bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coupled Geomechanics and Flow Simulation for an Embedded Discrete Fracture Model
Authors: Moinfar Ali , Sepehrnoori Kamy , Johns Russell T. , Varavei Abdoljalil 
Published: March 2013

Abstract
The effect of geomechanics on fluid flow is more crucial in fractured reservoirs due to presence of fissures, which might be more stress-sensitive than the rock matrix. The flow characteristics of fractures are significantly affected by effective normal stress exerting on them. In spite of extensive experimental and field studies that have demonstrated the dynamic behavior of fractures, fracture properties have been often treated as static parameters in the simulations of naturally fractured reservoirs. Realistic modeling of production in fractured systems requires including the dynamic behavior of fractures into a discrete fracture model.
We have incorporated the dynamic behavior of fractures into an embedded discrete fracture model, called EDFM. The coupled model allows inclusion of the impact of stress regime on fluid flow in a 3D discrete fracture network. We use empirical joint models to represent normal deformation of pre-existing natural fractures and couple them with the EDFM approach. Using these models, the aperture and permeability of an arbitrary-oriented fracture become functions of the effective normal stress acting on the fracture plane. In addition, we allow for fracture-conductivity tables to model dynamic behavior of propped hydraulic fractures in stimulated reservoirs.
We present several examples in this study to show the applicability and performance of the coupled geomechanics-EDFM approach for the simulation of naturally fractured reservoirs. We examine the effect of pressure-dependent fracture properties on production leading to the conclusion that fracture deformation, caused by effective stress changes, substantially affects hydrocarbon recovery. Our simulations show that the significance of such effects on production strongly depends on parameters controlling the deformation behavior of fractures. Simulations also show that creating sufficiently high-conductivity fractures during stimulation treatment of unconventional reservoirs can mitigate the adverse effect of hydraulic fracture closure on production to a good extent. Furthermore, the coupled geomechanics-EDFM approach does not degrade the computational performance of EDFM, which is a promising new approach for modeling discrete fractures in a robust and efficient manner.
Performing Reservoir Simulation with Neural Network Enhanced Data
Authors: Isaiah J , Schrader S. , Reichhardt D. , Link C. 
Published: March 2013

Abstract
The use of artificial neural networks (ANN) for reservoir analysis now makes it possible to predict important reservoir properties from combinations of data such as well logs, production data, seismic data, etc. In this work, an ANN was combined with a geostatistical linear estimation algorithm in a technique called the hybrid approach, which was used to enhance sparse data to include in a reservoir simulation model with the goal of reducing history matching time. The case study field, Fort Collins Field, is situated on the N-S anticline on the western edge of the Denver Basin in Colorado. The available porosity and permeability data needed to build a reservoir simulation model are old and sparse.
Available well logs and cores were used as inputs to the hybrid model. This model was then used to predict porosity and permeability for the reservoir and these values were then included in a reservoir simulation model. To evaluate the hybrid approach, the reservoir simulation model was history matched with the case study historical production data and compared to a model with average data. The result confirms that the hybrid approach history matched better and faster compared to the simple averaging-technique. The history match results from both methods were compared based on the percentage error. This unique approach will benefit older fields with sparse data.
Real-Time Streaming Data Management as a Platform for Large-Scale Mission Critical Sensor Network Applications.
Authors: Beggs Ronnie , Abadie Victor H. 
Published: March 2013

Abstract
Oil and gas operators must process, analyze, and react in real time to increasing volumes and rates of streaming data in order to improve safety, compliance, and profit. For example, real-time analysis of streaming data from drilling rig sensors, intelligent wells, and digital oilfield installations enables early detection of drilling hazards and pending equipment failures, thereby reducing rig time, intervention, and shut-ins.
Data problems include the need for real-time integration of operational systems and an inability to maintain accurate and current information across all systems and data warehouses. Poor integration leads to duplication of data and systems, and a lack of visibility across all monitored assets, resulting in the delayed identification of the root cause of problems.
This paper presents a streaming data architecture that is capable of processing and analyzing rig data and smart oilfield data in real time. Further, the architecture supports the continuous, streaming integration of any and all of an organization&apos;s sensor data, operational platforms, and data warehouses. The approach aggregates and analyzes live, streaming data on the fly, without the need to store the data first. Large volumes of high velocity streaming data in any format and from all sources can be processed continuously and delivered to existing operational systems and data warehouses.
The architecture increases efficiency by removing data silos and by ensuring that all systems and data warehouses are kept accurate and up to date in real time. This results in faster decisions that are better informed and based on consistent, accurate, and timely information.
Design of an Automated Drilling Prediction System – Strengthening While-Drilling Decision Making
Authors: Pérez Bardasz Samuel R. , Hernández Alejadre Edwin David , León Armando Almeida 
Published: March 2013

Abstract
Real-Time systems and monitoring centers continue gaining interest as decision-makers face tight time constraints to discover and develop hydrocarbon fields, while the increased complexity of wells being drilled is coupled with reduced engineering workforce capacity.
The promise of remote data visualization and analysis, problem mitigation and optimal utilization of highly-skilled team members is being realized. The predictive side, however, is still a challenge for the industry. Anticipating unplanned drilling events such as stuck pipe, lost circulation and kicks, represents a tremendous opportunity to return value from data, in the form of unplanned downtime reduction, cost saving and even a safer operating environment.
Data mining processes are fundamental to obtain the predictive benefits of real-time systems, and have been progressing from descriptive to predictive optimization methods. In design of these systems, descriptive and predictive methods are enhanced by real-time and historic data corresponding to six drilling operations aspects: bottom hole assembly design, mud properties, equivalent circulation density, lithology column description, rock conductivity and well-correlation events. Algorithms and human participation are taken into account to generate "accurate alerts" rather than simple out-of-range alarms. Specific examples are provided in order to show how available technology, data mining and model development can increase drilling efficiency by enabling better while-drilling decision-making.
Advanced sensor technologies, improved data quality control, Wellsite Information Transfer Standard Markup Language (WITSML) data advantages, and virtual real-time drilling optimization concepts have been assimilated in the design and implementation of the prediction system. This paper aims to be useful as a reference to expand and improve decisions while drilling the well, by anticipating and identifying trouble zones using real-time predictive analyses.
Optimal Sensor Placement for Multi-Phase Flow Rate Estimation Using Pressure and Temperature Measurements
Authors: Kawaguchi K. , Takekawa M. , Wada H. , Ohtani T. 
Published: March 2013

Abstract
This paper discusses on uncertainty and optimal sensor placement for estimating multi-phase flow rates from the producing well by inversely solving the well flow model, given the down-hole temperature and pressure measurements. Uncertainty of the estimated multi-phase flow rates are evaluated by solving the error propagation from the given uncertainties of pressure and temperature measurements used to make the estimation. The uncertainties of the multi-phase flow rate estimations are studied for different sensor combination and location to search for the optimal sensor placement which gives the lowest uncertainty for multi-phase flow rate estimations. From the simulation study, preferred sensor combination and location of pressure and temperature measurements are found for typical oil gas 2-phase vertical well case. The methodology can be applied for reliable down-hole multi-phase flow monitoring and optimal sensor placement design for monitoring the multi-phase flow rate using temperature and pressure measurements within an allowable estimation uncertainty and sensor cost.
Improving Performance of Alarm System by Implementing Effective Alarm Management Philosophy: A Case Study of West Kuwait Field
Authors: Al-Azmi Falah , Parikh Chirag A. 
Published: March 2013

Abstract
The DCS (distributed control system) alarm system of gathering center of West Kuwait field at Kuwait Oil Company was not functioning as required. DCS alarm system was generating around 400 to 700 alarms in one hour which was out of operator's alarm handling capacity. This was highlighted as one of the key contributing factor to the seriousness of process upsets & incidents. The overall alarm management system was thoroughly investigated to understand root cause of these poorly functioning system and to improve it accordingly. A detailed investigation revealed lack of alarm management philosophy during design stage and subsequent over configuration of DCS alarms as main cause of this poorly functioning system. All DCS alarms were analyzed in detail to eliminate all unwanted alarms to achieve manageable alarm level of around 5-20 alarms per hour.
This paper shares field experience for analysis of DCS alarm system and explains main root causes which resulted in such poorly functioning alarm system at gathering center of West Kuwait field. It also provides guidelines for improving such alarm system & for developing alarm management philosophy to implement efficient DCS alarm system. It also shares some of the actual alarm data and their analysis which supports need of well-developed alarm management philosophy for implementation of efficient DCS alarm system.
It was observed that total 182 alarms were mainly contributing for significantly higher rate of DCS alarms. These alarms were mainly categorized as frequent alarms, duplicate alarms and chattering alarms. Effective implementation of alarm management philosophy has significantly reduced these alarms and reduced alarm rate from around 700 per hour to 10 per hour.
The paper justifies need for Alarm management philosophy to ensure implementation of efficient DCS alarm system and also provides guideline to achieve it.
Significant Coronary Stenosis in Asymptomatic Chinese With Different Glycemic Status
Authors: Xu Yu , Bi Yufang , Li Mian , Wang Tiange , Sun Kun , Xu Min , Lu Jieli , Yu Yi , Li Xiaoying , Lai Shenghan , Wang Weiqing , Ning Guang 
Published: March 2013

OBJECTIVE
To evaluate coronary artery stenosis in early diabetes or prediabetes asymptomatic of myocardial ischemia in community-dwelling Chinese adults.

RESEARCH DESIGN AND METHODS
Age- and sex-matched participants with normal glucose regulation (NGR), prediabetes, or diabetes diagnosed within 5 years, asymptomatic of coronary artery disease (CAD), were randomly selected from a community-dwelling Chinese population aged 40–60 years. Dual-source computed tomography coronary angiography was used to evaluate the existence and extent of coronary stenosis, which was considered significant if &gt;50% narrowing of vessel lumen was detected.

RESULTS
After excluding uninterpretable segments attributable to motion artifacts, a total of 135 participants with NGR, 132 with prediabetes, and 134 with diabetes participated in data analysis. Significant coronary stenosis was detected in 10 (7.4%), 10 (7.6%), and 22 (16.4%) individuals with NGR, prediabetes, and diabetes, respectively (P for trend = 0.029). Diabetes, rather than prediabetes, was associated with a significant 2.34-fold elevated risk [odds ratio (OR) 2.34 (95% CI 1.01–5.43); P = 0.047] of significant coronary stenosis as compared with that associated with NGR. Levels of glucose evaluation were independently and significantly associated with risks of significant coronary stenosis in diabetes. Each 1-SD increase in fasting plasma glucose, 2-h postload plasma glucose, and HbA1c conveyed 2.11-fold, 1.73-fold, and 1.81-fold higher risks of significant coronary stenosis, respectively, after adjustment for other conventional cardiovascular risk factors.

CONCLUSIONS
Using a noninvasive CAD diagnostic modality such as dual-source computed tomography coronary angiography, we detected a markedly elevated risk of significant coronary stenosis with early diabetes in asymptomatic Chinese adults.
Targeting the somatostatin receptors as a therapeutic approach for the preservation and protection of the mammalian cochlea from excitotoxicity
Authors: Radojevic Vesna , Brand Yves , Levano Soledad , Setz Cristian , Bodmer Daniel 
Published: March 2013

AbstractThe neuropeptide somatostatin (SST) is an important modulator of neurotransmission in the central nervous system (CNS) and binds to G-protein-coupled receptors (SSTR1-5) on target cells. Little is known about the expression and function of the somatostatinergic system in the mammalian cochlea. We analyzed the expression of SSTR1-SSTR5 in the immature mammalian cochlea. The peak in the expression of SSTR1 and SSTR2 at mRNA and protein level is around the onset of hearing to airborne sound, at postnatal day (P)14. This suggests their involvement in the maturation of the mammalian cochlea. We demonstrated that all five receptors are expressed in the inner hair cells (IHC) and outer hear cells (OHC) as well as in defined supporting cells of the organ of Corti (OC) in the adult mouse cochlea. A similar expression of the SSTRs in the IHC and OHC was found in cultivated P6 mouse OC explants as well as in neuroepithelial cell culture. In order to learn more about the regulation of SSTRs, we used mice with either a deletion of SSTR1, SSTR2 or SSTR1/SSTR2 double knock out (DKO). In DKO mice, SSTR5 was up-regulated and SSTR3 and SSTR4 were down regulated. These findings provide evidence of a compensatory regulation in the mammalian cochlea as a consequence of a receptor subtype deletion. In addition, we observed reduced levels of phospho-Akt and total-Akt in SSTR1 KO and DKO mice as compared to wild type (WT) mice. Akt is likely to be involved in hair cell survival. Most importantly, we found improved hair cell survival in somatostatin and octreotide treated OC explants that had been exposed to gentamicin compared to those explants exposed to gentamicin alone. These findings propose that the somatostatinergic system within the cochlea may have neuroprotective properties.
Reassessment of teratogenic risk from antenatal ultrasound
Authors: Williams Emily , Casanova Manuel 
Published: March 2013

AbstractScience has shown that risk of cavitation and hyperthermia following prenatal ultrasound exposure is relatively negligible provided intensity, frequency, duration of exposure, and total numbers of exposures are safely limited. However, noncavitational mechanisms have been poorly studied and occur within what are currently considered “safe” levels of exposure. To date, the teratogenic capacity of noncavitational effectors are largely unknown, although studies have shown that different forms of ultrasound-induced hydraulic forces and pressures can alter membrane fluidity, proliferation, and expression of inflammatory and repair markers. Loose regulations, poor end user training, and unreliable ultrasound equipment may also increase the likelihood of cavitation and hyperthermia during prenatal exposure with prolonged durations and increased intensities. The literature suggests a need for tighter regulations on the use of ultrasound and further studies into its teratogenicity.
Reviews
Authors: Zimmerman Alfred , Brett  , Beach Joseph Warren 
Published: March 2013

War Memoirs of David Lloyd George, vols. I and II, reviewed by Alfred Zimmerman Lord Riddell's War Diary, reviewed by Alfred Zimmerman J. A. Spender and Cyril Asquith, The Life of Herbert Henry Asquith, Lord Oxford and Asquith, vols. I and II , reviewed by Alfred Zimmerman W. R. Inge, God and the Astronomers, reviewed by G. S. Brett Pelham Edgar, The Art of the Novel, reviewed by Joseph Warren Beach
Reviews
Authors: Bentley Jr.  , Leggatt Alexander , Shaw W. David 
Published: March 2013

Geoffrey Keynes, ed., The Letters of William Blake, reviewed by G.E. Bentley Jr. William Blake, The Gates of Paradise: For Children, For the Sexes, reviewed by G.E. Bentley Jr. Geoffrey Keynes, ed., Europe: A Prophecy, reviewed by G.E. Bentley Jr. Geoffrey Keynes, ed., Songs of Innocence and of Experience, reviewed by G.E. Bentley Jr. Anne Malcolmson, ed., William Blake: An Introduction, reviewed by G.E. Bentley Jr. David V. Erdman, ed., A Concordance to the Writings of William Blake, reviewed by G.E. Bentley Jr. B.N. De Luna, Jonson's Romish Plot: A Study of Catiline and its Historical Context,reviewed by Alexander Leggatt Roma A. King Jr., The Focusing Artifice: The Poetry of Robert Browning, reviewed by W. David Shaw Mary Rose Sullivan, Browning's Voices in the Ring and the BOok: A Study in Method and Meaning, reviewed by W. David Shaw Elvan Kintner, ed., The Letters of Robert Browning and Elizabeth Barrett Barrett 1845–1846, reviewed by W. David Shaw
Reviews
Authors: Brady  , Walker Eric , Barker Ernest , Humphrey John 
Published: March 2013

Robert Laird Borden, Robert Laird Borden: His Memoirs, reviewed by A. Brady G. M. Wrong, The Canadians: The Story of a People, reviewed by Eric A. Walker A. S. P. Woodhouse, ed., Puritanism and Liberty: Being the Army Debates (1647–9) from Clarke Manuscripts, with supplementary documents, reviewed by Ernest Barker H. F. Angus, ed., Canada and Her Great Nieghbor,reviewed by John P. Humphrey Lionel M. Gelber, The Rise of Anglo-American Friendship, reviewed by John P. Humphrey
Panorama des jeux vidéo
Authors: Berthier Bruno , Parisot Lucie 
Published: March 2013

Dans cet article, les auteurs proposent tout d’abord de parcourir l’histoire des jeux vidéo, en faisant ressortir certains faits censés marquer leur évolution dans l’histoire numérique. Puis ils s’intéressent à des genres plus précisément en lien avec la dimension clinique, notamment par la présentation de quatre jeux, représentant chacun un style particulier, tant par leur mode de fonctionnement que par le type de joueurs qu’ils rassemblent : Counter Strike, World of Warcraft, League of Legends, Dofus.
Accuracy of Abduction-External Rotation MRA Versus Standard MRA in the Diagnosis of Intra-articular Shoulder Pathology
Authors: Modi Chetan S. , Karthikeyan Shanmugam , Marks Avi , Saithna Adnan , Smith Christopher D. , Rai Santosh B. , Drew Stephen J. 
Published: March 2013

The goal of this study was to compare the accuracy of abduction-external rotation magnetic resonance arthrography (ABERMRA) with standard MRA in the diagnosis of intra-articular shoulder pathology.
One hundred three consecutive patients undergoing preoperative direct MRA and subsequent arthroscopic examination were included in the study. Seventy-eight patients underwent standard MRA and 25 underwent ABERMRA. Specialist-trained musculoskeletal radiologists reported all scans, and attending shoulder surgeons performed all arthroscopies. Arthroscopic assessment revealed 11 partial-thickness rotator cuff tears, 3 full-thickness tears, 64 labral lesions (48 soft tissue and 16 significant bony), and 17 superior labrum anterior-posterior (SLAP) tears. The sensitivity/specificity for standard MRA was 0.56/0.99 for partial-thickness rotator cuff tears, 1.00/1.00 for full-thickness rotator cuff tears, 0.75/0.91 for soft tissue labral tears, 0.58/1.00 for significant bony glenoid lesions, and 0.50/0.91 for SLAP tears. Abduction-external rotation magnetic resonance arthrography increased the sensitivity/specificity to 1.00/0.85 for soft tissue labral tears, 0.75/1.00 for significant bony glenoid lesions, and 1.00/1.00 for SLAP tears, although it missed 2 of 2 partial-thickness rotator cuff tears.
This study suggests that standard MRA is a valuable investigation tool for instability, SLAP tears, and rotator cuff tears, although limitations exist. Additional ABERMRA sequences appear to improve the diagnostic accuracy of soft tissue anterior and posterior labral tears, SLAP tears, and significant bony glenoid lesions and should be routinely requested by shoulder surgeons when ordering MRAs to obtain the maximum benefit from this invasive investigation.
An Analog of Einstein’s General Relativity Emerging from Classical Finite Elasticity Theory: Analytical and Computational Issues
Authors: Cherubini C. , Filippi S. 
Published: March 2013

AbstractThe “analogue gravity formalism”, an interdisciplinary theoretical scheme developed in the past for studying several non relativistic classical and quantum systems through effective relativistic curved space-times, is here applied to largely de-formable elastic bodies described by the nonlinear theory of solid mechanics. Assuming the simplest nonlinear constitutive relation for the elastic material given by a Kirchhoff-St Venant strain-energy density function, it is possible to write for the perturbations an effective space-time metric if the deformation is purely longitudinal and depends on one spatial coordinate only. Theoretical and numerical studies of the corresponding dynamics are performed in selected cases and physical implications of the results obtained are finally discussed.