Several Decades of Fluid Diversion Evolution, Is There a Good Solution?

2021 ◽  
Author(s):  
Alberto Casero ◽  
Ahmed M. Gomaa
Keyword(s):  
Treatment Success ◽  
Optimal Solution ◽  
Injection Rate ◽  
Testing Procedures ◽  
Well Completion ◽  
Scale Inhibition ◽  
Viscoelastic Surfactants ◽  
Sandstone Formation ◽  
Operational Constraints ◽  
Selection Of

Abstract The success of any matrix treatment depends upon the complete coverage of all zones. Consequently, the selection of the diversion technology is critical for treatment success. While various types of diverting agents are commercially available, the proper selection of optimal diverter depends on many factors, including well completion and history, compatibility with reservoir and treatment fluids, treatment objectives, operational constraints, and safety and environment considerations. The study will cover five major types of non-mechanical diversion technologies considered as potential solutions for offshore deepwater oil reservoirs: dynamic diversion, relative permeability modifiers (RPM), viscoelastic surfactants (VES), particulate diversion, and perforation diversion. All of them, but a dynamic diversion, are based on different chemicals or products to be added to the injected treatment fluid, and occasionally some can be complementary to each other. Given the offshore and deepwater settings, mechanical diversion techniques were not covered in the study, aiming to find a solution that would achieve acceptable diversion while minimizing operational effort, which would enable riser-less intervention and the use of light intervention techniques. This study was driven by the need to effectively stimulate a 500ft of a cased and perforated interval with a permeability of 500 md, and injection rate limited to 16 bpm due to completion limitations. The sandstone formation, with static in situ temperature of 270F, was far beyond the applicability of dynamic diversion and, to achieve the desired full coverage for the planned scale inhibition treatment required and combination with another diverter system was needed. The process applied included compatibility tests, regained permeability tests, and test well trials. Depending on the specific diversion product analyzed the testing procedures were adapted to obtain the information to properly guide to the optimal solution.

Identifying Measurement Invariant Item Sets in Cross-Cultural Settings Using an Automated Item Selection Procedure

Methodology ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 177-188 ◽  
Author(s):  
Martin Schultze ◽  
Michael Eid
Keyword(s):  
Measurement Invariance ◽  
Optimal Solution ◽  
Selection Procedure ◽  
Cross Cultural ◽  
Item Selection ◽  
Ant System ◽  
Item Quality ◽  
Ant System Algorithm ◽  
Selection For ◽  
Selection Of

Abstract. In the construction of scales intended for the use in cross-cultural studies, the selection of items needs to be guided not only by traditional criteria of item quality, but has to take information about the measurement invariance of the scale into account. We present an approach to automated item selection which depicts the process as a combinatorial optimization problem and aims at finding a scale which fulfils predefined target criteria – such as measurement invariance across cultures. The search for an optimal solution is performed using an adaptation of the [Formula: see text] Ant System algorithm. The approach is illustrated using an application to item selection for a personality scale assuming measurement invariance across multiple countries.

scholarly journals Algoritma Elephant Herding Optimization: Permasalahan Multiple Constraints Knapsack 0-1

2018 ◽  
Vol 18 (1) ◽  
pp. 13
Author(s):  
Yulia Dewi Regita ◽  
Kiswara Agung Santoso ◽  
Ahmad Kamsyakawuni
Keyword(s):  
Knapsack Problem ◽  
Simplex Method ◽  
Optimization Problems ◽  
Optimal Solution ◽  
Secondary Data ◽  
Multiple Constraints ◽  
Microsoft Excel ◽  
Storage Media ◽  
Simulation Results ◽  
Selection Of

Optimization problems are often found in everyday life, such as when determining goods to be a limited storage media. This causes the need for the selection of goods in order to obtain profits with the requirements met. This problem in mathematics is usually called a knapsack. Knapsack problem itself has several variations, in this study knapsack type used is multiple constraints knapsack 0-1 which is solved using the Elephant Herding Optimization (EHO) algorithm. The aim of this study is to obtain an optimal solution and study the effectiveness of the algorithm comparing it to the Simplex method in Microsoft Excel. This study uses two data, consisting of primary and secondary data. Based on the results of parameter testing, the proven parameters are nClan, nCi,α,β and MaxGen have a significant effect. The final simulation results have also shown a comparison of the EHO algorithm with the Simplex method having a very small percentage deviation. This shows that the EHO algorithm is effective for completing optimization multiple constraints knapsack 0-1. Keywords: EHO Algorithm, Multiple Constraints Knapsack 0-1 Problem.

scholarly journals Specific aspects of the retrofitting design and seismic assessment of a heritage pedestrian bridge

2020 ◽  
Vol 63 (4) ◽  
pp. 65-77
Author(s):  
Emil Yanev
Keyword(s):  
Optimal Solution ◽  
Investment Project ◽  
Hydroelectric Power Plant ◽  
Normal Operation ◽  
Design Solution ◽  
Original Structure ◽  
Hydroelectric Power ◽  
Pedestrian Bridge ◽  
The Subject ◽  
Selection Of

The purpose of this study is to establish a suitable structural system for the restoration of the destroyed part of the pedestrian bridge, which is a part of a hydrocomplex built along the Arda River (Bulgaria), and to improve the vulnerable details in the original structure, taking into account the seismic hazard on the site. The decision is also dictated by the choice of a construction method that does not interfere the Hydroelectric Power Plant (HPP) that is built along the river with the normal operation of which the subject is connected. The appropriate selection of materials and modelling of the overall behaviour of the old and new parts of the bridge are the basis of the optimal solution for interference with the structure and the possibility of extending its service life. It is also important to preserve the visual unity of the whole structural complex, thus preserving the original appearance and good construction practice from the time they have been built during the middle of the 20th century This design solution is part of an investment project of "Risk Engineering" Ltd.

Analysis for Selection of Tubular Connections for HPHT Gas Well Completion

2018 ◽  
Author(s):  
Jiandong Wang ◽  
Huali Zhang ◽  
Yufei Li ◽  
Dajiang Zhu ◽  
Chuanlei Wang
Keyword(s):  
Gas Well ◽  
Well Completion ◽  
Selection Of

Über einige Probleme der Anwendung der Pfadanalyse – Bemerkungen zu einer Studie über soziokulturelle Determinanten der Fähigkeit zum Role-Taking / On some problems in applying path analysis – Comments on a study of sociocultural determinants of role-taking

1977 ◽  
Vol 6 (1) ◽  
Author(s):  
Wolfgang Jagodzinski ◽  
Michael Zängle
Keyword(s):  
Path Analysis ◽  
Symbolic Interactionism ◽  
Causal Model ◽  
Developmental Approach ◽  
Role Taking ◽  
Testing Procedures ◽  
Recursive Models ◽  
Selection Of Variables ◽  
Selection Of ◽  
Identification Procedures

AbstractThis paper is about a causal model of role-taking recently suggested by BERTRAM and BERTRAM. The model tries to combine aspects of the cognitive-developmental approach as proposed by BRUNER, PIAGET, and WYGOTSKI,and symbolic interactionism as advocated by LINDESMITH and STRAUSS. While the selection of variables is handled rather carefully, the identification and testing procedures may be criticized in three respects: They are tautological because the same equations are used for identifying and testing the model, they are contradictory because identification procedures applicable to recursive models only are applied to a nonrecursive model, and they are fragmentary because only a few although the most important of the possible comparisons of implied and observed correlations are computed. Thus, some of the author’s major conclusions seem not to warranted by the rules of path analysis.

A review of the artificial neural network surrogate modeling in aerodynamic design

2019 ◽  
Vol 233 (16) ◽  
pp. 5863-5872 ◽  
Author(s):  
Gang Sun ◽  
Shuyue Wang
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Design Space ◽  
Optimal Solution ◽  
Surrogate Modeling ◽  
Aerodynamic Design ◽  
Hidden Information ◽  
Data Manipulation ◽  
Artificial Neural ◽  
Selection Of

Artificial neural network surrogate modeling with its economic computational consumption and accurate generalization capabilities offers a feasible approach to aerodynamic design in the field of rapid investigation of design space and optimal solution searching. This paper reviews the basic principle of artificial neural network surrogate modeling in terms of data treatment and configuration setup. A discussion of artificial neural network surrogate modeling is held on different objectives in aerodynamic design applications, various patterns of realization via cutting-edge data technique in numerous optimizations, selection of network topology and types, and other measures for improving modeling. Then, new frontiers of modern artificial neural network surrogate modeling are reviewed with regard to exploiting the hidden information for bringing new perspectives to optimization by exploring new data form and patterns, e.g. quick provision of candidates of better aerodynamic performance via accumulated database instead of random seeding, and envisions of more physical understanding being injected to the data manipulation.

scholarly journals Greedy Algorithm for Minimizing the Cost of Routing Power on a Digital Microgrid

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3076 ◽  
Author(s):  
Zhengqi Jiang ◽  
Vinit Sahasrabudhe ◽  
Ahmed Mohamed ◽  
Haim Grebel ◽  
Roberto Rojas-Cessa
Keyword(s):  
Optimal Solution ◽  
High Complexity ◽  
Distributed Energy ◽  
Optimal Method ◽  
Cost Rate ◽  
Trade Offs ◽  
Lower Complexity ◽  
Cost Paths ◽  
The Cost ◽  
Selection Of

In this paper, we propose the greedy smallest-cost-rate path first (GRASP) algorithm to route power from sources to loads in a digital microgrid (DMG). Routing of power from distributed energy resources (DERs) to loads of a DMG comprises matching loads to DERs and the selection of the smallest-cost-rate path from a load to its supplying DERs. In such a microgrid, one DER may supply power to one or many loads, and one or many DERs may supply the power requested by a load. Because the optimal method is NP-hard, GRASP addresses this high complexity by using heuristics to match sources and loads and to select the smallest-cost-rate paths in the DMG. We compare the cost achieved by GRASP and an optimal method based on integer linear programming on different IEEE test feeders and other test networks. The comparison shows the trade-offs between lowering complexity and achieving optimal-cost paths. The results show that the cost incurred by GRASP approaches that of the optimal solution by small margins. In the adopted networks, GRASP trades its lower complexity for up to 18% higher costs than those achieved by the optimal solution.

Selection of Climatic Design Points for Gas Turbine Power Augmentation

2011 ◽  
Author(s):  
Mustapha Chaker ◽  
Cyrus B. Meher-Homji
Keyword(s):  
Gas Turbine ◽  
Optimal Solution ◽  
Climatic Conditions ◽  
Weather Data ◽  
Climatic Data ◽  
Data Set ◽  
Suggested Approach ◽  
Design Point ◽  
Impact Performance ◽  
Selection Of

There is a widespread interest in the application of gas turbine power augmentation technologies such as evaporative cooling or mechanical chilling in the mechanical drive and power generation markets. Very often, the selection of the design point is based on the use of ASHRAE data or a design point that is in the basis of design for the project. This approach can be detrimental and can result in a non optimal solution. In order to evaluate the benefits of power augmentation, users can use locally collected weather data, or recorded hourly bin data set from databases such as TMY, EWD, and IWS. This paper will cover a suggested approach for the analysis of climatic data for power augmentation applications and show how the selection of the design point can impact performance and economics of the installation. The final selection of the design point depends on the specific application, the revenues generated and installation costs. To the authors’ knowledge, this is the first attempt to treat this topic in a structured analytical manner by comparing available database information with actual climatic conditions.

Application of Taguchi Method to Optimization of Cutting Force and Temperature during Turning of Difficult to Cut Materials

2016 ◽  
Vol 686 ◽  
pp. 114-118 ◽  
Author(s):  
Grzegorz Struzikiewicz ◽  
Wojciech Zębala ◽  
Ksenia Rumian
Keyword(s):  
Taguchi Method ◽  
Cutting Force ◽  
Desirability Function ◽  
Optimal Solution ◽  
Regression Function ◽  
Function Optimization ◽  
Close Proximity ◽  
Optimal Setting ◽  
Steel Turning ◽  
Selection Of

The paper presents an analysis of the selection of the regression function in the optimization of steel turning using Taguchi method. The study attempts to investigate cutting force and temperature during turning of steel. Taguchi L16 (4) 2 orthogonal array has been applied for experimental design. S/N ratio and ANOVA analyses were performed to identify significant parameters influencing cutting force and temperature. Mathematical models for both response parameters i.e. cutting force and temperature roughness were obtained through regression analysis. The confirmation experiments carried out at optimal combination of parameters given by Taguchi’s analysis. The optimal solution provided by desirability function optimization was compared with the optimal setting of parameters given by Taguchi analysis. The optimization results provided by both techniques are in close proximity.

Multi-Objective Design and Selection of One Single Optimal Solution

2004 ◽  
Author(s):  
F. Levi ◽  
M. Gobbi ◽  
M. Farina ◽  
G. Mastinu
Keyword(s):  
Optimal Solution ◽  
Engineering Problem ◽  
Design Solution ◽  
Pareto Optimal ◽  
Large Set ◽  
Pareto Optimal Solutions ◽  
Optimal Solutions ◽  
Pareto Optimal Set ◽  
Final Design ◽  
Selection Of

In the paper, the problem of choosing a single final design solution among a large set of Pareto-optimal solutions is addressed. Two methods, the k-optimality approach and the more general k-ε-optimality method will be introduced. These two methods theoretically justify and mathematically define the designer’s tendency to choose solutions which are “in the middle” of the Pareto-optimal set. These two methods have been applied to the solution of a relatively simple engineering problem, i.e. the selection of the stiffness and damping of a passively suspended vehicle in order to get the best compromise between discomfort, road holding and working space. The final design solution, found by means of the k-ε-optimality approach seems consistent with the solution selected by skilled suspensions specialists. Finally the k-optimality method has proved to be very effective also when applied to complex engineering problems. The optimization of the tyre/suspension system of a sports car has been formulated as a design problem with 18 objective functions. A large set of Pareto-optimal solutions have been computed. Again, the k-optimality approach has proved to be a useful tool for the selection of a fully satisfactory final design solution.

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