bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pengaruh Vaporasi Bahan Bakar Pertamax Terhadap Performa Sepeda Motor Dibandingkan dengan Pemanasan Biasa
Authors: Fajariansyah Andre , Fahruddin A'rasy , Bukhori Ahmad 
Published: March 2017

Vaporasi bahan bakar adalah sistem penguapan bahan bakar, yaitu bahan bakar diuapkan menjadi gas dengan bantuan panas dari exhaust manifold. Vaporasi dari gas bahan bakar pertamax ini sangat efektif digunakan untuk menghemat bahan bakar pada kendaraan bermotor. Prinsip kerja dari sistem ini adalah dengan memanfaatkan panas knalpot untuk memudahkan penguapan bahan bakar menggunakan pipa preheater yang ditempel di exhaust manifold. Bahan bakar yang telah panas kemudian masuk ke tabung vaporasi dan dihisap menuju intake manifold. Pada penelitian ini sistem vaporasi bahan bakar dibandingkan dengan sistem pemanas bahan bakar biasa. Hasil penelitian menunjukkan bahwa sistem vaporasi bahan bakar lebih baik dari mesin standar maupun sistem pemanasan bahan bakar biasa dari segi daya maupun efisiensi. Dan sistem pemanasan bahan bakar menghasilkan performa yang lebih baik dari mesin standar. Peningkatan daya dengan sistem vaporasi mencapai 13,2% sedangkan sistem penguapan biasa mencapai 8,8% dibandingkan mesin standar.
A Systematic Investigation of Factors Affecting the Formation of Zinc Sulfide (ZnS)
Authors: Graham A. J. , Singleton M. A. , Sorbie K. S. , Collins Ian R. 
Published: March 2017

Summary
Work was undertaken to systematically investigate the factors that affect the formation of zinc sulfide (ZnS) in an aqueous system. Experiments were performed at a series of temperatures from room temperature up to 90°C, at a range of initial pH values and in two brine systems. The effect of pH was examined further by changing the salt from Na2S·9H2O to NaSH·xH2O, therefore changing the initial sulfide source from S2– to HS–, as part of an ongoing method-development strategy.
The formation of ZnS was achieved by the equivolume mixing of two preheated bottles, which contained aqueous “H2S” and zinc ions, respectively. Having pH adjusted the zinc brine to values calculated by an in-house thermodynamic model, the brines were preheated to the required temperature and mixed. Aliquots were removed at 2, 4, and 24 hours to perform elemental analysis by inductively coupled plasma optical emission spectrometry (ICP-OES), and pH measurements were performed on all samples after they had returned to room temperature. In addition, particle-size analysis and environmental scanning electron microscopy (ESEM) examination of the resulting precipitate were also performed for a subset of the samples prepared.
The reaction between zinc ions and aqueous “H2S” was quantitative at all temperatures up to 90°C and in both brines. The final pH values of the supernatant were independent of the zinc brine pH, and instead were dependent on the molar ratio of zinc and sulfide ions. With a high pH, sulfide-dominated, and a low pH, zinc-dominated, plateau regions were seen with a sharp inflection between the two. As a consequence, reaching field-representative pH values was seen to be extremely difficult while retaining the ability to alter the relative concentrations of the reacting ions. Altering the sulfide source yielded the same trend, although with different absolute values. These observations have been rationalized with reference to the thermodynamic constants governing the reaction through scale-prediction modeling.
The work presented here provides a greater understanding of the factors governing the formation of ZnS scale and the considerations required for more industrially relevant formation and inhibition experiments in the future.
A Direct Overparameterize and Optimize Method for Stratigraphically Consistent Assisted History Matching of Object-Based Geomodels: Algorithm and Field Application
Authors: Alpak Faruk O. , Jennings James W. , Gelderblom Paul , Chen Chaohui , Gao Guohua , Du Kuifu 
Published: March 2017

Summary
Object-based static models are typically constructed for stratigraphically complex reservoirs. In this approach, the stratigraphic architecture is represented by use of distinct objects with specific geometric attributes and petrophysical characteristics. It is a major challenge to condition such models to production data while simultaneously maintaining the geologic realism and static conditioning.
A novel work flow is developed for the assisted history matching (AHM) of object-based geomodels where the uncertain object locations and attributes are directly modified without resorting to (post-geomodeling) reparameterization techniques. It contains an object-modeling algorithm for channels and levees that provides direct access to the preraster geomodeling parameters for individual object locations and attributes. These parameters are gradually modified subject to physical constraints to achieve a history match. A fully integrated protocol is used in this process that automatically couples the static modeling algorithm with the reservoir simulator. The resulting work flow is moderated by a massively parallel and highly efficient iterative data-integration algorithm. In the AHM work flow, static and dynamic conditioning operations are respectively driven by separate objective functions and are performed at the iteration level in a sequential fashion. The static-conditioning step may add and remove objects in the geomodel, which changes the number of active AHM parameters over the course of the iterative search. The work flow handles such operations with minimal impact on the robustness of the search.
A potential application of the direct AHM work flow for object-based geomodels is the identification of locations and attributes of channels in deepwater turbidite reservoirs, where the channels are typically below the resolution of the seismic data; the well spacing is typically larger than the characteristic object dimension, yet the production data exhibit strong sensitivity to channel connectivity. The concept of gradually adjusting the channel locations with the information in the production data (while maintaining static conditioning) is demonstrated on a real data set for a deepwater channelized-turbidite reservoir. The models proposed by the new AHM work flow not only improve the difficult-to-history-match injected-gas-breakthrough profiles but also provide geologically based explanations for them, taking into account the channel connectivity. The proposed AHM work flow ensures consistency across static and dynamic models by integrating multidisciplinary data with an easily auditable and replicable capability.
Method to Improve Human Resource Allocation in Project Teams Using Simulation: An Application to a Well Engineering Team
Authors: Lira G. A. , Pedrassa M.. , Veiga I. G. , Torres C. E. , Santos A. S. 
Published: March 2017

Abstract
Human Resources allocation is a crucial factor for success in multi-project companies. It should consider the quantity of professionals needed to develop the project and the amount of time these professionals can dedicate to it. Companies where the core business is engineering design, software design or research and development projects, usually need a variety of specialists and the allocation of these workers on the projects can be done by a simulation of the process aiming to obtain better system performance. This work makes an analysis of sizing and allocation of human resources on design processes, proposing a simulation based method to improve it. An application to onshore oil well design process for a petroleum company was made, generating a model that represents the amount of professionals needed according to a given demand. After that, some scenarios were simulated aiming to improve the system performance metrics. Through the proposed method, the process was analyzed, identifying some bottlenecks and improvement points related to downsizing and deadline accomplishment. The simulated scenarios have shown that an organization modification through centralization of well engineering offices could reach these goals.
Effect of Pressure Depletion on Stress Field and Casing Load Alteration in Mature Fields: A Case Study
Authors: Zhang Peng , Zhang Shang , Hu Ningjie , Zhang Feifei , Makhmoor Felor , Carlos Sandoval Juan 
Published: March 2017

Abstract
Long-term oil production can lead to pressure depletion in mature fields, which can cause noticeable wellbore impairments, particularly in soft formations. This paper presents a case study that was conducted with the application of mature field data from Latin America to identify stress field and casing load alteration caused by long-term production.
A stochastic reservoir model was built integrating field geological, geophysical, and petrophysical analyses. The model displayed facies-controlled petrophysical properties distribution. A simulation model was then developed to provide reservoir pressure profiles. The overburden displacements induced by pressure depletion were calculated using Geertsma’s analytical method based on the poroelasticity theory. Then, the strain and stress fields in the formation were determined following a finite difference scheme. Following, casing integrity and wellbore stability analyses were performed.
Reservoir simulation results show an average pressure drop of approximately 800 psi from initial field pressure. Pressure profiles were used to calculate displacements and stresses in overburden rocks, and displacements were incorporated in casing design software. Results show increased compressional stress along the casing string, which can lead to casing and cement failure. Moreover, the induced stresses caused by pressure drop alter the in-situ stress fields in the formation. The result is stress-cloud movement along the wellbore toward the failure envelope. Corresponding precaution is necessary to help mitigate risks associated with long-term oil production in this field.
This paper provides a methodology for predicting production-induced wellbore integrity problems and suggestions for helping improve safety management and reducing environmental risks associated with mature field development.
Comparative Analysis of Two-Phase Flow in Porous Media in Two Different Configurations of Wells Through 3D Numerical Solution Using OpenFOAM
Authors: Soares Vivas Cláudio , Fernando Britto Antonio , da Cunha Lima Ivan C. , da Cunha Lima André T. , de Almeida Murilo P. 
Published: March 2017

Abstract
With the advance of high-performance computing (HPC) the use of CFD software has become common in research in Fluid Dynamics, either to obtain the numerical solutions of differential equations that model the various systems or the dynamics for viewing and analyzing data obtained in the simulations. In this work we look to benchmarking between two distinct two-phase flows from two geometrically different wells through the analysis of their respective accumulated volumes of non-wetting fluid in the outflow. Three simulations were performed, for each set of wells, both during the same interval of time and under the same pressure gradient. The OpenFOAM software and Finite Volume Method for solving differential equations were used.
Influence of Well Control Parameters in the Development of Petroleum Fields Under Uncertainties
Authors: Santos Daniel Rodrigues , Schiozer Denis José 
Published: March 2017

AbstractIn the development of oil fields, many parameters have to be selected in optimization procedures, demanding large computational effort, especially when uncertainties are considered. Therefore, it is common to separate design variables (G1) and well control variables (G2) optimization in a hierarchical process, but this may yield suboptimal results. We propose a well control analysis under uncertainties to verify whether G2 can be optimized separately in the development phase of petroleum fields. We also investigate the impact of G2 optimization on economic returns when platforms limit the production and for more pessimistic production costs. We perform reactive and proactive G2 optimization under uncertainties on a Benchmark Model (UNISIM-I-D, based on Namorado field) in three cases. In Case I, we use previously optimized strategies for G1, while G2 were controlled in a simplified way considering geological and economic uncertainties. In Case II we investigate the G2 optimization based on expected monetary value (EMV) for a restricted platform. Case III adopts the same restriction of Case II, but considers a pessimistic economic scenario. We consider five procedures for G2 optimization: (P1) longterm bottom-hole pressure control; (P2) short-term rates control; (P4) long-term rates control; (P4) well shut-in time control; and (P5) a combination of these procedures. In Case I, the EMV low percentage increase after G2 optimization indicates that a hierarchical process can be used in similar problems. Yet, G2 should be optimized during the lifetime of the field to increase EMV without additional cost. Depending on the representative model (RM) that best characterizes the field, there are potential further gains of almost 200 million USD for one of the scenarios studied. We achieved an increase of EMV around 8% for Case II. This suggests that G2 have a greater economic return when the platform restricts the production and injection for the field and G1 were not previously optimized. Case III showed even higher EMV gain (34%) indicating the importance of considering the economic scenario when defining the G2 strategy for the field. To reduce the search space in optimization problems, conventional techniques focus on optimizing design variables, underestimating the influence of well control management on G1. Moreover, some works do not include uncertainties and operational constraints. The results of this work indicate that G1 and G2 can be optimized hierarchically for a situation in which platforms do not constraint production or injection (Case I), since G2 variables have lower influence. This conclusion is not valid for restricted platforms and a pessimistic economic scenario (as in Case II and III) where G2 have higher influence in the results.
Practical Management in Mature Field Operations
Authors: Hirschfeldt Clemente Marcelo , Bertomeu Fernando Diego , Lobato-Barradas Gerardo 
Published: March 2017

Abstract
An operation model for mature field not only should be used during a world oil price crisis, but also it should be incorporated as a best practice during the life of the oil field, consequently, in mature field projects it is always possible both to improve its profitability indicators and to increase its hydrocarbons production. One of the most important challenges is to incorporate these actions as a mature field management culture by supporting existing facilities operations and field elements using best practices focused on processes, human resource skills and technological elements.
Operators have a great opportunity concentrated in these key aspects to optimize results by reduction and optimization of costs and improvement of operations.
The objective of this paper is to provide a practical guide to be considered during the field operation and management of mature asset, addressing actions to maximize the operation efficiency, maximize the hydrocarbon recovery factor and to optimize costs and resources.
It describes an integrated operations process for low profitability projects/fields, like mature fields and marginal fields, summarizing best practices to identify opportunities in existing operations.
The paper also describes how to find opportunities by clear understanding the relationship among key processes such as:Reservoir Management and Surveillance,Water Management, Waterflooding and EOR,Drilling, Completion, and Production Engineering,Artificial Lift Management,Efficiency and Cost Control.Suppliers and service company's management
These best practices addressing organized processes, human resource skills and technology elements are described clearly and they are presented as tools for easy implementation. Case studies in Mexico and Argentina are shown, along with management models for implementing, surveilling and maintaining mature fields which resulted in lower operation costs and a sustained oil production increase.
An Alert-Based Monitoring System to Evaluate a Water Injection Pilot in the Shushufindi Field, Ecuador
Authors: Paredes Luis , Fonseca Claudio , Meza David , Torres Camilo , Henson Richard , Withney Patricio , Lafournere Jean Paul , Ponce Gustavo 
Published: March 2017

Abstract
Secondary recovery by water injection is one of the most popular methods to increase reservoir pressure and sweep efficiency in the industry. It is a cost effective technology in reservoirs such as Shushufindi field, where water, energy and sink points are easily available. This pilot aims to provide proof of concept of water injection in mature Ecuadorian fields.
The water injection pilot project was carried out in the central north area of the field, in the lower U reservoir, selected as the target injection horizon due to pressure depletion. The injection started in December 2014 in SHS-246D and SHS-244D and then in 2015 two more injector wells were set up, SHS-247 & SHS-003. These wells are located in a 125 acres area, based on inverted five spot pattern.
Secondary projects around the world have shown that the success of any water injection project is based on an exhaustive monitoring and surveillance process, along with using the many analysis tools and plots available.
Shushufindi, however, needed a specific tailored toolset that fits the surface operating conditions, one that is able to monitor the variables required to understand the local reservoir hydraulic behavior, minimizes issues in the injection cycle, and provides quality data for the continuous improvement of the water injection pilot. In order to achieve this objective, some variables were selected and recorded in a group of theoretical plots. This was achieved by developing a series of workflows on a production management software platform, centered on an alert system to rapidly identify changes in the monitored injection variables and to respond if needed.
This monitoring system allows a quick identification of well plugging issues in injector wells through the use of Hall plots, it also tracks the water quality at different points in the water processing plant allowing adjustments to made to the process to improve the water quality if needed, provides information for reservoir characterization monitoring, Voidage Replacement Ratio (VRR), and determines the water injection response in producer wells by monitoring the production parameters.
Enhancing Reservoir Understanding in Mature Fields: Adjoint-State Method Applied to a Semi-Synthetic Model
Authors: Awofodu D. D. , Ganzer L.. , Almuallim H.. 
Published: March 2017

Abstract
Model validation using available history data demands that the model reflects relevant behaviour occurring in the subsurface. Reservoir models lacking in proper modelling of essential reservoir behaviour are poor representatives of reality. Usually, calibrating these models to history data require excessive use of parameter fudging to achieve meaningful match results. To combat this issue, an efficient approach to improve reservoir understanding is presented that investigates hidden reservoir behaviour at field, region and well level.
The model screening approach uses static grid properties to explore unmatchable models for hidden reservoir behaviour. Permeability and/or porosity is defined as an input for the minimization problem with preset uncertainty limits ranging from zero to values greater than the default maximum values. The adjoint-state method is employed to condition simulation models to observation data. Unrealistic match results are realized at this stage which cannot be used for performance forecasting. Logical interpretation are generated for the extreme property updates. Feedback from interpretations are then used to enhance reservoir understanding. The PUNQ-S3 model is used to test proposed screening methodology.
A variant of the adjoint-state method executed in an unrestrained manner proved its capability to reveal hidden reservoir behaviour. A handful of patterns that draws attention to hidden reservoir behaviour were observed in permeability and/or porosity distribution. In the case of a hidden fault, the permeability distribution around influenced wells experiences a sharp contrasting change; the high permeability region seeks more oil while the low permeability region constrains oil production. Also, in the case of a hidden aquifer, we observed an extreme vertical porosity and permeability update travelling down through all layers into the oil-water contact zone. Hidden channels are represented as high permeability streaks connecting affected wells. So far, the model screening approach suffers from one limitation – an inability to differentiate between a reservoir boundary and a fault close to the boundary.
To guarantee that geological consistency is not sacrificed at the expense of history matching, local or global updates made to the starting model are restricted to true model variogram. The most crucial finding is that the production history must account for the physical mechanisms occurring in the representative reservoir. On the contrary, noisy production data or errors in field measurements limit the effectiveness of the adjoint-state method to provide insights on hidden reservoir behaviour.
Evaluation of Novel Products Applicable to Enhanced Oil Recovery
Authors: Legarto Maria Leticia , Vega Isabel , Robledo Dario , Bordenave Veronica 
Published: March 2017

Abstract
Chemical Enhanced Oil Recovery (EOR) technologies include polymer, alkaline, surfactant injection and any combination of those. One of the main chemical EOR process is surfactant flooding whose key mechanism is the interfacial tension (IFT) reduction between oil and the displacing fluid. The IFT reduction is associated to the increase of capillary number, which is the dimensionless ratio of viscous-to-local capillary forces. Therefore, as IFT is reduced through the addition of surfactants, the ultimate oil recovery is enhanced.
The purpose of this work is the design of a systematic methodology to evaluate already existing products as well as new ones that are typically used for wells cleaning or damage removal, to be applied for Chemical Enhanced Oil Recovery. Solutions at different concentrations were prepared in synthetic brine. The behavior of these solutions at room and reservoir temperatures was observed. Quick Scans (qualitative method) were performed to evaluate the decrease of the IFT with two crude oils from Argentina basin; and the IFT was measured with a Spinning Drop Tensiometer.
According to some previous consulted literature, enzymatic, terpenic and surfactant products should present an intermediate recovery between a polymer flooding and ASP / SP processes. To understand how this recovery works, flow tests using 80 microns glass beads were carried out. These results led to an approximated recovery factor applying flooding of these chemicals.
Efficacy of Bisulfite Ions as an Oxygen Scavenger in Monoethylene Glycol (At Least 20 wt%)/Water Mixtures
Authors: Salasi Mobin , Pojtanabuntoeng Thunyaluk , Wong Sindee , Lehmann Marc 
Published: March 2017

Summary
This study investigates the oxygen-scavenging behavior of bisulfite ions in monoethylene glycol (MEG)/water mixtures at concentrations commonly found in gas-transportation pipelines. Temperatures and pH values were varied. The influence of transition-metal (TM) ions to catalyze the bisulfite oxygen scavenging was studied. Experimental results indicate that MEG significantly inhibits bisulfite oxygen removal, which is hindered at low pH values and, to some extent, temperature. TMs can accelerate the oxygen-scavenging reaction in pH-unadjusted solutions, although the rate was still lower than that of the pH-adjusted solutions. The possible mechanism for such behavior and industrial implications are discussed.