bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Placement Case Study for a Well in the North Sea Field
Authors: Kaur Amarpreet , Stalker Robert , Graham Gordon 
Published: March 2019

Abstract
This paper considers the placement challenge in selected wells in a North Sea Field and presents the importance of understanding reservoir properties such as relative permeability, mobility and fluid in place when attempting to simulate treatments in complex wells such as these. The work presents the challenges and solutions offered to minimise the scale risk in this mature field as a result of changes in the overall drainage strategy.
Many wells in the North Sea Field are complex and produce from multiple heterogeneous formations which makes them difficult to treat, and so effective placement is vital to mitigate downhole scaling. The wells highlighted in this paper were originally planned for minimal interventions. However as the field development plan matured an increased (albeit mild) sulphate scaling risk became evident in several production wells. Therefore, pre-emptive squeeze treatments were planned to mitigate downhole barium sulphate scaling. Given the heterogeneity in the formation this resulted in potential risks in the event that squeeze treatments could not be designed to give effective placement.
This paper presents the placement challenge that is seen in these wells in addition to potential methods of overcoming these challenges. Effective placement does not necessarily mean placement into all producing layers, but means placement of inhibitor into layers upstream of any potential mixing point of scaling brines. Therefore, this work highlights the necessary placement required for effective inhibition and the corresponding treatment designs that may achieve this. One treatment injection strategy to assist effective placement is the use of a staged diversion treatment which is simulated using a near-wellbore placement model.
This paper documents a case study of modelling placement, and the corresponding squeeze return, in a mature North Sea Field. It highlights the important influence of reservoir properties such as relative permeability effects (in addition to permeability, porosity, fluid mobility etc.) and how these are used such that chemical treatments in complex heterogeneous wells can be readily simulated without the necessity of using complex full field reservoir simulators.
Enhancing Scale Inhibitor Squeeze Retention in HT/HP & High Water Rate Wells - Laboratory to Field Case Study
Authors: Sutherland Louise , Jordan Myles 
Published: March 2019

Abstract
The practice of squeeze treatments to oil/gas production wells to prevent inorganic scale formation has been applied for over 30 years and during that period different mechanisms to retain the inhibitor chemical have been evaluated. The simple mechanism of inhibitor retention, adsorption/desorption has been complemented over the years by enhanced adsorption via mutual solvent and full precipitation of the active inhibitor onto the mineral surface of the reservoir.
Previously published studies have shown that the retention of phosphonate scale inhibitors in sandstone reservoirs can be enhanced through the addition of a ‘squeeze life enhancer’. This chemical, typically, a highly charged, low molecular weight polymer can be applied in either the preflush or overflush stage of the scale squeeze treatment. To date these studies have been conducted using low temperature (85°C) sandpack testing.
This paper details the laboratory work carried out under high temperature (146°C) field conditions to qualify the use of the squeeze life enhancer for field application.
The results of the formation damage/inhibitor return corefloods using an MEA phosphonate (EABMPA, Ethanolaminebis(Methylene Phosphonic Acid)) and polymeric squeeze life enhancer additive are presented. The coreflood results indicated that the addition of the additive within the overflush stage of the squeeze program resulted in a 19% extension of the inhibitor lifetime. The ability to extend the squeeze treatment was translated into reduced injected squeeze fluid treatment volume as injected fluid volumes was an issue for the wells being treated and therefore reduced associated oil deferment costs.
The paper will also present field data obtained from the initial two field trial treatments which were carried out in a North Sea field. The trial well had been treated more than ten times previously with the same MEA phosphonate as applied in the enhancer trial making direct comparison of the treatment performance possible. The treatment program applied to the wells resulted in no change to the clean-up rates of the treated well and no process upset during well reflow. The initial scale inhibitor returns from the field trial treatments showed the expected improvement suggested from the coreflood study.
The study brings value to the industry by providing the process to follow for qualifying and trialling a new technology in a challenging high temperature scaling environment with the results from the field supporting the carefully designed chemical selection and evaluation program.
Permanent Removal of Condensate Banking in Tight Gas Reservoirs Using Thermochemicals
Authors: Hassan Amjed , Mahmoud Mohamed , Al-Majed Abdulaziz , Al-Nakhli Ayman , BaTaweel Mohammed , Elktatany Salaheldin 
Published: March 2019

Abstract
Condensate banking is a common problem in tight gas reservoirs because it diminishes the gas relative permeability and reduces the gas production rate significantly. CO2 injection is a common and very effective solution for condensate removal in tight gas reservoirs. The problem with CO2 injection is that it is a temporary solution and has to be repeated frequently in the field in addition to the supply limitations of CO2 in some areas. Also, the infrastructure required at the surface to handle CO2 injection makes it expensive to apply CO2 injection for condensate removal.
In this paper, a new permanent technique is introduced to remove the condensate by using a thermochemical technique. Two chemicals will be used to generate in-situ CO2, nitrogen, steam, heat, and pressure. The reaction of the two chemicals downhole can be triggered either by the reservoir temperature, or a chemical activator. Two chemicals will start reacting and produce all the mentioned reaction products after 24 hrs. of mixing and injection. Also, the reaction can be triggered by a chemical activator and this will shorten the time of reaction. Coreflooding experiments were carried out using actual condensate samples from one of the gas fields. Tight sandstone cores of 0.9 mD permeability were used.
The results of this study showed that, the thermochemical reaction products removed the condensate and reduced its viscosity due to the high temperature and the generated gases. The novelty in this paper is the creation of micro-fractures in the tight rock sample due to the in-situ generation of heat and pressure from the thermochemical reaction. These micro-fractures reduced the capillary forces that hold the condensate and enhanced its relative permeability. The creation of micro-fractures and in turn the reduction of the capillary forces can be considered as permanent condensate removal.
Investigation into the Synergistic Interaction of a Range of Generic Scale Inhibitors for Improved Sulphate Scale Control in North Sea Topside Processes
Authors: Jordan Myles , Temple Erin , Sham Anita , Williams Helen , McCallum Catriona 
Published: March 2019

Abstract
Inorganic scale control of sulphate and carbonate scales with polymer, phosphonate and phosphate ester scale inhibitors is well established within the oilfield service industry. The environments in which these chemical work best have been published such as vinyl sulphonates are known to be very effective for sulphate scale control in low temperatures whereas phosphonates are much less effective under these same conditions but improve at higher temperatures. What is less well understood is the potential for synergistic interaction with blends of polymers/phosphonates/phosphate esters to give reduced treatment rates, lower chemical discharge volumes and potentially lower treatment cost.
In this paper evaluation of two North Sea produced waters will be outlined. Both produced brines have a high barium sulphate scale tendency but differ in the temperature at which the fluids arrive and depart the topside process one case with a temperature of 20C and the other at 90C. Static bottle test data will be presented to evaluate the crystal growth performance of single scale inhibitors and the improvements observed when blends of these same inhibitors are applied. Select dynamic tube blocking tests data to evaluate nucleation inhibition will also be presented so that mechanism of inhibition for the blended chemicals can clearly be highlighted.
The generic inhibitor evaluated included vinyl sulphonates co polymer, phosphate esters, poly aspartic acid. In the lower temperature environment, it was observed that a vinyl sulphonate/phosphate ester blend was more effective than either of the components by themselves. Poly aspartic acid blende with phosphate ester also give a synergistic interaction but the performance of this chemical required higher treatment rates than the vinyl sulphonate co polymer blend. At higher temperature the overall treatment rates were reduced as the sulphate scale saturation values were reduced and the synergistic effects of the polymers and phosphate ester blends were evident.
As well as classic static bottle tests performance tests were carried out in the presence of reservoir solids with stirring to further understand if the interaction of the generic chemicals within the blends with suspended solids would reduce the observed performance in the solids free test solutions.
The current regulatory challenges with REACH mean that the methods outlined in this study offer the potential to reduce chemical treatment rate, cost and environmental impact by evaluating the synergistic interaction of the current range of commercially available scale inhibitors so cutting out the very high registration costs/ time delays to the market associated with new molecule development.
Tuning Ionic Liquids for Simultaneous Dilution and Demulsification of Water-in-Bitumen Emulsions at Ambient Temperature
Authors: Abdelfatah Elsayed , Chen Yining , Berton Paula , Rogers Robin D , Bryant Steven 
Published: March 2019

Abstract
Thermal and flotation processes are widely used to produce bitumen from oil sand in Alberta. However, bitumen contains many surface-active components that tend to form water-in-oil emulsion stabilized by fines and/or asphaltenes. Although several demulsifiers have been proposed in the literature to treat such emulsions, these chemicals are sometimes not effective. We propose ionic liquids whose composition has been designed to enable effective treatment of these emulsions.
Different ionic liquids were synthesized and tested for their efficiency in treating bitumen emulsion obtained from a field in Alberta. Ionic liquids tested are mixtures of organic bases with acids. Mixtures of ionic liquids and bitumen emulsion were prepared at several mass ratios. The two components were mixed under ambient conditions. After mixing, segregation of different components in the mixture was accelerated by centrifugation for rapid assessment of the degree of emulsion breaking. Optical microscopy, rheology, thermal gravimetric analysis, and viscosity measurements were used to assess the effect of ionic liquids on bitumen emulsions.
The first set of ionic liquids with cations of different alkyl chain lengths were able to separate the water from the emulsion. However, these ionic liquids tend to form a gel when mixed with water. The number and length of alkyl chains proved critical for avoiding gel formation. Ionic liquids with multiple long chains on the cation were immiscible with the separated water. These ionic liquids were very efficient in diluting and demulsifying bitumen emulsion. The emulsion droplet sizes increased upon addition of the ionic liquid. The ionic liquid mixes into the bitumen phase released from the emulsion, yielding a viscosity at ambient temperature close to the pipeline specifications.
This work demonstrates that ionic liquids can be tailored to break bitumen emulsions effectively without heat input. The process developed in this paper can replace current practice for the demulsification and dilution of bitumen emulsions, which requires the emulsion to be heated significantly. Hence the ionic liquid process reduces the heat requirements and hence greenhouse gas emissions.
Kinetics and Thermodynamics of Iron Sulfide, Precipitation, Deposition and Control
Authors: Wang Xin , Ko Saebom , Liu Ya , Lu AlexYi-Tsung , Zhao Yue , Harouaka Khadouja , Deng Guannan , Paudyal Samridhdi , Dai Chong , Kan Amy T. , Tomson Mason B. 
Published: March 2019

Abstract
Iron sulfide scaling is a severe problem in flow assurance and asset integrity in oil and gas and deep-water production. FeS scale control is challenging due to the extremely low solubility, fast precipitation kinetics and complexity of ferrous iron and sulfide chemistry. Despite the ubiquity of FeS, we have limited understanding about the kinetics and thermodynamics of iron sulfide. To address this problem, we have developed a reliable anoxic plug flow reactor using argon gas to remove oxygen and PIPEs or MES buffer to control pH. The FeS (mackinawite) solubility, precipitation kinetics and phase transformation were the focus of this study. The impact of temperature (25 – 90°C), pH (5.92 – 6.91), ionic strength (0.15 – 4.30 M), Fe(II) to S(-II) ratio, dispersant and chelating reagent have been investigated. It was found that mackinawite is always the first FeS precipitated and could be stable for a week. It was suggested that low pH, high temperature and low ionic strength could accelerate the FeS phase transformation. FeS precipitation is under diffusion control at pH lower than 6.1, which could be accelerated by high temperature and high ionic strength. But the precipitation kinetics would be faster at higher pH. Some evidence suggests the importance of neutral FeS(aq) species at pH 6 −7. A polymeric compound containing amide functional group showed a promising effect by controlling the FeS particle size and reducing FeS scale retention rate. EDTA showed satisfactory FeS scale inhibition effect, as well as reducing FeS scale retention and H2S corrosion rate.
Application of Advanced Fluorescence Detection Technology to Improve Scale Management in Both Conventional and Sub-Sea Fields
Authors: Heath Stephen , Toivonen Susanna , Vuori Vesa , Puupponen Salla 
Published: March 2019

Abstract
Scale inhibitor (SI) analysis is an extremely important part of scale management and, in recent years, much work has been done on the development of specialist scale inhibitor analysis techniques like Liquid Chromatography Mass Spectroscopy (LCMS) to push the boundaries of low level scale inhibitor detection. However, LCMS requires costly and complex instrumentation and there was therefore still a need for the development of other advanced techniques like fluorescence (F) and Time resolved Fluorescence (TRF) that can be used on site to provide near "on line" data.
Fluorescence techniques are particularly suited to tagged polymers and naturally fluorescent molecules like polyamines whereas the operation principle of TRF is based on interactions between lanthanide ions and various functional groups of polymer or phosphonate scale inhibitors.
Both techniques work individually or in combination and this provides a distinct advantage for multiple scale inhibitor analysis in produced brines that enable the design of packages of different products for specific field applications. In addition, TRF and fluorescence techniques offer the capability of on-site detection compared to the majority of scale inhibitor analysis techniques and other advanced methods like LC-MS.
The ability to detect both phosphonate and polymeric scale inhibitors at very low MIC (&lt;1ppm) has the potential for significantly extending scale squeeze lifetimes. This has now also allowed highly efficient, F tagged polymers, to be used in field situations where scale squeezing was either stopped or the lifetime was significantly compromised because of the lack of confidence in the residuals analysis.
Specific field and theoretical examples from both sub-sea and conventional wells will be presented where the application of both advanced fluorescence and TRF techniques has shown significant improvements in scale management.
This paper will compare and contrast the pros, cons and limitations of both fluorescence and TRF techniques for both phosphonate and polymeric scale inhibitors. In addition, it will highlight examples where scale management significantly improves through the application of Fluorescence and/or TRF scale inhibitor analysis techniques in complex production scenarios.
Peripapillary retinal artery in first diagnosed and untreated normal tension glaucoma
Authors: RONG XIN , Cai Yu , Li Mei , Fang Yuan , Tian Tian , Pan Yingzi 
Published: March 2019

Abstract
Backgroud

Glaucoma, an important cause of visual impairment in many countries, remains a common eye condition due to difficulties in its early diagnosis. We analyzed the characteristics of retinal arteries to add a valuable technology for helping the normal tension glaucoma (NTG) diagnosis.

Methods

This study included 51 patients with newly diagnosed NTG with hemifield defects and 60 age-matched controls. Peripapillary retinal arteriolar calibers (PRACs) photoed by non-mydriatic retinal camera were measured using ImageJ by two masked readers. We also performed spectral-domain optical coherence tomography to evaluate retinal nerve fiber layer thickness (RNFLT) and optic disc parameters. Their relations to retinal arteriolar calibers were investigated by univariate and multivariate linear regression. The area under the receiver operating characteristic curve (AUROC) was used to confirm the powers to detect NTG by PRACs.

Results

PRACs in four quadrants were significantly reduced in individuals with first diagnosed NTG (82 ± 15.1 μm, 80 ± 13.6 μm, 71 ± 11.6 μm, and 64 ±10.0 μm) compared with those in age-matched controls (101 ± 9.8 μm, 105 ± 8.7 μm, 90 ± 7.5 μm, and 82 ± 9.8 μm). Superotemporal and inferotemporal PRACs in the visual field-affected hemifield were narrower than those in the unaffected hemifield in NTG group (P≤0.004). Temporal PRACs in the RNFL unaffected hemifield were significantly narrower than in healthy eyes (P<0.001). Superotemporal PRAC showed a significant correlation with superior RNFLT (β=0.551, P<0.001), and a similar relationship was found between inferotemporal PRAC and inferior RNFLT (β=0.296, P=0.050). These associations were independent of IOP. The diagnostic capability of temporal PRACs was satisfactory (superotemporal PRAC; AUROC 0.983, cut-off value 84.7 μm, inferotemporal PRAC; AUROC 0.946, cut-off value 94.2 μm).

Conclusions

Superotemporal PRAC and inferotemporal PRAC are valid parameters for discriminating patients with NTG. And it is likely that narrowed peripapillary vessels preceded the RNFL damage detected by digital retinal camera.
Establishment of Novel Cells Stably Secreting Various Human IL-18 Recombinant Proteins
Authors: Kumagai Asuka , Shimizu Kenji , Kurata Riho , Cui Xiaofeng , Isagawa Takayuki , Harada Masamitsu , Nagai Jun , Yoshida Yasuhiro , Ozaki Kei-ichi , Takeda Norihiko , Semba Hiroaki , Yonezawa Tomo 
Published: March 2019

Background:The immunotherapies against cancer, autoinmmune diseases or infection are remarkable development. These days programmed cell death (PD)-1 antibody-induced immune checkpoint blockade or chimeric antigen receptor-T cells (CAR-T) have been shown to have eminent therapeutic effects on tumor development. We have focused on adoptive transfer with human gamma delta T cells for novel immunotherapies. Additionally, IL-18 is one of the cytokines that enhances cytokine secretion and cytotoxicity of human gamma delta T cells.Method:Thus, we established novel cell lines stably expressing and secreting various types of human recombinant IL-18 proteins to their culture supernatants using episomal vector. We also differentiated primary cultured human gamma delta T cells from peripheral blood mononuclear leukocytes to validate biological activity of the IL-18 proteins using measuring IFN-γ by ELISA.Results and Conclusion:Finally, we demonstrated that the supernatant could activate human gamma delta T cells using monitoring interferon gamma in culture medium.
La Junta de Representantes o Consejo de los Departamentos, 1841-1843
Authors: Moreno Valle Lucina 
Published: March 2019

<span>La autora analiza la creación y el funcionamiento de la Junta de Representantes o Consejo de los Departamentos que fue concebida con el objeto de contar con una representación nacional que legalizara la elección de Antonio López de Santa Anna como presidente provisional de la República Mexicana. Señala que el orden constitutivo de esta junta emanó de las </span><em>Bases de Tacubaya</em><span>, firmadas el 28 de septiembre de 1841 por Santa Anna y otros generales que desconocían el gobierno de Anastasio Bustamante.</span>
¿Quién se amparó en el seudónimo Un Cura de Michoacán?
Authors: Cortés Arreola Raúl 
Published: March 2019

<span>Raúl Arreola Cortés intenta encontrar a la persona o personas que, bajo el seudónimo de </span><em>Un cura de Michoacán</em><span>, cuestionaron en diversas ocasiones la representación de Melchor Ocampo en el Congreso de Michoacán, y provocaron una de las escisiones más notables entre Estado e Iglesia que se recuerde en esa zona del país.</span>
Ideas políticas y sociales de Salvador Alvarado
Authors: Valadés Diego 
Published: March 2019

<span>Diego Valadés da a conocer el ideario político y social de Salvador Alvarado, expresado en su obra </span><em>La reconstrucción de México</em><span>. Este último, tras ser enviado por Venustiano Carranza a Yucatán para desactivar la rebelión argumedista, propuso un socialismo de Estado que regulara las cuestiones económicas, financieras y educativas en la península yucateca.</span>
La manifestación de los obispos
Authors: Romero Galván José Rubén 
Published: March 2019

<span>José Rubén Romero G. presenta el documento intitulado </span><em>La manifestación de los obispos</em><span>, carta pastoral publicada en 1859 que, según el autor, refleja la posición y la reacción de la Iglesia católica frente a las Leyes de Reforma.</span>
La Primera Guerra Mundial y la prensa mexicana
Authors: Parra Yolanda 
Published: March 2019

<span>Yolanda de la Parra estudia el papel de la prensa mexicana durante la Primera Guerra Mundial y las tendencias políticas que adoptaron los periódicos de mayor circulación en el país. Señala que </span><em>El Universal </em><span>fue el diario defensor de Estados Unidos y </span><em>El Demócrata</em><span>, por el contrario, de la causa alemana. La autora explica que las líneas políticas adoptadas por la prensa se debieron, principalmente, a la actividad propagandística, el financiamiento y el espionaje, así como a presiones comerciales de estas potencias que buscaban dirigir la opinión pública a su favor.</span>