bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laboratory Investigation into Wettability Alteration by different Low Salinity Water Compositions in Sandstone Rock
Authors: Shabib-Asl A. , Ayoub M. A. , Elraies K. A. 
Published: October 2015

Abstract
Low salinity water flooding is not an infant practice in petroleum industry; in fact, it has prevailed for several decades. Due to its significant contribution to the hydrocarbon recovery, the method has widely gained the attention of many researchers. From its early breakthrough, many studies have been conducted which have focused on comparative analysis between the low and high salinity water. Moreover, it has been verified that most of them were effective at brine concentration below 5000 ppm. With the purpose of enhancing oil recovery, low salinity water (LSW) with adequate composition and salinity is injected into the reservoir, which changes the wetting properties of the reservoir rock into those favoring oil recovery. However, the true mechanisms behind the process are still questionable and there is no specific optimum salinity range and type to be recommended.
The present study investigates the wettability alteration on Berea sandstone rock with brine of different ion compositions and salinities. Measurements were performed on a set of 31 sandstone core slices primarily saturated with formation water and then aged in crude oil at 80° C and ambient pressure. All slices were removed from oil and aged with different low salinity water and formation brine at same conditions. The low salinity water consisted of 30 samples of different compositions with concentrations ranging from 500 to 6500 ppm. The formation water contained high concentration of magnesium and calcium divalent ions (i.e., Mg+2 and Ca+2) at 130,000ppm. The examination of wettability alteration was performed by using the sessile drop method at specified ranges of time. The results revealed that significant change in wettability was observed with the low salinity water composition of potassium and sodium monovalent ions (i.e., K+ and Na+) as compared to the divalent cations of Mg+2 and Ca+2.
CGDS Near-Bit Geosteering Drilling System and Its Application in China
Authors: Gao Wenkai , Sheng Limin , Dou Xiurong , Zhang Lei , Su Yinao , Wang Jiajin , Deng Le , Li Lin 
Published: October 2015

Abstract
Directional wells and cluster wells have become a conventional drilling technique now, which is widely used in various types of oil and gas reservoirs. Each year, more than half of the total drilling are directional wells in China. The main work is not to aim the target area, but to track the reservoirs now. Geosteering drilling is an important technical approach to improve single-well production and recovery ratio, to achieve the "less wells more production" idea.
China Geosteering Drilling System (CGDS), integrated the technology of drilling with logging and reservoir engineering, applies the near-bit geological and engineering parameters as well as controlling method to ensure that the wellhole trajectory can pass through reservoir and get best location while drilling. The wellhole trajectory can be adjusted and controlled timely according to the formation features measured by CGDS. The drilling bit is equipped with "eyes", which can identify oil/gas layer during drilling.
The CGDS is configured with CAIMS(Adjustable Instrumented Motor System), WLRS(Wireless Receiver System), GGMWD(Geosteering MWD System), CFDS(China Formation/Drilling Software System). More than 140 wells in China have demonstrated the system's ability to increase the probability of penetration and recovery rate in complicated formation, to reduce drilling costs and increase production and economic profit.
On the basis of introduction to the system, this paper focuses on the recent achievements as well as the lessons learned from the application in China. Helpful case histories will also be presented.
A Comprehensive Real-Time Multiphase Hydrodynamic Model for Kick Control While Managed Pressure Drilling and the Monitoring System
Authors: Zhou H. , Niu X. , Wang G. , Fan H. , Liu J. , Ma D. 
Published: October 2015

Abstract
Managed pressure drilling (MPD) technique can stop and remove a kick without shutting the well in while a kick was detected. But the key for a successful kick removal operation depend on accurate, real-time knowledge of downhole hydraulics. This paper proposed a comprehensive real-time multiphase hydrodynamic model for calculating hydraulics to be used to stop a kick during MPD on basis of logging equipment, PWD and Controler data and real-time control parameters. It can conduct a real-time calculating and monitoring hydraulic parameters using in the process of MPD.
First, according to the problem of non-unified data units and the mode of data sharing, transmission during the well logging PWD and Controler data transmission, an integrated new well site software module was developed, which combined the functions of data acquisition, transportation and simulation from different devices. This module puts the variability of the real-time data collection equipment, complicity of I/O ports, and specialty of transmission protocol outside the real-time computation module which is efficient and simple. Second, a real-time multiphase hydrodynamic model was established hydraulic calculation method was established, in which the flow channel both in pipe and annuli was divided into several sections, through which the different diameter of the channels were considered. And in each section the temperature and pressure dependent properties of multiphase fluid were taken into account. A series of system software were developed to predicted flow patterns, circulating pressures, gas top, bottomhole hydraulics and the related control parameters for control the kick while MPD.
The application of this system in Zhongyuan Oilfield of China show it can exactly monitoring multiphase hydraulics and the control parameters for control the kick while MPD. And it runs smoothly with convenient operation. Therefore it can be seen this system can be applied to provide more convenient fast and precise dynamic parameters monitoring for control kick while MPD.
Comparison of Pressure Transient Response in Intensely and Sparsely Fractured Reservoirs
Authors: Johns R. T. , Jalali-Yazdi Y. 
Published: October 2015

ABSTRACT
A comprehensive analytical model is presented to study the pressure transient behavior of a naturally fractured reservoir with a continuous matrix block size distribution. Geologically realistic probability density functions of matrix block size are used to represent reservoirs of varying fracture intensity and uniformity. Transient interporosity flow is assumed and interporosity skin is incorporated.
Drawdown and interference pressure transient tests are investigated. The results show distinctions in the pressure response from intensely and sparsely fractured reservoirs in the absence of interporosity skin. Also, uniformly and nonuniformly fractured reservoirs exhibit distinct responses, irrespective of the degree of fracture intensity. The pressure response in a nonuniformly fractured reservoir with large block size variability, approaches a nonfractured (homogeneous) reservoir response. Type curves are developed to estimate matrix block size variability and the degree of fracture intensity from drawdown and interference well tests.
Injection Time Effects on Falloff Responses From Composite Reservoirs
Authors: Ambastha A. K. , Ramey H. J. 
Published: October 2015

ABSTRACT
A radial, composite reservoir idealization is used to analyze falloff tests from enhanced oil recovery projects such as thermal recovery, and CO2 flooding. Swept volume (or front radius) is a primary parameter to monitor the progress of a project. A falloff test is an inexpensive way to obtain an estimate of swept volume (or front radius). Either deviation time from a semi-log line corresponding to the inner region mobility, or a short duration pseudosteady state behavior corresponding to the inner region swept volume, or type-curve matching may be used to analyze the data. Any of these methods would produce an inaccurate estimate for swept volume (or front radius), if injection time is short. To the best of our knowledge, injection time effects on falloff responses for a well in a composite reservoir have not been presented in the literature.
Using an analytical solution, this study establishes dimensionless injection time based on front radius as a correlating parameter for falloff responses for all front radii. Effects of short injection time on the accuracy of the methods to estimate swept volume (or front radius) are discussed. If injection time effects are ignored, the pseudosteady state method may overestimate swept volume by an order of magnitude. For short injection times, model selection (a two-region vs. a three-region model) for type-curve matching can be difficult. Finally, a correlation is presented for the magnitude of injection time to analyze falloff data using an injectivity type-curve.
Effects of Pipe Roughness on Friction Pressures of Fracturing Fluids
Authors: Shah S. N. 
Published: October 2015

ABSTRACT
During hydraulic fracturing treatments, fracturing fluid is pumped down the well in turbulent flow through commercially available rough iron pipes. Pipe roughness contributes largely to friction loss or friction pressure in turbulent flow. Methods have previously been presented to estimate friction loss of fracturing gels (non-Newtonian) in turbulent flow in smooth pipes, but not for rough pipes.
In this study the effects of pipe roughness on friction pressures of uncrosslinked as well as crosslinked fracturing gels are reported from flow data gathered in smooth and rough pipes. It is found that pipe roughness effects are very significant when estimating friction pressures of fracturing fluids. These effects are more pronounced with less viscous fluids than with more viscous fluids, and are also more pronounced at higher rates with both fluids. From the data gathered with fluids tested in this study, correlations to estimate friction pressures of fracturing gels in turbulent flow in rough pipes are also presented. Though not ideal, these correlations allow better estimates of friction pressures in rough tubular conductors than do existing methods.
An Analytical Model for History Matching Naturally Fractured Reservoir Production Data
Authors: Watson A. T. , Gatens J. M. , Lee W. J. , Rahim Z. 
Published: October 2015

Abstract
A method to estimate reservoir properties and predict future performance using production data for naturally fractured reservoirs is presented. The method uses an analytical solution describing dual-porosity reservoirs with constant bottomhole pressure production in both infinite-acting and finite reservoirs. The solution is rigorous for slightly compressible liquid flow, and it is modified using a normalized time to model gas flow in finite reservoirs.
A method is presented for analyzing production data. The method includes procedures for validating the dual-porosity model with production data, determining the suitability of simpler reservoir models, and determining the "best" parameter estimates for the selected model. Example applications using field data from naturally fractured reservoirs are presented.
The Analysis of Pressure Transient Data From Underbalanced Perforating
Authors: Garrett J. C. , Shealy R. A. , Centanni R. J. , Ruiz S. J. , Chacon E. A. 
Published: October 2015

ABSTRACT
Determination of reservoir characteristics from formation pressure created by underbalanced perforating may enable an operator to decide whether a well is commercially productive prior to permanent completion. With the use of several existing techniques, it is possible to analyze such data.
With closed chamber testing techniques, wellhead pressures are used to calculate variable sandface rates during and shortly after the well is underbalance perforated. Superposition is employed to create a rate-time function for plotting with bottom hole pressure data. The straight-line portion of the pressure versus ratetime function plot can be fitted using linear regression to solve the radial flow equation. Calculated parameters include effective permeability, skin effects and initial reservoir pressure.
Also presented, is a method proposed by Soliman to analyze short producing time data. Delta pressure versus total time data is plotted on a Log-Log graph where the time axis combines producing time with build up time. A negative one (−1) slope on this plot indicates the existence of radial flow, from which reservoir characteristics can be calculated if the flow regime is known. A cartesian plot can be used to estimate initial reservoir pressure.
This paper illustrates the use of the aforementioned techniques on data collected from a multi-well project in the Gulf of Mexico. Analyses of oil wells were investigated. The results of these analysis methods for oil cases are compared with buildups performed after the wells were completed.
These analysis techniques have also been applied to formation back surge data with similar results.
Clay Stabilization in Low-Permeability Formations
Authors: Himes R. E. , Vinson E. F. , Simon D. E. 
Published: October 2015

ABSTRACT
Clay stabilizers have been used in various forms in oil well treating solutions for over 30 years. Cationic organic polymers have been the most popular type stabilizer in use recently because of their resistance to wash-off and chemical attack, ease of application, and effectiveness in moderate to high permeability formations. Recent studies investigating the effectiveness of such stabilizers in very low to low permeability sandstones have shown them to be less than 100% effective in stabilizing clays to prevent swelling and migration. Results indicate that higher molecular weight polymers can create permeability impairment when injected into these formations. These findings indicated the need for further research into clay stabilizers. This research led to the development of a novel clay stabilizing chemical for low, as well as high, permeability formations. This low permeability clay stabilizer also offers additional benefits in treating low permeability formations by enhancing fluid recovery after fracturing, and preventing the detrimental effects of fracturing fluid gel adsorption onto formation surfaces.
Éloge de la flexibilité des leaders
Authors: Baron Louis 
Published: October 2015

Il est de bon ton de dire que le gestionnaire et l’entrepreneur vivent sur des planètes différentes 1 . Mais qu’en est-il du gestionnaire et du leader ? Et s’il était possible pour une personne d’assumer ces deux rôles avec harmonie et efficacité ? Les gestionnaires désireux de mieux comprendre les multiples paradoxes associés à leur rôle devraient explorer la notion de « leadership flexible ».
La fonction RH : superflue ou essentielle ?
Authors: Weidmann Jean , Sabourin Francine 
Published: October 2015

Longtemps reconnu comme un élément clé des organisations, le service des Ressources Humaines (RH) est aujourd’hui dans la mire de plusieurs réflexions, dont celle présentée par le professeur Jean Weidmann. Que font les RH à part gérer le processus de la paie et les contrats d’embauche ? Quelle est la valeur ajoutée de ce service ? Voilà des questions auxquelles la direction de l’ordre des conseillers en ressources humaines offre bien des réponses. Le débat est ouvert !
L’inadéquation du mobile
Authors: Dussart Christian 
Published: October 2015

La course à la technologie est telle que bon nombre d’experts y voient la solution miracle à tous les problèmes que nous rencontrons, quels que soient les domaines. Toutefois, cela pose problème : cette vision est non seulement péremptoire mais aussi biaisée puisqu’elle est centrée sur ses seuls bienfaits possibles. Nous en oublions que ce qui fait marcher le monde de l’économie et du social, ce sont les réactions qu’elle suscite chez les êtres humains. Si nous recentrons alors la réflexion de départ sur eux, nous nous rendons compte que les choses ne sont pas aussi simples et encore moins aussi évidentes qu’elles en ont l’air : c’est le revers de la médaille. C’est l’inadéquation du mobile.
Ranibizumab versus Bevacizumab for the Treatment of Idiopathic Choroidal Neovascularization: 2-Year Results
Authors: Zhou Pengyi , Yang Lin , Jin Xuemin 
Published: October 2015

Purpose To compare the efficacy and safety of bevacizumab vs ranibizumab for the treatment of idiopathic choroidal neovascularization (ICNV). Methods This retrospective study included 60 eyes of 60 patients with ICNV who underwent intravitreal injection of bevacizumab (1.25 mg/0.05 mL, n = 30 eyes) or ranibizumab (0.5 mg/0.05 mL, n = 30 eyes). Multiple treatments were based on complete ophthalmologic investigation including slit-lamp biomicroscopy, fundus examination, fundus fluorescein angiography (FFA), optical coherence tomography (OCT), and best-corrected visual acuity (BCVA). The BCVA, central retinal thickness (CRT), intraocular pressure (IOP), FFA results, and complications were compared between the 2 groups during the 2-year follow-up. Results Visual acuity was significantly better at 1, 3, 6, 12, and 24 months after treatment (p<0.01), with no significant difference in visual acuity between the bevacizumab and ranibizumab groups. In both groups of patients, the CRT after treatment was significantly less than before. At 12 and 24 months, the CRT in the ranibizumab group was significantly less than in the bevacizumab group (p<0.05). The FFA examination showed that CNV was reduced after intravitreal injection of either drug, with no significant difference in IOP between the 2 groups. No ophthalmologic or systemic complications occurred. Conclusions Bevacizumab and ranibizumab are effective and safe in the treatment of ICNV, with similar effects in improving visual acuity and reducing retinal edema. The long-term efficacy of ranibizumab is superior to bevacizumab in reducing CRT.
Comparing Changes in Plasma and Skin Autofluorescence in Low-Flux versus High-Flux Hemodialysis
Authors: Ramsauer Bernd , Engels Gerwin , Arsov Stefan , Hadimeri Henrik , Sikole Aleksandar , Graaff Reindert , Stegmayr Bernd 
Published: October 2015

Background Tissue advanced glycation end products (AGE) are increased in hemodialysis (HD) patients, especially those with cardiovascular complications. Skin autofluorescence (skin-AF) can noninvasively estimate the accumulation of AGE in tissue. The aim was to clarify whether HD using a high-flux (HF) dialyzer favors plasma- or skin-AF removal compared to low-flux (LF) dialysis. Material and methods 28 patients were treated with either an HF-HD or LF-HD but otherwise unchanged conditions in a cross-over design. A glucose containing dialysate was used. Skin-AF was measured noninvasively with an AGE reader before and after HD. Fluorescence (370 nm/465 nm) of plasma (p-AF) was determined as total and nonprotein-bound fractions. Correction for hemoconcentrations were made using the change in serum albumin. Paired and nonpaired statistical analyses were used. Results Skin-AF was unchanged after LF- and HF-dialysis. Total, free, and protein- bound p-AF was reduced after a single LF-HD by 21%, 28%, and 17%, respectively ( P<.001). After HF HD total and free p-AF was reduced by 5% and 15%, respectively ( P<.001), while protein bound values were unchanged. The LF-HD resulted in a more pronounced reduction of p-AF than did HF HD ( P<.001). Serum albumin correlated inversely with p-AF in HF-HD. Conclusions In the dialysis settings used there was no significant change in skin AF after dialysis, with LF or with HF dialysis. Although only limited reduction in plasma fluorescence was observed, this was more pronounced when performing LF dialysis. These data are not in overwhelming support of the use of HF dialysis in the setting used in this study.
A Neuro-Oncologic Challenge: The Case of a Large, Aggressive, Malignant Meningioma of the Skull Base with Paranasal Sinus Involvement
Authors: Ghirardelli Paolo , Triggiani Luca , Pedretti Sara , Bonetti Fausta , Liserre Roberto , Gipponi Stefano , Panciani Pierpaolo , Buttolo Luciano , Grisanti Salvatore , Urpis Mauro , Spiazzi Luigi , Magrini Stefano Maria , Buglione Michela 
Published: October 2015

Background Malignant meningiomas, rare tumors that account for approximately 1%-3% of all meningioma, have high recurrence, morbidity, and mortality rate and a particularly poor outcome. Surgical excision followed by adjuvant radiotherapy is the current approach for the treatment of these tumors. Methods In the case reported, the disease, characterized by a high proliferative index (Ki67 60%-70%), was treated with endoscopic surgery limited to the extracranial portion; then the patient underwent radiotherapy, on the residual tumor volume, to a total dose of 66 Gy delivered in 33 fractions (2 Gy/fraction) by helical intensity-modulated radiation therapy with image-guided radiotherapy daily checks (tomotherapy). Results Two and a half years after the treatment, the patient is alive and a partial response is maintained. The patient is healthy overall with grade I fatigue and grade II hearing loss as late toxicity (Common Terminology Criteria for Adverse Events 4.1). Conclusions Within a multidisciplinary approach, new radiotherapy techniques confirm their effectiveness and reliability for the treatment of malignant meningioma.
Neither dust nor black carbon causing apparent albedo decline in Greenland's dry snow zone: Implications for MODIS C5 surface reflectance
Authors: Polashenski Chris M. , Dibb Jack E. , Flanner Mark G. , Chen Justin Y. , Courville Zoe R. , Lai Alexandra M. , Schauer James J. , Shafer Martin M. , Bergin Mike 
Published: October 2015

AbstractRemote sensing observations suggest Greenland ice sheet (GrIS) albedo has declined since 2001, even in the dry snow zone. We seek to explain the apparent dry snow albedo decline. We analyze samples representing 2012–2014 snowfall across NW Greenland for black carbon and dust light‐absorbing impurities (LAI) and model their impacts on snow albedo. Albedo reductions due to LAI are small, averaging 0.003, with episodic enhancements resulting in reductions of 0.01–0.02. No significant increase in black carbon or dust concentrations relative to recent decades is found. Enhanced deposition of LAI is not, therefore, causing significant dry snow albedo reduction or driving melt events. Analysis of Collection 5 Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance data indicates that the decline and spectral shift in dry snow albedo contains important contributions from uncorrected Terra sensor degradation. Though discrepancies are mostly below the stated accuracy of MODIS products, they will require revisiting some prior conclusions with C6 data.
Forks in the Road: Memories of Turning Points and Transitions
Authors: Enz Karalyn F. , Talarico Jennifer M. 
Published: October 2015

SummaryTurning points and transitions are both life events marked by significant change. Whereas turning points are personal changes in life direction, transitions are external changes in daily circumstances. Transition‐linked turning points are events that fit both of these definitions. Although transitions and turning points have been examined separately, the current study is the first empirical comparison of these types of events and their overlap. Differences in the characteristics of adults' autobiographical memories of turning points, transitions, and transition‐linked turning points were compared using a within‐subjects design. Memories of transition‐linked turning points and turning points were more central to participants' life stories than transitions, whereas memories of transitions had more similarities in content, particularly location, with related memories. These results suggest that transitions organize autobiographical memory whereas turning points anchor the life story. Copyright © 2015 John Wiley & Sons, Ltd.