangan. Analisa teknis operasional aset pengelolaan sampah mulai dari pewadahan, pengumpulan dan pengangkutan sedangkan analisa keuangan dan analisa kelayakan menggunakan Net Present Value, Internal Rate of Return, Benefit/Cost Ratio, dan Payback Period. Dari hasil analisa tersebut diperoleh suatu sistem pengelolaan sampah dengan pemilihan di TPS berdasarkan zona pelayanan dengan skala prioritas secara bertahap daritahun 2013-2017, dapat meningkatkan cakupan pelayanan sampah eksisting rata-rata 6,69 %, cakupan pelayanan TPS eksisting rata-rata 8,29 %, dan cakupan pelayanan truk pengangkut sampah eksisting rata-rata 12,03 %. Investasinya layak, diperoleh Net Cashflow pada tahun 2020 sebesar Rp 1.720.242.284,-, NPV suku bunga 15 % bernilai positif, IRR > MARR 15 %,  B/C Ratio > 1, dan PP 4,7 tahun, lebih pendek dari periode investasi 10 tahun. Dari Metode penelitian ini maka pengumpulan data, observasi lapangan dan pengukuran contoh timbulan sampah dengan sampel 4 TPS perumahan yang terlayani pengangkutan.

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