bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wellbore Remediation using Microemulsion Technology to Increase Hydrocarbon Productivity
Authors: Darugar Qusai A. , Quintero Lirio , Jones Thomas A. , Pietrangeli Gianna 
Published: April 2012

Abstract
Decreases in hydrocarbon production can be attributed to depletion in formation pressures or flow restrictions caused by formation damage. Some of the most common causes of formation damage affecting permeability include the buildup of in-situ emulsions due to crude oil interaction with drilling and completion fluids, water blockage, asphaltene and paraffin deposition and alteration of near-wellbore wettability. In new wells, near-wellbore formation damage may be caused by emulsion blockages when the whole mud, mud filtrate or completion fluids interact with the formation fluids.
Chemical treatments have been widely used to remediate damaged formations, with varying degrees of effectiveness. Single-phase microemulsion fluids provide unique properties that can effectively remove emulsion blockages, remove precipitated crude oil macromolecules, and reverse wettability to enhance hydrocarbon production. Carefully designed microemulsion systems having an ultra-low interfacial tension, high solvency and compatibility with formation fluids can be used to mobilize fluids and solids in wells.
This paper discusses the process of developing and qualifying a single-phase, temperature stable microemulsion system for field applications. Case history results are presented that demonstrate how this technology, if applied properly, can significantly enhance hydrocarbon production in poorly producing wells.
Casing Drilling Technology Application: Case Histories from Saudi Arabia
Authors: Chima Jude , Zhou Shaohua , Al-Hajji Ali , Okot Mike , Sharif Qamar J. , Clark David , Oveson Dale , Moellendick Eric , Holt Calvin , Neidhardt Dietmar 
Published: April 2012

Abstract
Casing-while-drilling is a relatively new well construction process or technology for simultaneously drilling and casing a wellbore, and has been utilized globally over the last 15 years or so. This technology has shown advantages of reducing overall drilling time and cost. It has demonstrated signs of reducing hole problems, such as mud losses, through plastering effect because of the rotation of the casing string against the formation. It provides assurance to case off unstable formations while drilling, resulting in significantly reduced well construction costs.
Saudi Aramco has made several field test runs of this technology beginning in early October 2008, including deployments of both simple casing drilling with drill-through casing bit (non-retrievable) system and advanced bottom hole assembly (BHA) retrievable system designed for directional casing drilling. This paper will document the lessons learned from implementation of the technology, including planning and design, rig operations, problems encountered, modifications made to reduce risk after extensive review and investigation, and finally, successful deployment of a directional casing drilling to the planned casing point with a 17" x 13-⅜" system. In addition, the paper briefly outlines the further required improvements of casing drilling tools to ensure continued success in the future.
Quality Control/Quality Assurance Assessments of Core Analysis Data from Multiple Commercial Laboratories
Authors: Amabeoku Maclean O. , BinNasser Rami H. 
Published: April 2012

Abstract
Hydrocarbon in place calculations and recovery predictions require data from a variety of sources. Of these sources, core data are, potentially, the most accurate because they are direct measurements. Therefore, reliable and representative core analysis data are essential to calibrate and validate tool-acquired data, especially, wireline logs. Special core analysis (SCAL) vendor laboratories are the primary sources or supplemental resources for the measurements and acquisition of core data. These laboratories are set up for more rapid throughput of large quantities of samples at costs lower than those of an oil company's internal laboratory. But very poor quality data can be generated by some vendors.
This paper discusses Quality Control/Quality Assurance analysis and assessments of SCAL data from four laboratories. The multi-vendor SCAL program was formulated to evaluate specific petrophysical properties capabilities of the selected laboratories. The tests included porosity and permeability at varying stress, formation water resistivity (Rw), electrical properties (m and n), and capillary pressure by the centrifuge and mercury intrusion methods.
Core plugs from two different formations were used in the evaluation. One set consisted of limestone plugs and the other set included sandstone samples. Baseline porosity and air permeability measurements and CT scans were used to screen the samples and divide them into subsets for the individual vendors. The only information provided to the vendors was plug designation.
Some laboratories provided very poor quality data on some of the tests. They reported wrong results for porosity at varying stress, electrical properties, and mercury capillary pressure. Probe maintenance, contamination, and calibration were given as possible reasons for erroneous brine resistivity. Wrong saturation exponent values were attributed to saturation instability.
The errors identified in this study can have significant economic impact on a field development program. Therefore, it is important that we exercise very strict supervision of the program and engage with the vendor throughout the data acquisition program. The QC/QA analysis used in this study can improve the performance of these vendors and the quality of data.
Correlations Between NMR Relaxation Response and Relative Permeability From Tomographic Reservoir Rock Images
Authors: AlGhamdi Tariq M , Arns C. H. , Eyvazzadeh R. Y. 
Published: April 2012

Abstract
NMR is typically used in the petroleum industry to characterize pore size and identify fluids in fully and partially saturated reservoir samples. While the NMR relaxation response can be used to estimate the permeability of the rock, it may also provide information about fluid distribution for multi-phase systems which would lead to the estimation of effective permeability of fluids at partial saturations and derivation of relative permeability to assess hydrocarbon recovery. Using a random walk method, we simulate the NMR response as function of saturation on tomographic images of Bentheimer and Berea sandstone as well as a Ferroan Dolomite samples. Fluid distributions are simulated using the capillary pressure curves of these samples via capillary drainage transform (CDT) allowing the calculations of the saturations directly on the images. The magnetic susceptibility of minerals and fluids is used to calculate the internal magnetic fields from the material distributions of solids and fluids. We show that the logarithmic mean of the NMR T2 distribution is a robust measure of permeability and results in strong correlations between NMR response and relative permeability of both fluids. The observed relative permeability from NMR in our work is in excellent agreement with relative permeability calculations on direct image based using the lattice Boltzmann method (LBM). We have also compared our NMR results for the wetting phase to published experimental results on Bentheimer and Berea sandstone samples and observed strong agreement. Using NMR numerical calculations, we demonstrate that internal gradients aid the establishment of relative permeability correlations for the non-wetting phase.
Laboratory Scale Control of Drilling Parameters to Enhance Rate of Penetration and Reduce Drill String Vibration
Authors: Esmaeili Abdolali , Elahifar Behzad , Fruhwirth Rudolf K. , Thonhauser Gerhard 
Published: April 2012

Abstract
Drill string vibration and shock loads are known as destructive loads while drilling and are the reason for tool failure, lost time and reduction in rate of penetration. Vibrations of drill strings can be effected by bit and bottom hole assembly design, interaction of bit/formation and drilling parameters. To manage vibration, however, weight on bit and rotary speed are the only means that can be changed by the driller while making a hole. Therefore it has been always tried to define an optimum range for drilling parameters as key components of the vibration reduction and the rate of penetration management process.
A fully automated laboratory scale drilling rig (CDC miniRig) and vibration sensor sub are used to monitor and record drilling parameters such as weight on bit, rotary speed and vibration of drill string among others.
Based on different ranges of weight on bit and rotary speed, drilling data and vibration readings are analyzed and the effects of drilling parameters due to vibrations are better understood.
Parameter ranges based on the experimental results leading to minimum vibration and optimum rate of penetration are presented.
Carbon Dioxide Sequestration: Modeling the Diffusive and Convective Transport under a CO2 Cap
Authors: Allen Rebecca , Sun Shuyu 
Published: April 2012

Abstract
A rise in carbon dioxide levels from industial emissions is contributing to the greenhouse effect and global warming. CO2 sequestration in saline aquifers is a strategy to reduce atmospheric CO2 levels. Scientists and researchers rely on numerical simulators to predict CO2 storage by modeling the fluid transport behaviour.
Studies have shown that after CO2 is injected into a saline aquifer, undissolved CO2 rises due to buoyant forces and will spread laterally away from the injection site under an area of low permeability. CO2 from this ‘capped’ region diffuses into the fluid underlying it, and the resulting CO2-fluid mixture increases in density. This increase in density leads to gravity-driven convection. Accordingly, diffusive-convective transport is important to model since it predicts an enhanced storage capacity of the saline aquifer.
This work incorporates the diffusive and convective transport processes into the transport modeling equation, and uses a self-generated code. Discretization of the domain is done with a cell-centered finite difference method. Cases are set up using similar parameters from published literature in order to compare results. Enhanced storage capacity is predicted in this work, similar to work done by others. A difference in the onset of convective transport between this work and published results is noticed and discussed in this paper.
A sensitivity analysis is performed on the density model used in this work, and on the diffusivity value assumed. The analysis shows that the density model and diffusivity value is a key component on simulation results. Also, perturbations are added to porosity and permeability in order to see the effect of perturbations on the onset of convection, and results agree with similar findings by others.
This work provides a basis for studying other cases, such as the impact of heterogeneity on the diffusion-convective transport. An extension of this work may involve the use of an equation of state to predict CO2 solubility at thermodynamic conditions, and studying the impact of salinity on CO2 solubility.
The Association of Mental Health over Time with Cardiac Outcomes in HEMO Study Patients
Authors: Kang Ea Wha , Pike Francis , Ramer Sarah , Abdel-Kader Khaled , Myaskovsky Larissa , Dew Mary Amanda , Unruh Mark 
Published: April 2012

Summary

Background and objectives
Poor mental health over time is significantly associated with cardiovascular morbidity and mortality in the general population, which is the leading cause of death in dialysis patients. Most studies of dialysis patients, however, have investigated the relationship between baseline mental health measurements and all-cause mortality and not mental health measured longitudinally throughout a study and cause-specific mortality.

Design, setting, participants, & measurements
This study examined the association of changes in mental health over time with all-cause and cause-specific deaths and cardiac hospitalizations in the Hemodialysis study patients. Mental health was assessed at baseline and annually during the study with short form 36 mental health index scores. Poorer mental health was defined by a mental health index score≤60.

Results
Patients with poorer mental health at baseline were more likely to have less than a high school education and be unmarried, have significantly higher index of coexistent disease scores, and report taking β-blockers and sleep medications. Low mental health scores over time were independently associated with a decrease in survival time from all-cause mortality by −0.06 (−0.10, −0.03; P<0.001), and they also significantly hastened time to first cardiac hospitalization by −0.08 (−0.13, −0.02; P=0.01) and composite of first cardiac hospitalization or cardiac death by −0.04 (−0.07, −0.02; P<0.001).

Conclusions
This study found an independent association between poor mental health over time and all-cause mortality, cardiac hospitalization, and the composite of cardiac death or cardiac hospitalization in hemodialysis patients. The results underscore the importance of attention to mental health related to cardiac complications and even death in dialysis patients.
Oligodendrorhynchus hesperides gen. et sp. n. (Heteronemertea) from the Bellingshausen Sea
Authors: Fernández-Alvarez Fernando , Anadón Nuria 
Published: April 2012

Oligodendrorhynchus hesperides gen. et sp. n. (Heteronemertea) from the Bellingshausen Sea
A new genus and species of heteronemertean from the Antarctic (Bellingshausen Sea), Oligodendrorhynchus hesperides, is described and illustrated. Some morphological features with major systematic significance are following: the mode of branching of the proboscis and its low number of terminal branches; the lack of horizontal lateral cephalic slits but in their place a pair of shallow epidermal depressions; a gelatinous amorphous connective stratum between the outer longitudinal and circular muscle layers; the presence of a rhynchocoelic nerve; isolated fibres of the rhynchocoel circular muscle layer interwoven with bundles of the adjacent body-wall inner longitudinal muscle fibres in the intestinal region. Other anatomical characters which can also be used to distinguish the new taxon from existing heteronemertean species that have a branched proboscis are also discussed.
Methodological problems of Assessing Spatial and Temporal Changes in the quality of Mine Water / Metodologické Problémy Hodnocení Prostorových A Časových Změn Kvality Důlních Vod
Authors: Rapantová Naďa , Grmela Arnošt 
Published: April 2012

Abstract
An important, but largely neglected hydrogeological issue is the timing of mine water sampling during mining and after mine closure. Significant temporal and spatial changes in the “ageing“ of information, neglected effects of dynamic changes in the quality of mine water and its resources are causing severe degradation of information from mine water analyses and their possible misleading interpretation. Hydrogeological data are typical examples of multi-parametric information and if any hydrogeochemical data bases and their further processing are to be undertaken it is advisable to use methods of multi-parametric analyses followed by hydrogeochemical reaction models. Another limiting factor affecting the validity of results is the assessment of the issue of the representativeness of samples. The methodology applied on various mining sites is widely discussed in the paper.
Application of Gpr During Investigation Concerning Causes of Failure of Railway Station Platform in Jilešovice / Využití Gpr Při Zjišťování Příčin Porušení Nástupiště Nádraží V Jilešovicích
Authors: Pospíšil Pavel , Poláček Aleš , Kovář Luděk 
Published: April 2012

Abstract
Civil engineering works carried out as the renovation of existing buildings can be difficult to predict in terms of their behaviour over time. The heterogeneity of materials of a natural and anthropogenic origin can subsequently lead to either deformations, or breach threatening the existence of building structure in terms of statics. The platform of the station in Jilešovice underwent structural modifications within the reconstruction of the railway track from Ostrava to Opava. The largest building intervention was the reconstruction of an old bridge and adjacent embankment bodies now in addition secured due to stability by gabion baskets instead of the original natural grading. After a short time of its use, significant deformations appeared on the renovated object, whose causes and further evolution over time was not known. Within the design of investigation techniques, allowing uncovering the causes of violation quickly and efficiently, the survey with a georadar -GPR (Ground Penetrating Radar) was included, which as an indirect, non-destructive method of survey very quickly helped to clarify the causes of violations of the building structures
Prevention of intraoperative cerebrospinal fluid leaks by lumbar cerebrospinal fluid drainage during surgery for pituitary macroadenomas
Authors: Mehta Gautam U. , Oldfield Edward H. 
Published: April 2012

Object
Cerebrospinal fluid leakage is a major complication of transsphenoidal surgery. An intraoperative CSF leak, which occurs in up to 50% of pituitary tumor cases, is the only modifiable risk factor for postoperative leaks. Although several techniques have been described for surgical repair when an intraoperative leak is noted, none has been proposed to prevent an intraoperative CSF leak. The authors postulated that intraoperative CSF drainage would diminish tension on the arachnoid, decrease the rate of intraoperative CSF leakage during surgery for larger tumors, and reduce the need for surgical repair of CSF leaks.

Methods
The results of 114 transsphenoidal operations for pituitary macroadenoma performed without intraoperative CSF drainage were compared with the findings from 44 cases in which a lumbar subarachnoid catheter was placed before surgery to drain CSF at the time of dural exposure and tumor removal.

Results
Cerebrospinal fluid drainage reduced the rate of intraoperative CSF leakage from 41% to 5% (p < 0.001). This reduction occurred in macroadenomas with (from 57% to 5%, p < 0.001) and those without suprasellar extension (from 29% to 0%, p = 0.31). The rate of postoperative CSF leakage was similar (5% vs 5%), despite the fact that intraoperative CSF drainage reduced the need for operative repair (from 32% to 5%, p < 0.001). There were no significant catheter-related complications.

Conclusions
Cerebrospinal fluid drainage during transsphenoidal surgery for macroadenomas reduces the rate of intraoperative CSF leaks. This preventative measure obviated the need for surgical repair of intraoperative CSF leaks using autologous fat graft placement, other operative techniques, postoperative lumbar drainage, and/or reoperation in most patients and is associated with minimal risks.
Intégrer les Tice à une approche cognitive de la grammaire du discours
Authors: Barbazan Muriel 
Published: April 2012

Si l'on a pour objectif de favoriser un apprentissage de la grammaire évaluable à l'aune des performances communicatives réelles des apprenants, il est utile d'identifier préalablement un cadre de travail qui respecte les processus cognitifs de production et de compréhension. Dans ce cadre, cet article envisage la question de la reformulation des contenus grammaticaux pour cibler l'apprentissage guidé de la langue telle qu'elle est mise en œuvre dans le "discours". Pour ce faire, on illustrera l'intérêt d'une démarche descriptive associant les deux pistes suivantes : a) intégrer à la description grammaticale des prototypes de situations d'interactions verbales en relation avec les significations données aux outils grammaticaux. Parallèlement, b) mettre en relation les fonctions des outils grammaticaux avec des types de plans textuels tout en insistant sur leur rôle de marqueurs de la macrostructure (repérage des unités textuelles). L'objet de cet article sera ensuite d'explorer les possibilités qu'offrent les Tice pour un apprentissage guidé ciblant l'acquisition de routines grammaticales adaptées à la production / réception du discours en situation. L'accent sera mis sur les activités de compréhension et de réorganisation unifiée des connaissances et savoir-faire grammaticaux, tout en soulignant l'intérêt des Tice pour favoriser en FLE la mise en œuvre effective et interactive de la L2. À partir d'exemples d'activités ou de possibilités d'exploitation de divers outils, cette seconde partie servira ainsi d'illustration aux axes descriptifs et aux orientations didactiques préalablement définis.
The Comic Nature of Ecce Homo
Authors: Meyer Matthew 
Published: April 2012

Abstract
This article argues that Nietzsche's 1888 writings should be understood as a Dionysian comedy that parallels important formal structures of Aristophanes' early plays. Whereas works such as The Twilight of the Idols and The Case of Wagner contain features that resemble the agonal elements of Dionysian comedy, Ecce Homo should be understood as a comic parabasis of self-definition.
The Kantian Background to Nietzsche's Views on Causality
Authors: Doyle Tsarina 
Published: April 2012

Abstract
This article addresses the Kantian background to Nietzsche's metaphysics. Focusing on the issues of causality and force, I argue that Nietzsche's will to power thesis emerges in response to Kant's approach to the question of causality. I contend that Nietzsche sides with Kant, contrary to Schopenhauer, in his identification of force with efficient causality, indicating his approval of Kant's restriction of the objective applicability of the concept of causality to the phenomenal sphere. However, Nietzsche contends that Kant fails to fully execute his project due to his retention of the thing-in-itself as the realm in which the inner determinations of things reside. I argue that Nietzsche makes it his task to complete the Kantian project by reconciling force with its disinherited inner determinations at the level of phenomena rather than things-in-themselves.