bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hyperferritinemia without iron overload in patients with bilateral cataracts: a case series
Authors: Kröger Arne , Bachli Esther B , Mumford Andrew , Gubler Christoph 
Published: September 2011

Abstract

Introduction
Hepatologists and internists often encounter patients with unexplained high serum ferritin concentration. After exclusion of hereditary hemochromatosis and hemosiderosis, rare disorders like hereditary hyperferritinemia cataract syndrome should be considered in the differential diagnosis. This autosomal dominant syndrome, that typically presents with juvenile bilateral cataracts, was first described in 1995 and has an increasing number of recognized molecular defects within a regulatory region of the L-ferritin gene (FTL).

Case presentation
Two patients (32 and 49-year-old Caucasian men) from our ambulatory clinic were suspected as having this syndrome and a genetic analysis was performed. In both patients, sequencing of the FTL 5' region showed previously described mutations within the iron responsive element (FTL c.33 C > A and FTL c.32G > C).

Conclusion
Hereditary hyperferritinemia cataract syndrome should be considered in all patients with unexplained hyperferritinemia without signs of iron overload, particularly those with juvenile bilateral cataracts. Liver biopsy and phlebotomy should be avoided in this disorder.
Molecular study of the perforin gene in familial hematological malignancies
Authors: El Abed Rim , Bourdon Violaine , Voskoboinik Ilia , Omri Halima , Youssef Yosra Ben , Laatiri Mohamed Adnene , Huiart Laetitia , Eisinger François , Rabayrol Laetitia , Frenay Marc , Gesta Paul , Demange Liliane , Dreyfus Hélène , Bonadona Valérie , Dugast Catherine , Zattara Hélène , Faivre Laurence , Zaier Monia , Jemni Saloua Yacoub , Noguchi Testsuro , Sobol Hagay , Soua Zohra 
Published: September 2011

AbstractPerforin gene (PRF1) mutations have been identified in some patients diagnosed with the familial form of hemophagocytic lymphohistiocytosis (HLH) and in patients with lymphoma. The aim of the present study was to determine whether patients with a familial aggregation of hematological malignancies harbor germline perforin gene mutations. For this purpose, 81 unrelated families from Tunisia and France with aggregated hematological malignancies were investigated. The variants detected in thePRF1coding region amounted to 3.7% (3/81). Two of the three variants identified were previously described: the p.Ala91Val pathogenic mutation and the p.Asn252Ser polymorphism. A new p.Ala 211Val missense substitution was identified in two related Tunisian patients. In order to assess the pathogenicity of this new variation, bioinformatic tools were used to predict its effects on the perforin protein structure and at the mRNA level. The segregation of the mutant allele was studied in the family of interest and a control population was screened. The fact that this variant was not found to occur in 200 control chromosomes suggests that it may be pathogenic. However, overexpression of mutatedPRF1in rat basophilic leukemia cells did not affect the lytic function of perforin differently from the wild type protein.
Exome sequencing identifies a missense mutation in Isl1associated with low penetrance otitis media in dearisch mice
Authors: Hilton Jennifer M , Lewis Morag A , Grati M'hamed , Ingham Neil , Pearson Selina , Laskowski Roman A , Adams David J , Steel Karen P 
Published: September 2011

Abstract
Background
Inflammation of the middle ear (otitis media) is very common and can lead to serious complications if not resolved. Genetic studies suggest an inherited component, but few of the genes that contribute to this condition are known. Mouse mutants have contributed significantly to the identification of genes predisposing to otitis media

Results
The dearisch mouse mutant is an ENU-induced mutant detected by its impaired Preyer reflex (ear flick in response to sound). Auditory brainstem responses revealed raised thresholds from as early as three weeks old. Pedigree analysis suggested a dominant but partially penetrant mode of inheritance. The middle ear of dearisch mutants shows a thickened mucosa and cellular effusion suggesting chronic otitis media with effusion with superimposed acute infection. The inner ear, including the sensory hair cells, appears normal. Due to the low penetrance of the phenotype, normal backcross mapping of the mutation was not possible. Exome sequencing was therefore employed to identify a non-conservative tyrosine to cysteine (Y71C) missense mutation in the Islet1 gene, Isl1
Drsh
. Isl1 is expressed in the normal middle ear mucosa. The findings suggest the Isl1
Drsh
mutation is likely to predispose carriers to otitis media.

Conclusions
Dearisch, Isl1
Drsh
, represents the first point mutation in the mouse Isl1 gene and suggests a previously unrecognized role for this gene. It is also the first recorded exome sequencing of the C3HeB/FeJ background relevant to many ENU-induced mutants. Most importantly, the power of exome resequencing to identify ENU-induced mutations without a mapped gene locus is illustrated.
Monte Carlo Algorithms for Default Timing Problems
Authors: Giesecke Kay , Kim Baeho , Zhu Shilin 
Published: September 2011

Dynamic, intensity-based point process models are widely used to measure and price the correlated default risk in portfolios of credit-sensitive assets such as loans and corporate bonds. Monte Carlo simulation is an important tool for performing computations in these models. This paper develops, analyzes, and evaluates two simulation algorithms for intensity-based point process models. The algorithms extend the conventional thinning scheme to the case where the event intensity is unbounded, a feature common to many standard model formulations. Numerical results illustrate the performance of the algorithms for a familiar top-down model and a novel bottom-up model of correlated default risk. This paper was accepted by Assaf Zeevi, stochastic models and simulation.
Optimal Compensation and Pay-Performance Sensitivity in a Continuous-Time Principal-Agent Model
Authors: Ju Nengjiu , Wan Xuhu 
Published: September 2011

This paper studies the optimal contract between risk-neutral shareholders and a constant relative risk-aversion manager in a continuous-time model. Several interesting results are obtained. First, the optimal compensation is increasing but concave in output value if the manager is more risk averse than a log-utility manager. Second, when the manager has a log utility, a linear contract is optimal when there is no explicit lower bound on the compensation, and an option contract is optimal when there is an explicit lower bound. Third, optimal effort is stochastic (state dependent). Fourth, consistent with empirical findings and contrary to standard agency theory predictions, the relationship between pay-performance sensitivity and firm performance and that between pay-performance sensitivity and firm risk can be nonmonotonic. This paper was accepted by Wei Xiong, finance.
Oklahoma Woodford Shale: Completion Trends and Production Outcome from Three Basins
Authors: Grieser Bill 
Published: September 2011

Abstract
The Oklahoma Woodford shale has been tested as a potential hydrocarbon producer since as early as 1955. Activity in this Devonian age shale experienced a major increase starting in 2004. Four distinct Woodford shale basins are presently being developed. This paper summarizes 5,000 completion stages performed in Arkoma, Ardmore, and Anadarko Woodford shale. Composite production averages are associated with each completion strategy, and a best-practice completion design is distilled from the available data.
There are four major Woodford basins in Oklahoma.
Anadarko Arkoma South Oklahoma Folded Belt (Ardmore) Chautauqua Platform (Wagoner County)
These four basins currently include more than 1,900 wells, of which only about one-forth are vertical and the majority are horizontal completions. Very recently, we have witnessed the total Woodford monthly production of gas rising from only ~0.4 Bcf in January of 2004 to more than 27 Bcf during the month of January 2010. Most early wells were oil producers and more commonly gas has been the target of recent drillling. Even so, the average monthly oil production has grown from ~1,500 bbl in 2004 compared to ~140,000 bbl per month currently.
To date, nearly all Woodford completions have used cemented lateral sections, with only a few known exceptions, while 5.5-in., 23-lb P-110 has been the most common pipe used.
Permian Basin Wolfberry: Stimulation Evolution and Economic Optimization
Authors: Metcalf Arthur S. , Coronado Juan A. 
Published: September 2011

Abstract
The "Wolfberry" play is named after the two main productive formations, the low-permeability Wolfcamp and Spraberry, and is a very large part of the everyday business in the Permian Basin. Activity in the Wolfberry has recently increased, spurred by the current relatively strong oil prices. However, the economic foundation of these producing wells is their stimulation and the management of completion costs.
All of these wells require multistage fracture treatments to achieve economic production and therefore significant effort has been given to continuous improvement in efficiently completing and fracturing Wolfberry wells. To illustrate the evolution of the optimization process, a retrospective of the changes implemented in fracturing Wolfberry wells over the past 10 years in several counties in the Permian Basin is presented.
This paper addresses in particular, choices involved in optimizing stimulation stages (including perforation schemes), treatment fluids and proppants, to maximize net present value contribution of the hydraulic fracturing treatments.
Selection of the Right Demulsifier for Chemical Enhanced Oil Recovery
Authors: Nguyen D. T. , Sadeghi N. 
Published: September 2011

Abstract
In this paper, the importance of five process variables (alkaline, surfactant, polymer, shear rate and oil cut) and their interactions that govern emulsion stability in chemical enhanced oil recovery (CEOR) was investigated. The surfactant, alkaline, and polymer decreased the size of oil droplets, increased the surface charge of oil droplets, and increased the film elasticity, making oil-water separation difficult. Selected cationic demulsifiers (patents pending) when added to a produced emulsion at ambient temperature for alkaline, surfactant, polymer (ASP) and surfactant, polymer (SP) processes yielded oil and water phases with greatly improved quality compared to emulsions treated with conventional nonionic demulsifier resins and polymeric cationic flocculants. Structure and performance relationships of alkyltrimethylammonium bromides and alkyldimethylbenzylammonium bromides (n=C8 to C18) were also studied. Octyltrimethylammonium bromide was the best demulsifier for SP flood and dodecyldimethylbenzylammonium bromide was the most effective for ASP flood. Di-alkyl quaternary ammonium bromides were more effective than mono-alkyl quaternary ammonium bromides of similar molecular weights. The zeta potential became less negative and the size of oil droplets remarkably increased when a cationic demulsifier was added to the emulsion. Application of this novel demulsifier resulted in the production of dry oil and clean water for a pilot field experiencing chemical breakthrough from an ASP flood
Controlled Release of Colloidal Particles and Remediation: Experimental Investigation and Modelling
Authors: Gravelle A. , Peysson Y. , Tabary R. , Egermann P. 
Published: September 2011

Abstract
Gas production from gas wells or storage reservoirs is sometimes associated with solid particles eroded from the rock matrix. This phenomenon often called sand production can cause damages to the equipments, leading to choke the wells under their full capacity. Colloid release is often associated as a precursor of larger solid production and clay release can be a forecast of inter-granular cement erosion.
Injections of dilute polymer/microgel solutions form a small part of the techniques employed today to deal with sand production in gas and oil wells. Nevertheless they could be used more often as a remedy against starting sand production problems as shown through recent field applications.
The paper presents laboratory experiments carried out with model systems to reproduce particle generation and their transport in porous media. The approach consists in following the evolution of the colloidal particle detachment after ionic strength reduction and in defining the key parameters for release rate prediction. A different behaviour is highlighted at short and long time and the model, built to predict the colloid production evolution, is based on the introduction of two different time scales of the eroded rate.
The laboratory experiments demonstrate the great efficiency of polymer/microgel treatments. The proportion of fines produced decreases drastically when the surface coverage related to the adsorption rate increases. The use of the model to describe the effect of the chemical treatment helps to show that this one does not modify the mode of production of fines but significantly reduces the quantity of fines likely to be carried away from the pore surface.
Thermal-Poro Elastic Stress Effect on Stress Reorientation in Production and Injection Wells
Authors: Zhai Z.. , Abou-Sayed A.. 
Published: September 2011

AbstractStress reorientation is an important issue for the cuttings injection batching, refracturing design and stimulation candidate well selection. Long term production/injection causes the principal stresses to reorient. Temperature differences and pore pressure differentials induce thermal elastic stress and poroelastic stresses. These induced stresses are the fundamental reasons for the reorientation of the stress field. A model and numerical scheme are developed to study the effects of thermal differentials and pressure differentialss on stress reorientation. The model couples thermal diffusion and convection with hydraulic diffusion to obtain the temperature distribution reflecting the cumulative impact. The effective poro-elastic and thermo-elastic stresses result from the 1-D displacement equilibrium equations in a radial system. The 3-D in-situ analytical effective stress is superimposed on the 1-D solution. Application of this methodology simplifies the modeling of the 3-D stresses in a deviated borehole. The method makes it practical to obtain the stress distribution at any given injection/production time. The thermal stress and poro-elastic stress effects on the stress reorientation are compared and evaluated. Field examples are presented to show that in some cases the thermal stresses play an important role on stress reorientation. The quantified results of the model will give guidance on fracture treatments and well plans during injector or producer construction.
Numerical Simulation and Multiple Realizations for Sensitivity Study of Shale Gas Reservoir
Authors: Kalantari-Dahaghi A. , Mohaghegh S. D 
Published: September 2011

Abstract
Shale gas in the United States went almost instantly from a practically invisible resource to massive reserves that challenge the largest conventional gas accumulations in the world. Shale gas success is directly the result of economically managed deployment of petroleum technology, namely horizontal wells .Horizontal drilling and multi-stage stimulation technologies are driving the successful development of shale plays.
Modeling and simulation of shale gas reservoirs poses a unique problem. The geological complexity of shale gas reservoirs—containing both natural and hydraulic fractures—makes accurate modeling a significant challenge. To overcome these challenges and maximize recovery of a shale gas field requires specialized methods and state-of-the-art technology.
In the first part of this paper an integrated workflow, which demonstrates a quantitative platform for shale gas production optimization through capturing the essential characteristics of shale gas reservoirs was discussed. A comprehensive sensitivity studies on key matrix, fracture system and all other shale related properties were performed and the results were presented. This study attempted to show how sensitivity analysis applied to this model can be used to aid in the design and history matching of a complex shale gas system.
In the second part of this paper the state-of-the-art technology using Artificial Intelligence and Data Mining (AI&DM) techniques which is called single well shale surrogate reservoir model (S3) has been built. Shale surrogate reservoir model is new solution for fast track, comprehensive reservoir analysis (solving both direct and inverse problems) using existing shale gas reservoir simulation models. This model was defined as a replica of the shale gas reservoir simulation model that ran and provided accurate results in real-time very fast and can be used for automatic history matching, real-time optimization, real-time decision-making and quantification of uncertainties. The intelligent model was verified using several completely blind simulation runs.
Method for Identification and Analysis of Polysaccharide-Based, Hydraulic-Fracture Flowback Fluid
Authors: Hoeman Kurt , Klasner Scott , Karcher Arron 
Published: September 2011

Abstract
To support the use of polysaccharide (PS)-based, hydraulic-fracturing fluids, a means of analyzing the decomposition products of PSs present in well flowback by ion chromatography (IC) has been developed. Polymer decomposition products obtained during fracture treatment flowback provide key information about fracture fluid recovery and reservoir properties. The methods developed provide an understanding of the hydrolysis of PSs in fracturing fluids as well as quantitative information regarding degradation products. The general structure of most PS biopolymers used in hydraulic fracturing is based on monosaccharides linked by acetal functionalities. Complete hydrolysis of these biopolymers results in monosaccharides. These monomers can be quantified by IC, while the presence of incompletely hydrolyzed oligomers can be verified by other means. The use of PSs as components of hydraulic-fracturing fluids is appealing because of their biocompatibility and biodegradability. Certain PSs, such as guar gums, in fracture fluids can result in the formation of insoluble residues when gel breakers are used. The breakers are necessary to reduce the fluid viscosity and permit rapid post- fracture reclamation of the fluid from the well. The formation of insoluble residues is driven by the hydrolysis of the side chains from guar’s mannose polymer backbone, which leads to components of reduced solubility. In certain other PSs, however, cleavage of substituents from the backbone is not believed to yield significant changes in solubility and thus avoids generation of insoluble residue and the loss of propped fracture conductivity.
Predicting Asphaltene Precipitation in Oilfields via the Technology of Compositional Reservoir Simulation
Authors: Fazelipour Waleed 
Published: September 2011

Abstract
Asphaltene precipitation is a sophisticated issue in the upstream oil industry, worldwide, and has detrimental effects on a variety of production processes in oilfields; it damages the properties of the reservoir and causes an unfavorable and significant decrease in oil production. It is very desirable for oil companies to investigate/predict the precipitation behavior of asphaltene in their subsurface reservoirs before it occurs. This allows them to optimize field development plans and review remedial solutions, in advance. To achieve this objective, complex compositional reservoir simulation technology was studied and utilized which is capable of simulating/predicting the dynamic aspects of this unwanted phenomenon.
Compositional reservoir simulation technology along with advanced phase behavior and fluid characterization, offer reservoir engineers, the best means to study the issue of asphaltene precipitation, throughout the life of reservoirs. Multiphase flash calculation procedures empower users to predict the onset point and help monitor the amount of precipitation in reservoirs as a function of time, pressure, and composition of the reservoir fluid under investigation. The detrimental effects of the issue on important reservoir properties such as reduction of porosity and permeability; and alteration of wettability can be predicted, as well.
A number of complex reservoir simulation cases representing various oilfield-production scenarios were carried out to study the issue of asphaltene precipitation. Results indicate that asphaltene precipitation severely damages the productivity of wells and reduces oil production. A key conclusion of achievements is the capability to predict the detrimental effects of asphaltene precipitation in oilfields without the need for data generation from expensive downhole samples.
This research presents a leading-edge technology that can be utilized by oil companies to help with the design of more accurate and reliable primary/secondary/tertiary processes (i.e. EOR) such that asphaltene precipitation in subsurface reservoirs could be predicted and avoided beforehand, in order to help resolve the challenges the E&P industry is facing in this area.
Coiled Tubing Operations from a Work Boat
Authors: Long N. , Raj R. , Srisa-ard S. , Son N. H. 
Published: September 2011

Abstract
Unless there is support provided by a workover rig or temporary fixed platform, coiled tubing (CT) intervention workover on a small offshore platform is not feasible. Usually, small offshore platforms have low deck load capacity and available deck space is insufficient for CT workover operations. To puzzle out the solution to this issue, CT operations from a vessel were discussed and subsequently developed more than a decade ago. In 2002, the technique was substantially refined and improved to improve safety and reliability, which allows well intervention from the deck of a floating anchored vessel. This technique utilizes a system which provides emergency CT disconnect and effectively compensates wave motion.
The system includes the CT slack-disconnect assembly, reel control cabin, CT stabbing system, platform support gooseneck and a Pan/Tilt/Zoom Closed Circuit video system. The combination of the mentioned equipment allows CT intervention applications to be carried out with minimum equipment on the platform in a safe and secure manner. The system is not only the solution for CT intervention on small offshore platforms but it also saves the rig up/rig down time, therefore minimizing human exposure to equipment handling. The system features improve the overall operation safety and provide an opportunity to perform CT stimulation with large treatment fluid volumes. Fundamentally, this system now forms a key part within an integrated service solution which allows CT services, pumping services, e-line, slick-line and testing services to be performed in a single smooth operation.
In Brunei, this technique has now been taken to a new level. The preferred vessel is now a relatively small self-propelled work boat, similar to those used for rig supply, albeit one fitted with a suitable pedestal crane, capable of lifting an injector head and support frame. These work boats allow swift movement between platforms and reduced reliance on support vessels such as tugs, anchor handlers or supply boats.
This paper introduces the features and benefits of a CT system which is designed to work from the deck of an anchored work boat and briefly summarizes the success of CT intervention campaigns in Brunei since 2007.