bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Evaluation of Polymer Viscoelasticity During Flow in Porous Media: Elongational and Shear Analysis
Authors: Tahir M. , Hincapie R. E. , Be M. , Ganzer L. 
Published: March 2017

Abstract
This paper evaluates three viscoelastic phenomena in high molecular weight polymers (24-28 M Daltons) used for EOR applications based on core flooding experiments. First, we evaluate the impact of semi-harsh conditions (salinity, hardness, and temperature). Second, we investigate the impact of polymer degradation (pipe flow and sandface flow) on viscoelastic properties during polymer flooding. Finally, we propose a threefold approach for understanding these polymer viscoelastic properties by characterizing elongational, rotational, and oscillatory behavior.
For comparison, polymer solutions were prepared in a typical seawater brine (34 g/L and hardness: R+=0.13) and a typical German field reservoir brine (51 g/L and Hardness: R+=0.26). For experimental evaluation, core flooding experiments in conjunction with rheological, oscillatory, and elongational measurements were performed at room temperature (22°C) and a defined reservoir temperature (55°C). Effluents from core flooding experiments were analyzed to evaluate the changes in viscoelastic properties taking place at the sandface of the reservoir. Capillary tube (CT) injection was performed to simulate mechanical degradation occurring in flow lines. These approaches were used to study the influence of mechanical degradation on polymer viscoelasticity.
The polymer solution with deionized water displayed stronger viscoelastic properties, while the same polymer with both brines showed notable loss in viscoelastic properties, specifically at the higher temperature and with hard brine. Pressure drop analysis against interstitial velocity confirmed Newtonian, shear thinning, and thickening dominated flow, as already reported by researchers. Comparing core flood pressure drop data with eVROC pressure data allowed us to determine the turbulence-dominated excessive pressure drop in porous media. In addition, mechanical degradation caused by core flood experiments and CT injection revealed a reduction in elastic-dominated flow using various approaches. Finally, polymer solutions under reservoir harsh conditions (divalent ions, high temperature, and more TDS) resulted in a significant reduction in elastic behavior for all measurements.
Compared to previous studies which mainly focused on viscous properties, this study provides a microscale understanding of changes in polymer elastic properties while flowing through porous media depending on reservoir semi-harsh conditions. Confirmation of the existence of turbulence dominated excessive pressure drop in porous media will help understand pore-scale mechanisms in reservoir engineering.
Comprehensive Evaluation of the EOR Polymer Viscoelastic Phenomenon at Low Reynolds Number
Authors: Be M. , Hincapie R. E. , Rock A. , Gaol C. L. , Tahir M. , Ganzer L. 
Published: March 2017

Abstract
This study focuses on the investigation of the total pressure drop with regards to the shear, elongational and frictional forces experienced by the viscoelastic EOR polymers during the flow through porous media. The main analysis is performed to these forces occurring at low Reynolds numbers. Single-phase flooding experiments were conducted in Bentheimer core plugs and micromodels. Moreover, observations at pore-scale level are included by streamlines visualization analysis.
The overall approach can be summarized in the following sequence: 1) Single phase polymer flooding through Bentheimer core plugs 2) Analysis regarding the correlation between the pressure drop and the apparent flow behavior. This analysis also focuses on the contribution of shear, elongational and frictional forces to the pressure drop at low Reynolds number 3) Porescale streamline visualization experiments using micromodels 4) Analysis regarding the elastic instabilities or turbulences observed during the flow at low Reynolds number from streamline visualization experiments.
The preliminary evaluation from core flooding experiments shows a significant additional increase in pressure drop during the viscoelastic EOR polymers flow through porous media. The analysis regarding the cause of the additional increase in pressure drop indicates that shear and frictional forces are not the main determinants during the flooding process. This leads to a strong indication that the elongational forces experienced by the EOR polymers while flowing through the pores are the primary reason for the additional increase in pressure drop. A correlation between elongational forces and flow instabilities during the experiments was observed. It was also observed that at a given shear rate the onset of elasticity occurs. The onset of elasticity was evaluated by the observation of the normalized data obtained by taking the ratios between apparent and bulk viscosity.
Further evaluations from the porescale streamlines visualization experiments showed a clear occurrence of elastic instabilities during the flow at low Reynolds numbers in the form of vortices, crossing streamlines, and steadily changing flow directions of streamlines. These flow instabilities account for the additional increase in pressure drop.
This study provides a novel comprehensive evaluation approach to characterize the pressure drop observed during the EOR polymers flow through porous media with regards to their viscoelastic behavior. It should help to understand porescale polymer displacement and the contribution of viscoelastic properties on additional oil recovery. Furthermore, this paper provides evidence of the flow instabilities through visualization experiments and detailed analysis.
Significance of the Kinetics of Minerals in Reactive-Transport Problems
Authors: Khaledialidusti Rasoul , Kleppe Jon 
Published: March 2017

Abstract
The effect of geochemical reactions and the kinetics of minerals are not completely understood in reactive-transport problems such as low-salinity waterflooding (LSF) or alkaline/surfactant/polymer (ASP) injection method. These processes do not only act as an inert displacement and geochemistry also plays a major role in the fluid behavior and oil recovery. In this paper, first, the importance of the kinetics of minerals with fast and slow rate kinetic reactions (e.g., calcite and quartz, respectively) in different conditions during reactive-transport floods is investigated using PHREEQC geochemical package. Then, two-phase Buckley-Leverett (BL) flow is coupled with IPhreeqc which is open-source module of the PHREEQC geochemical package in order to study the effect of the geochemical reactions and the kinetics of minerals on the oil recovery in two different displacement distances. This coupling provides a simple tool for modeling the geochemical reactions to understand the effect of the geochemistry on the two-phase and 1D flow, and consequently the oil recovery. Finally, as an example, the significance of the kinetics of minerals in LSF and in oil recovery is studied at two different scales.
The results show that temperature, in-situ water composition and buffering capacity have a great impact on the kinetics of mineral. It has been shown that minerals with slow rate kinetic reaction (e.g., quartz) might be excluded in reactive-transport phenomena at core-scales. However, minerals with fast rate kinetic reactions (e.g., calcite) must be included when modeling lab results. On the other hand, the residence time at field-scales is large enough for the mineral dissolution and precipitation to affect the local equilibrium constants. Therefore, in modeling field-scale applications, local equilibrium assumption (LEA) can be applied for fast rate kinetic minerals, whereas kinetics should be used for slow rate kinetic minerals (e.g., quartz).
Evolution of pH and Retention of Different Alkali Species for ASP Flooding Field Applications
Authors: G. S. Kusumah , O. Vazquez 
Published: March 2017

Abstract
The era of easy oil recovery is over. One of the ways to economically improve oil production is through Enhanced Oil Recovery (EOR) implementation especially in mature field development. Alkaline-Surfactant-Polymer (ASP) flooding is considered to be the most promising EOR choice between the chemical flooding options due to its great effectiveness as result of synergy between Alkaline, Surfactant and Polymer. The main objective of this work is to analyse the pH evolution of different alkali species (NaOH, Na2CO3 and NH3) that should be used in ASP flooding application by using PHREEQC thermodynamic database software.
The work will divide the simulation into static and dynamic test. The static test will give result of pH evolution in terms of increasing alkali concentration in the brine to measure initial performance of each alkali species. The dynamic test will be used to simulate each alkali species performance in field application and involve of building a 1D reactive model that describe flow path of communication between injector and producer well in a reservoir and measures the pH evolution at the production well. This work will also use different reservoir brine and injection water composition for each test that will represent the onshore and offshore environment due to different amount of Total Dissolved Solids (TDS) of each case.
Through the result of this work it is found out that in onshore NaOH will be preferred based on its performance and cost, and as for the offshore environment case, NH3 will be more preferred based on its performance and storage size. One issue to be notice for the implementation of ASP flooding in offshore that it requires the injection water to be in low salinity and that the water treatment approach is more preferred compared to pipeline construction to provide the required injection water as it is more economical.
The Nature of Drilling Fluid Invasion, Clean-Up, and Retention During Reservoir Formation Drilling and Completion
Authors: Green Justin , Patey Ian , Wright Leigh , Carazza Luca , Saasen Arild 
Published: March 2017

Abstract
A reservoir-conditions coreflood study was undertaken to assist with design of drilling and completion fluids for a Norwegian field. Multiple fluids were tested, and the lowest permeability alterations did not correlate with the lowest drilling fluid filtrate loss volumes. This paper will examine the factors which contributed to alterations in the core samples.
A series of corefloods were carried out using core from 2 formations and different drilling fluids. Separate tests were carried out using drilling fluid alone and the full operational sequence. Filtrate loss and permeability measurements combined with interpretative analyses to understand what happened in the near-wellbore. Micro-CT "change maps" gave 3D visualisations of the thickness of operational fluid cakes and extent of retention/clean-up – valuable insights into factors that influence hydrocarbon recovery.
All drilling fluids tested had "normal" filtrate loss volumes, with one having notably higher losses with a particular formation. Normally this would be considered a bridging issue and "fixed", but those tests showed comparable or slightly lower alterations in permeability. Analysis showed that, despite deeper constituent infiltration, they were not contributing significant extra damage or retention; the nature of the drilling fluid attachment and cake seemed to be more relevant here than depth of invasion. Other examples will illustrate that the impact of drilling fluid infiltration and retention can range widely, and that there are more key factors than simply filtrate loss volume.
Results showed that focusing on the metric of filtrate loss alone may increase risk during drilling fluid selection. Understanding the relationship between filtrate loss, permeability/inflow alteration, retention/clean-up after production is important in selecting fluids as well as giving a better understanding of where improvements can be made. 3D visualisations of the alterations caused by drilling fluid allow conclusions to be drawn when previously there would be speculation.
Plug and Abandonment Campaigns from a Riserless Light Well Intervention Vessel Provide Cost Savings for Subsea Well Abandonments
Authors: Varne T. , Jorgensen E. , Gjertsen J. , Osugo L. , Friedberg R. , Bjerkvik O. , Halvorsen E. C. 
Published: March 2017

Abstract
Deployment of dedicated riserless well intervention (RLWI) vessels to perform a number of light-weight plug and abandonment (P&A) operations on subsea wells (also called pre-P&A) is now being used systematically in the North Sea as an alternative to modular offshore drilling units (MODUs). This paper describes the scope of work, project specific equipment and activities performed by RLWI vessels in preparation for the final abandonment by the MODU in two case studies, offshore Norway (Troll Osberg Gas Injection and Glitne fields). Based on the lower costs of RLWI compared to a MODU (Fjaertoft et al. 2011) and the shorter P&A operational times (Moeinikia et al. 2014), it is estimated that these case studies saved the Operator between 58.5 and 78 USD million.
Next Generation Annular Barrier Verification System
Authors: Dagestad Vibjørn , Bårdsen Johnny , Vasques Ricardo Reves 
Published: March 2017

Abstract
International standards for well barrier integrity traditionally prescribe cement as annular sealing material. Despite a more than 100-year long history using cementing techniques, a high number of wells have poor annular integrity and are facing sustained casing pressure (SCP). A quality assessment of the cement seal is obtained by return volume and surface pressure trend calculations together with bond logs. All of these measurements are indirect and open for interpretation. Commonly, excess cement volumes are pumped to account for uncertainties but cement failure rate remains high.
This paper describes an extensive testing and qualification program performed on a wireless downhole measurement system. Testing has been done on a component and system level basis on the permanently deployed equipment together with the hardware, software and telemetry on the equipment designed to retrieve the data. Focus has been given to robustness and simplicity to accurately capture the data of interest and ensure a fast and reliable download.
A direct measurement of annular integrity is now available. A continuous pressure and temperature measurement, named the Well Data Monitor (WDM), can be mounted on the exterior of the casing or liner. The system is non-intrusive to the tubulars and communicates by acoustics through the pipe-wall. No control lines to surface are needed. Interrogation of the sensor pack will provide a full history of events from deployment to the time of download. Hence, historical pressure and temperature data are available from the time of deployment, through the process of establishment of annular barriers to the final verification test. The verification test will provide a direct and non-negotiable measurement of integrity.
The development of the WDM was initiated following a need to provide verification for the Well Annular Barrier (WAB) to confirm to Norsok D-010 barrier requirements and to use the WAB as a barrier in open-hole.
Rathole Elimination BHA Success in Norwegian Seas
Authors: Hussain Sajjad , Huelvan Yvon , Labrousse Sebastien , Hassan Haitham Khalil , Esmat Mohamed , Dhaher Karam Sulaiman , Blackburn Jason 
Published: March 2017

Abstract
Rathole elimination (RHE) BHA comprised of hydraulics and ball-drop underreamer has been used in different North Sea fields. RHE success has been very important for operators in completion, cementing, casing running optimization, and handling contingencies by running intermediate liners and casings. One of the major benefits of the RHE system is time saving because the rathole is removed in the same drilling run and the dedicated underreaming run is not required. In today's field operations, this time saving has become considerably important on the older platforms as well. An RHE system has been successfully run on the North Sea continental shelf (NCS) with five different operators and in six challenging fields, resulting in significant time and cost saving for each operator. BHA and hydraulics design are the basis of these successful RHE operations. Starting from a vertical well to whipstock exits and 2D wells followed by 3D complex wells have established that the RHE system is fully directional and steering capability is not compromised by BHA complexity. Suites of applications, including the integrated dynamic design and analysis 4D platform was used for BHA optimization and stability, underreamer and bits cutting structure selection, and directional response prediction. Both push-the-bit and point-the-bit rotary steerable systems (RSS) have been used in these operations. RHE showed great success and technology maturity on NCS in various borehole sizes. This paper presents the historical run summaries and the technology maturity life cycle in the North Sea.
A Traction Tool for Liners and Sand Screens
Authors: Randeberg Erlend , Skadsem Hans Joakim , Gardner David , Stokka Sigmund , Kyllingstad Henrik , Larsen Torgeir 
Published: March 2017

Abstract
A traction tool has been built and tested as a part of the development of a long reach well concept. The application of the traction tool to assist the running of liners and sand screens in challenging wellbores is studied and the results and conclusions are described.
Full-scale testing of the traction unit prototype has demonstrated that it can deliver large axial forces to the string. A prototype tool for assisting during the completion phase of challenging wellbores is described, including the tool's measured performance from testing in casing.
The industry partners supporting the development work identified an opportunity to utilize the device to assist the completion operation to ensure that the target depth is reached.
Different scenarios where a traction device can provide a benefit include: Buckling of the running string in extended reach wellsInsufficient available string weight in shallow reservoirsAvoid rotating sand screens to reduce axial friction
The benefit of utilizing this tool is demonstrated by simulating the completion operation. Comparative well case studies are performed to study the completion operation, with and without the traction system included. A torque and drag model is used to estimate the mechanical forces present during the running of the completion string and these are compared to the buckling and load limits. Input parameters such as wellbore geometry, friction factors and completion string specifics are taken from relevant well examples. The operational performance for different positions of the tool in the running/completion string is also investigated.
Cement Degradation in CO2 - H2S Environment under High Pressure-High Temperature Conditions
Authors: Omosebi O. A. , Sharma M. , Ahmed R. M. , Shah S. N. , Saasen A. , Osisanya S. O. 
Published: March 2017

Abstract
Significant amount of oil and gas reserves contain CO2 and H2S. Leakage of these gases to fresh water aquifers and their escape to the surface compromises human health and safety and create unthinkable environmental hazards. Cement exposed to these acid gases degrade, thereby promoting their release through the wellbore to overlying fresh water formations and/or the environment. This study investigates how these contaminants aid the corrosion of well cement in high pressure-high temperature (HPHT) environment.
Experiments were conducted under two broad test conditions. In the first case, cement cores were aged at 100°F in CO2-H2S brine solution. The total test pressure was varied from 3000 psi to 9000 psi. In the second case, cement cores were exposed to brine saturated with gas mixture comprising H2S, CO2, and CH4 at total test pressure of 6000 psi. Temperature was varied from 100°F to 350°F. The compressive strength, shear bond strength, porosity, and permeability of the aged and unaged specimens were measured to quantify the alteration in these critical cement properties. Observations are supported with FTIR, SEM and EDS analyses.
As temperature increases, the presence of H2S shows more impact on the loss of mechanical strengths and increase in transport properties of Class G cement than Class H cement. Variation of H2S concentration also shows significant impact on cement integrity.
Compared to previous study involving the exposure of cement to pure CO2, the presence of H2S improves the relative strength of cement. However, transport properties are compromised. FTIR mineralogy confirms that the extent to which cement is carbonated by CO2 is limited by the presence of H2S. In addition, SEM and EDX indicate that ettringite was formed at low temperature (100°F). However, it dissolves at high temperature (350°F) without significantly compromising the structural integrity of cement.
The most significant new finding in this study is that the presence of H2S and its coexistence with CO2 under HPHT conditions minimizes the loss of the structural integrity of well cement by pure CO2. This is important because it narrows down the most significant factor to consider when designing acidresistant cements for HPHT wells.
Desenvolvimento territorial sustentável: uma nova experiência na Mata Atlântica
Authors: Tiepolo Liliani Marilia , Denardin Valdir Frigo 
Published: March 2017

Apresentamos as origens e os primeiros resultados de uma experiência de pós-graduação stricto sensu da expansão da Universidade Federal do Paraná (UFPR), localizada no litoral do estado. A partir de um projeto político pedagógico diferenciado e após oito anos de consolidação, foi criado o Mestrado Acadêmico em Desenvolvimento Territorial Sustentável. Seu desafio é realizar pesquisas científicas inter e multidisciplinares que contribuam para o desenvolvimento regional e para o entendimento das constantes tensões envoltas na conservação e degradação da natureza da região, um notável remanescente da Mata Atlântica brasileira. Questões paradoxais permeiam todo o território, pois além de rica biodiversidade, conserva traços culturais singulares, ao mesmo tempo em que se destaca como polo industrial de exportação de commodities do agronegócio e de prestação de serviços para a exploração do petróleo do pré-sal.
Formação docente na pós-graduação stricto sensu: experiências na Universidade Federal do Rio Grande do Norte
Authors: Magalhães Rita de Cássia Barbosa Paiva , Raffin Fernanda Nervo , Gutierre Liliane Dos Santos , De Azevedo Alcio Farias 
Published: March 2017

Este trabalho aborda a adesão ao Programa de Apoio a Planos de Reestruturação e Expansão das Universidades Federais (Reuni) no contexto da Universidade Federal do Rio Grande do Norte (UFRN) e tem por objetivo caracterizar ações voltadas à formação docente circunscritas à pós-graduação stricto sensu desta universidade. Discute experiências do Curso de Iniciação à Docência e dos Estágios em Docência, constituintes do Programa de Assistência à Docência na Graduação (PADG), como política institucionalizada para cumprimento do objetivo de capacitar docentes para o ensino de graduação e de pós-graduação, além de se reportar às experiências de articulação entre Graduação e Pós-Graduação nesta instituição de ensino. Por fim, acena para os desafios no tocante à dimensão de formação para a docência universitária na pós-graduação.