bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pressure Analysis of a Well with an Inclined Asymmetric Hydraulic Fracture Using Type Curves
Authors: Habte Azeb Demisi , Dinh Anh V. , Tiab Djebbar 
Published: September 2010

Abstract
Hydraulic fracturing is an effective well stimulation technique which is introduced in the 1950s and widely used in the oil and gas industry. Most of the works about hydraulic fracturing assumed that the fracture is symmetric and either vertical or horizontal. But, several field and laboratory observations show very complex fractures, inclined, multi-segmented, asymmetric, and multiple fractures.
The purpose of this study is to investigate the pressure behaviour of a uniform flux hydraulic fracture which is both inclined and asymmetric. This objective is achieved by using transient pressure and pressure derivative plots. Three cases are investigated; (a) the fracture is asymmetric only along the horizontal direction (X-axis), (b) the fracture is asymmetric only along the lateral direction (Y-axis), and (c ) the fracture is asymmetric along both horizontal and lateral directions.
Three flow regimes, Linear Flow Regime, Early-Radial Flow Regime, and Pseudo-Radial Flow Regime are observed when the asymmetry is not significant and for small θw and hD. As the asymmetry increases the behaviour the fracture also shows changes. For a fracture with high asymmetry, Bi-radial Flow Regime is observed in addition to the above flow regimes. As the asymmetry becomes significant the uniform flux fracture solution shows similar behaviour to infinite conductivity fracture.
Type curve matching technique was developed in this study using pressure and pressure derivative curves. This type curve matching technique can be used to obtain the following reservoir parameters: fracture half length, inclination angle, formation permeability and the pseudo-skin factor, caused by fracture inclination.
Investigating the Use of Nanoparticles in Enhancing Oil Recovery
Authors: Onyekonwu Mike O. , Ogolo Naomi A. 
Published: September 2010

Abstract
This paper is aimed at studying the ability of three different polysilicon nanoparticles (PSNP) to enhance oil recovery. Changing rock wettability is the target because wettability is a primary factor that affects recovery efficiency. The experiments conducted centered on laboratory coreflooding using two kinds of oil, brine and polysilicon nanofluids on water wet rocks obtained from the Niger Delta. The three kinds of PSNP used for this study were lipophobic and hydrophilic PSNP (LHPN), hydrophobic and lipophilic PSNP (HLPN) and neutrally wet PSNP (NWPN).
The results obtained indicate that NWPN and HLPN are good enhanced oil recovery (EOR) agents in water wet formations. Two mechanisms through which oil recovery is enhanced using NWPN and HLPN are change of rock wettability and reduction of interfacial tension by the improved quality of ethanol, the dispersing agent. Thus NWPN and HLPN dispersed in ethanol are recommended for use in EOR for water wet formations. LHPN which make already water wet rocks strongly water wet yield poor recovery factors indicating that its use for EOR should be restricted to oil wet formations.
An Applied High Temperature Sand Control Well Completion Technique for Horizontal Wells
Authors: Ruiyi Xu , Zhiqi Zhou , Xu Zhang 
Published: September 2010

Abstract
In last years, a number of horizontal wells has been drilled in Shengli Oilfield for increasing recoverable reserves, advancing economic benefits of new oilfield and developing previous unrecoverable resources, including extra-heavy oil in deep reservoir. Due to most of the heavy oil reservoirs are unconsolidated, it is needed to adopt the high temperature sand control completion technique to meet the requirements of the thermal recovery.
The high temperature pre-pack screen was used. It is a successful method for sand control, but the gravel liners breakdown easily while go through the bending intervals of the wells, thus, the effects and life of the liners will be decreased. In this case, a new metal-fiber screen was developed and used in 12 wells with different geological conditions. The success ratio for sand control reached 100%, and the oil production of individual wells achieved the expected volume. This method can be used in wells of 4265∼4921 ft depth and under high temperature more than 665°F.
This paper describes the completion and sand control methods for horizontal wells used in Shengli Oilfield with emphasis on the study and field application of the metal-fiber screen.
Practical and Robust Simulation for Anisotropic Reservoirs
Authors: Murakami Yuji , Namba Takao , Yamazaki Noboru 
Published: September 2010

AbstractSignificant areal heterogeneity and anisotropy are recognized in some fields, i.e. naturally fractured basement reservoirs in offshore South East Asia. In conventional Cartesian five point finite difference reservoir simulators, the coordinate system must coincide with the principal axes of permeability to eliminate tensor cross terms. As the simulators incorporating full tensor permeabilities are still not commercially available in the industry, a practical approach is necessary to represent complex and anisotropic reservoirs. In this paper, a modified grid scheme and interface permeability calculations are presented based on our in-house Voronoi-based flexible reservoir simulator (VERDI-3D). Numerical tests showed that the directional advances in pressure transients and water fronts can be represented by the proposed "pseudo-octagonal" grid system.
HSE Tools: Which Tools are Appropriate?
Authors: Hudson P. T. W. , van der Graaf G. C. , Parker D. , Lawton R. , Verschuur W. L. G. 
Published: September 2010

Abstract
A study into different HSE tools reveals why some tools may be better than others. Tools can be structured along two dimensions. One dimension loads on how much a tool is a managerial, long-term aid, providing information for improvement. The other dimension loads on the extent to which a tool is applicable at the workforce level, helping to manage immediate hazards and make current practices better. The appropriateness and acceptability of tools is also strongly determined by the company's safety culture and the national culture.
The analysis of why tools work found four crucial dimensions:
Proactive vs Reactive – Reactive tools are more appropriate in early stages, proactive tools are needed and effective only when the safety culture is sufficiently advanced. Hazard Recognition vs Hazard management – Some tools help people recognise the presence of their hazards, other tools help them to manage and prioritise. Behaviour vs Attitude – Early stages of safety culture require behaviour to lead attitude change; later stages are characterised by attitudes leading behaviour. Reward vs Punishment – Disciplinary methods have their place in abolishing specific bad practices, rewards help cultivate generally good practices but are easy to misapply.
Continuous striving for improvement creates a tension between how people think and feel about HSE and how they actually behave. This tension can be structured by the right tools to generate real improvement. Internal or mental models of what HSE management is about can only develop slowly. Proactive approaches rely on such models as positive attitudes become internalised.
Re-Development Issues and Challenges for a Very Old Oil Field, Masjed-I-Suleyman, South West Iran
Authors: Nguyen Hanh T. , Kelly Roy T. , Sodero Dario , Niakan Mohammad R. 
Published: September 2010

Abstract
This paper outlines the formulation of a re-development plan for the oldest producing field in the Middle East, Masjed-I-Suleyman, discovered in 1908 in the South West of the Islamic Republic of Iran and put into production in 1911. The field location is shown in Figure 1.
The difference between the volume and type of data acquired in 1908 versus that acquired now is in itself one of the greatest challenges to overcome when undertaking such a study. The field does not have a virgin reservoir fluid sample, nor early pressure measurements, or any measurement of produced gas volumes. However, these are key parameters which must be tested rigorously in the reservoir models.
The redevelopment plan revolves around a comprehensive reservoir study of the Asmari formation, a complex, fractured carbonate reservoir. The objectives of this study - the first on the field - are to gain a better understanding of the reservoir and its production and pressure performance over nearly a century and to develop a plan for further developing the field by drilling new vertical and horizontal wells. Reservoir characterization provides input data for a full field, dual porosity simulation model, which in turn verifies the input data. Complicated reservoir pressure and production history matches were successfully obtained to provide the basis for future production forecasts. Re-injection of gas and water to maintain reservoir pressure was also reviewed. Sensitivity studies on different locations for the new wells shows that a substantial incremental recovery can be recovered. Apart from the inherent geological complexity, the project faced tremendous data challenges such as the first field report having been written some 37 years after the start of production.
Estimating HIV Prevalence and Incidence in Africa from Mortality Data
Authors: Oster Emily 
Published: September 2010

Abstract
An estimated 33 million people are infected with the HIV virus, with 67% of them in Sub-Saharan Africa. Despite this, knowledge about HIV prevalence in Africa is limited and imperfect. Although population-based testing in recent years has provided reliable information about current prevalence in the general population, we have little reliable data on prevalence in early years of the epidemic. This paper suggests a new methodology for estimating HIV prevalence and incidence using inference from mortality data. This methodology can be used to generate prevalence estimates from early in the epidemic. This information is valuable for understanding how the epidemic has evolved over time and is also likely to be helpful in analyses that explore how policy affects the epidemic or how HIV affects other country-level outcomes.
Inflammation, Oxidative Stress, and Insulin Resistance in Polycystic Kidney Disease
Authors: Menon Vandana , Rudym Darya , Chandra Priya , Miskulin Dana , Perrone Ronald , Sarnak Mark 
Published: September 2010

Summary

Background and objectives
Most deaths in autosomal dominant polycystic kidney disease (ADPKD) are attributable to cardiovascular disease (CVD). We examined novel CVD biomarkers in different stages of ADPKD.

Design, setting, participants, & measurements
We recruited 50 hypertensive subjects with ADPKD with estimated GFR (eGFR) of >60 ml/min per 1.73 m2; 52 hypertensive subjects with ADPKD with eGFR of 25 to 60 ml/min per 1.73 m2; 42 normotensive subjects with ADPKD and eGFR of >60 ml/min per 1.73 m2; and 50 healthy controls. We assayed serum C-reactive protein and IL-6 as markers of inflammation; plasma 8-epi-prostaglandin F
2α (8-epi-PGF2α) and superoxide dismutase (SOD) as markers of oxidative stress; and homeostasis model assessment (HOMA) as a measure of insulin resistance.

Results
The hypertensive ADPKD eGFR of 25 to 60 group had higher levels of C-reactive protein and IL-6 than controls, normotensive ADPKD with eGFR of >60, and hypertensive ADPKD with eGFR of >60. The normotensive ADPKD eGFR >60, hypertensive ADPKD eGFR >60, and hypertensive ADPKD eGFR 25 to 60 groups had higher 8-epi-PGF2α and lower SOD than controls, with no difference between the ADPKD groups. There was no difference in HOMA levels between any of the groups. Adjustment for age, race, gender, and body mass index did not alter these relationships.

Conclusions
Inflammation and oxidative stress are evident early in ADPKD even with preserved kidney function. Inflammation exhibits a graded relationship with levels of kidney function, whereas oxidative stress demonstrates a threshold effect. These pathways may be therapeutic targets for CVD risk mitigation.
Spectral source parameters for weak local earthquakes in the Pannonian basin
Authors: Süle Bálint 
Published: September 2010

AbstractDynamic source parameters are estimated from P-wave displacement spectra for 18 local earthquakes (1.2 < ML < 3.7) that occurred in two seismically active regions of Hungary between 1995 and 2004. Although the geological setting of the two areas is quite different, their source parameters cannot be distinguished. The source dimensions range from 200 to 900 m, the seismic moment from 6.3x1011 to 3.48×1014 Nm, the stress drop from 0.13 to 6.86 bar, and the average displacement is less than 1 cm for all events. The scaling relationship between seismic moment and stress drop indicates a decrease in stress drop with decreasing seismic moment. A linear relationship of M w = 0.71 M L + 0.92 is obtained between local magnitude and moment magnitude.
Fluvial stacking due to plate collision and uplift during the Early Pleistocene in Cyprus
Authors: Schirmer Wolfgang , Weber Josef , Bachtadse Valerian , BouDagher-Fadel Marcelle , Heller Friedrich , Lehmkuhl Frank , Panayides Ioannis , Schirmer Ursula 
Published: September 2010

AbstractSouthern Cyprus is situated within a mosaic terrane that has been fragmented between the northward drifting African and Arabian plates and the Eurasian plate. Enormous uplift of the earth mantle in the Tróodos Mountains is explained by two models. The subduction model explains subduction along the Cyprean arc to be the driving force for uplift whereas after the restraining bend model westward squeezing of Cyprus along strike-slip faulting is responsible for the enormous uplift at restraining bends. Since its emergence as an island in early Miocene times, landscape formation on Cyprus has been strongly controlled by this uplift. Until the Plio-Pleistocene, a strait belt separated the southern unroofed ophiolitic core region-the Tróodos Mountains-from the folded Kyrenia range to the north. This former sea basin, nowadays the Mesaoría Basin, is linked with the Tróodos Mountains by a dissected glacis with a thick cover of river deposits. The highest and oldest river deposits (Apalós Formation) were studied in the Vlokkariá hill southwest of Lefkosía. The 45.5 m thick Apalós Formation of Early Pleistocene age exhibits 24 sedimentary units (Fluviatile Series). Their magnetostratigraphical characters align with the Matuyama chron including the Olduvai and Jaramillo subchrons thus comprising about 1.15 Ma within the Early Pleistocene. This fluvial stack indicates a very flat and deeply lying river environment flowing from a slowly uplifting Tróodos hinterland. It happened during the end of Early Pleistocene when the enhanced Tróodos uplift started the dissection of the stacked river plain.
Comparison between 3 infusion methods to measure cerebrospinal fluid outflow conductance
Authors: Sundström Nina , Andersson Kennet , Marmarou Anthony , Malm Jan , Eklund Anders 
Published: September 2010

Object
There are several infusion methods available to estimate the outflow conductance (Cout) or outflow resistance (Rout = 1/Cout) of the CSF system. It has been stated that for unknown reasons, the bolus infusion method estimates a higher Cout than steady-state infusion methods. The aim of this study was to compare different infusion methods for estimation of Cout.

Methods
The following 3 different infusion methods were used: the bolus infusion method (Cout bol); the constant flow infusion method, both static (Cout stat) and dynamic (Cout dyn) analyses; and the constant pressure infusion method (Cout cpi). Repeated investigations were performed on an experimental model with well-known characteristics, with and without physiological pressure variations (B-waves, breathing, and so on). All 3 methods were also performed in a randomized order during the same investigation in 20 patients with probable or possible idiopathic normal-pressure hydrocephalus; 6 of these patients had a shunt and 14 did not.

Results
Without the presence of physiological pressure variations, the concordance in the experimental model was good between all methods. When they were added, the repeatability was better for the steady-state methods and a significantly higher Cout was found with the bolus method in the region of clinically relevant Cout (p < 0.05). The visual fit for the bolus infusion was dependent on subjective assessment by the operator. This experimental finding was confirmed by the clinical results, where significant differences were found in the investigations in patients without shunts between Cout of the visual bolus method and Cout stat, Cout dyn, and Cout cpi (4.58, 4.18, and 6.12 μl/[second × kPa], respectively).

Conclusions
This study emphasized the necessity for standardization of Cout measurements. An experienced operator could partly compensate for difficulties in correctly estimating the pressure parameters for the bolus infusion method, but for the general user this study suggests a steady-state method for estimating Cout.
Minimally invasive application of a radial plate following placement of an ulnar rod in treating antebrachial fractures
Authors: Hulse D. A. , Kerwin S. C. , Saunders W. B. , Witsberger T. H. 
Published: September 2010

Summary
Objective: To describe a surgical technique for placement of a minimally invasive radial plate following application of an ulnar rod (MIPR) for treatment of antebrachial fractures.
Methods: Medical records (November 2005-June 2009) were searched to identify dogs with diaphyseal radius and ulna fractures stabilised by MIPR. Data retrieved included signalment, weight, limb affected, cause of injury, open versus closed fracture, number of fragments, implant size, number of screws used and cortices engaged, number of open screw holes, operative time, rod removal, complications and time to radio-graphic healing. To be included, dogs had to have evidence of radiographic healing during follow-up.
Results: Eight dogs with diaphyseal radius and ulna fractures treated with MIPR were included in the case series. All fractures were due to trauma and two fractures were open (grade 1). Rod loosening and osteomyelitis of the ulna occurred in one case which subsequently resolved with rod removal. Healing occurred in all cases with no implant failures. Median time to radiographic union was 10.5 weeks (mean ± SD = 17 ± 15 weeks range 4–52 weeks).
Clinical relevance: Use of MIPR constructs on diaphyseal fractures of the radius and ulna is an effective technique for managing these fractures using principles of biological osteo-synthesis. An intramedullary rod in the ulna assists with fracture reduction and stabilisation and rod removal is recommended once fracture healing has occurred.
Imaging studies of the hindlimbs of pacas (Cuniculus paca) bred in captivity
Authors: Rahal S. C. , Doiche D. P. , Machado M. R. F. , Vulcano L. C. , Teixeira C. R. , El-Warrak A. O. , Araújo F. A. P. 
Published: September 2010

Summary
Objective: To evaluate the hindlimbs of pacas bred in captivity using radiographic and computed tomography (CT) studies.
Animals: Nine mature pacas (Cuniculus paca) 5.9–8.2 kg in body weight.
Methods: Radiographical aspects of the bones of the hindlimbs were evaluated, and the Norberg angle and inclination angle were measured for each hindlimb. Anteversion angle were measured in CT examination.
Results: The bone anatomy of the hindlimb of the paca was similar to that of the guinea pig, apart from two lunulae and a single fabella (lateral) which were observed. The Norberg angle had mean value of 130.56º ±13.81 without any significant difference between testers. Inclination angles ranged from 142.44º ±4.82 to 145.44º ±4.09 by Hauptman’s method, and from 144.94º ±3.13 to 148.22º ±3.25 by Montavon’s method, for right and left hindlimbs respectively. Average values for the anteversion angles measured with CT ranged from 28.56º ±5.56 to 32.91º ± 2.62.
Clinical significance: The data may be used in future studies comparing the paca to other rodent species. In addition, the paca could be used as an animal model in orthopaedic research.
Non-steroidal anti-inflammatory drugs inhibit bone healing: A review
Authors: Barry S. 
Published: September 2010

SummaryThe ability of non-steroidal anti-inflammatory drugs (NSAID) to inhibit bone healing has been established in experimental animal models using mice, rats, and rabbits. The mechanism of action is largely unknown but stems from prostaglandin inhibition and is likely multifactorial. In human medicine NSAID are known to prevent heterotopic ossification, however the clinical importance of their effects on bone healing remains controversial. Although a small handful of reports suggest that NSAID suppress bone healing in dogs and horses, there is little published information to direct veterinary practice in domestic species.
Relation of the Norberg angle and position of the femoral head centre to the dorsal acetabular edge in evaluation of canine hip dysplasia
Authors: Skurková L. , Hluchý M. , Lacková M. , Mihalová M. , Ledecký V. 
Published: September 2010

SummaryCanine hip dysplasia (CHD) is a locomotive-system disease in dogs, which in many countries is the target of screening programs aimed at reducing the prevalence of CHD among descendants of predisposed dog breeds. Despite the efforts to apply genetic testing or ultrasound diagnostics in diagnosing CHD (as is common in human medicine), the main diagnostic process in veterinary medicine is by radiographic examination. The main two parameters which are used in diagnosing HD are the Norberg angle (NA) and the position of femoral head centre to the dorsal acetabular edge (FHC/DAE). We examined the relationship between these two parameters in the process of the determination of CHD degree by evaluating 225 randomly selected radiographs which were made during the period from 1993 to 2008. The aim of our study was to examine the validity of these two parameters in CHD classification as used in three different classification programs. Using Pearson’s correlation coefficient, the value of which was 0.85 (p <0.05), we observed a positive correlation. Comparing the three scoring systems for CHD evaluation, we found that the final degree of CHD was similar for 78% to 85% of cases using Flückiger’s scoring system versus a modified scoring system of 5 parameters without FHC/DAE. Results were significant.
The rationale behind novel bone grafting techniques in small animals
Authors: Griffon D. J. , Ragetly G. R. 
Published: September 2010

SummaryAutograft is considered ideal for grafting procedures, providing osteoinductive growth factors, osteogenic cells, and an osteoconductive scaffold. Limitations, however, exist regarding donor site morbidity and graft availability. Although allograft provides an osteoconductive matrix with some osteoinductivity, its availability is limited. To achieve optimal bone graft properties, researchers are developing new materials with the goal of designing synthetics as close to autograft as possible while still facilitating their clinical use. However, the constant evolution of internal fixation stimulates the search for growth factors and cells which could stimulate bone healing.