bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observations of Mergers between Squall Lines and Isolated Supercell Thunderstorms
Authors: French Adam J. , Parker Matthew D. 
Published: January 2012

Abstract
A set of 21 cases in which an isolated supercell merged with a squall line were identified and investigated using analyses from the Rapid Update Cycle (RUC) model, archived data from the Weather Surveillance Radar-1988 Doppler (WSR-88D) network, and severe storm reports. This analysis revealed two primary environments associated with these mergers: a weak synoptic forcing, weak to moderate shear environment (WF) and a strong synoptic forcing, strong shear environment (SF). These environments bear a strong resemblance to those identified for progressive (WF) and serial (SF) derechoes in past studies. Radar reflectivity data revealed a spectrum of storm evolution patterns that generally lead to the merged system organizing as a bow echo. At one extreme, observed exclusively in the WF environment, the entire squall line evolved into a large bow echo following the merger. At the other extreme, observed for several cases in the SF environment, a localized bowing segment developed embedded within the larger squall line. The remaining cases exhibited characteristics best described as a hybrid of these extremes. Storm rotation generally weakened and became concentrated in low levels following the merger, although the exact evolution differed between the two background environments. Finally, an analysis of storm reports revealed that hail reports were maximized premerger and severe wind reports postmerger in both environments, while the distribution of tornado reports varied. In the WF environment a larger fraction of tornado reports occurred postmerger, while tornado production was maximized premerger in the SF environment. This suggests an evolving severe weather threat during the course of the merger, the details of which depend on the background environment.
Synthetic Satellite Imagery for Real-Time High-Resolution Model Evaluation
Authors: Bikos Dan , Lindsey Daniel T. , Otkin Jason , Sieglaff Justin , Grasso Louie , Siewert Chris , Correia James , Coniglio Michael , Rabin Robert , Kain John S. , Dembek Scott 
Published: January 2012

Abstract
Output from a real-time high-resolution numerical model is used to generate synthetic infrared satellite imagery. It is shown that this imagery helps to characterize model-simulated large-scale precursors to the formation of deep-convective storms as well as the subsequent development of storm systems. A strategy for using this imagery in the forecasting of severe convective weather is presented. This strategy involves comparing model-simulated precursors to their observed counterparts to help anticipate model errors in the timing and location of storm formation, while using the simulated storm evolution as guidance.
Corporate Social Responsibility and Strategy
Authors: Gupta Ananda Das 
Published: January 2012

Corporate social responsibility (CSR) and corporate sustainability represent the way companies achieve enhanced ethical standards and a balance of economic, environmental and social imperatives addressing the concerns and expectations of their stakeholders. Corporate governance reflects the way companies address legal responsibilities, and therefore provides the foundations upon which CSR and corporate sustainability practices can be built to enhance responsible business operations. Operational uncertainties and difficulties are compounded by recent observations of ‘company anxiety’ regarding CSR communications. Over-promising or declarations of rightness and good intentions could cause the mistrust of consumers and stakeholders, creating the opposite effects from those expected. Companies are recognizing that corporate responsibility communications should be low tone and straightforward, reflected in the actual behaviour of every member of the company, which is extremely difficult to achieve before CSR is integrated into the company’s bloodstream.
The Use of a Single-Level Construct Model to Evaluate Nonmetallic “Flexible” Rods
Authors: de la Borbolla Ian Rubín , Prevost Julien , Scifert Christopher , Turner Joe 
Published: January 2012

Abstract
The current ASTM F1717 standard specifies the static and fatigue testing conditions for extradiscal spinal implant assemblies. For the lumbar region, the standard stipulates a vertebrectomy model for said tests. While this testing setup has proven effective in analyzing overall construct stiffness, yield load, and displacement for rigid constructs, there is a growing segment of products and cases which amendments to the standard might better represent. One opportunity to evolve the current standard is in integrating test parameters which address the greater flexibility of semirigid or flexible systems such as those made from polymeric or metallic-polymeric materials. Since these rods are considerably more flexible when compared to rigid metallic rods, they create unique testing challenges. In addition, the current standard lacks a specification for testing single-level constructs. Considering that the overall dynamics of single-level cases vary greatly from the current vertebrectomy model, a modification or creation of a standard is needed. For the two reasons presented above, a single-level “discectomy” model has been developed to consider these unique testing conditions.
Photoactivity tests of TiO2 and ZnO sunscreen ingredients
Authors: Lewicka Zuzanna. A. , Colvin Vicki. L. 
Published: January 2012

ABSTRACTNanosized titanium dioxide (TiO2) and zinc oxide (ZnO) are widely used as inorganic sunscreen pigments. However, these metal oxide particles may also be photocatalytic and generate DNA-damaging reactive oxygen species. Therefore, we evaluated the photochemical properties of the whole sunscreen emulsions that contained nanoscale components and the inorganic particles derived from these sunscreens using several assays such as dichlorofluorescein fluorescence, the decolorization of Congo red dye and DMPO spin trap electron paramagnetic resonant spectroscopy. The results of these three tests showed that samples with ZnO nanoscale materials were more photoactive than the samples that contained TiO2 nanoparticles.
Effects of VTI Anisotropy on Shale Reservoir Characterization
Authors: Banik Niranjan , Egan Mark 
Published: January 2012

AbstractPresently shale reservoirs are the one of the hottest plays in the oil industry. Our understanding of these reservoirs rapidly progressed from one of a continuous type, to that of a spatially varying type. Two key elastic parameters, Young’s modulus and Poisson’s ratio are critically relied upon, to seismically high-grade these spatially varying reservoirs in terms of their reservoir and completion qualities. Isotropic elastic properties are assumed in the delineation of ‘frac’able’ zones and sweet spots. However, these shale formations are highly anisotropic even in the absence of any in-situ fractures and there are multiple Young’s moduli and Poisson’s ratios in an anisotropic medium.In this paper we discuss the effects of vertical transverse isotropy (VTI) in characterizing shale reservoirs in terms of Young’s moduli and Poisson’s ratios. We begin by rewriting Young’s modulus and Poisson’s ratio formulae in terms of Thomsen’s anisotropy parameters (Thomsen,1986). Both approximate and exact expressions are given. Approximate relations in terms of anisotropy parameters are easier to interpret than those in terms of the stiffness coefficients. We then discuss the results in terms of relevant ranges of values of these anisotropy parameters. Also, an important contribution to fracture initiation and containment comes from the uniaxial stress ratio (Higgins et al., 2008;Sayers, 2010, Iverson, 1995). It is the ratio of the horizontal to the vertical stresses in the absence of any transverse strain. The effects of anisotropy on the uniaxial stress ratio are discussed in this context. Finally we discuss how P-wave surface seismic data can be integrated with borehole and other measurements to estimate relevant elastic attributes in these highly anisotropic shale formations.
New Hydraulic-Fracturing Process Enables a Low-Risk, Operationally Efficient Solution While Maximizing Stimulation Effectiveness in Unconventional Reservoirs
Authors: Beaman Daniel , McNeil Fraser 
Published: January 2012

Abstract
Technological advances and improved operational efficiency have made unconventional resources around the globe far more lucrative for producers. The challenge in recovering hydrocarbons from unconventional resources is low permeability, making it essential that a cost-efficient fracture-stimulation treatment program be performed. However, while the wells being completed are economical, are operators truly capitalizing on their full potential?
The process of fracturing unconventional reservoirs has remained virtually unchanged in recent years. Stimulation treatments are pumped at high rates through multiple perforation clusters over a large interval and isolated using mechanical plugs. This poses several problems: Uncertainty of the number of fractures created.Uncertainty of proppant placement into fractures.Costly and time-consuming recovery from screenouts.Pumping plugs results in overflushing the near-wellbore.Treatment changes cannot be seen at the perforations until a casing volume is pumped.Increased cost, footprint, personnel, and hydraulic-horsepower (HHP) requirements.
This paper presents a high-rate coiled tubing (CT) fracturing technique that enables customized fracture treatments to help maximize stimulated reservoir volume (SRV) by manipulating flow rate and proppant concentration at the perforations in response to reservoir pressure. Therefore, every gallon of fluid and every pound of proppant can be used to effectively stimulate the formation. Recovery from screenouts is fast because of having coil in-hole, but the functionality of the process enables screenouts to be avoided all together. At the end of the treatment, the well is simply cleaned out, and the entire operation is completed with only one trip in hole and with no plugs to be drilled out. These benefits combined can maximize return on investment for the operator. This paper includes a side-by-side comparison of this technique with a conventional fracturing treatment, weighing risk, stimulation effectiveness, operational efficiencies, and cost savings.
Effect of Sand Lens Size and Hydraulic Fractures Orientation on Tight Gas Reservoirs Ultimate Recovery
Authors: Kantanong Narisara , Bahrami Hassan , Rezaee Reza , Hossain Mofazzal , Nasiri Amir 
Published: January 2012

Abstract
Low permeability and complexities of rock formation in tight gas resources make it more complicated to predict well production performance and estimate gas recovery. To produce from the unconventional resources in the case that formation rock is not sensitive to damage caused by liquid invasion, hydraulic fracturing is the most common stimulation treatment to improve the production to the excepted economically rate.
In term of reservoir geometry, tight sand formations are normally stacks of isolated lenses of sand bodies that are separated by shale layers. Each sand lens varies in shape and size and acts as a trap for original hydrocarbon accumulations. The sand lenses parameters such as length and width can play important role in controlling gas recovery from hydraulically fractured tight gas reservoirs.
This study shows the effect of drainage pattern of the lenticular sand bodies on production performance and ultimate gas recovery in tight gas formations. Analytical and numerical simulation approaches are used in order to understand the effect of hydraulic fracture parameters and also attribution of sand lens size and shape to the drainage pattern and gas recovery in hydraulically fractured tight sand gas reservoirs.
The results highlighted that in tight gas with massive hydraulic fractures, sand lens size in the direction perpendicular to hydraulic fracture wings has the major impact on gas recovery. Sand lens size in the direction parallel to hydraulic fracture wings does not have significant effect on gas recovery. When the sand lenses are isolated and small in size, from a singlewell-enhancement perspective, the gas recovery will increase significantly by performing massive hydraulic fracturing through isolated lenses.
Pinpoint-Fracturing Technology Improves Efficiencies While Solving Issues with Conventional Hydraulic-Fracturing Processes
Authors: Chellani Divesh , Gurnito Nuratas , Ables Colt 
Published: January 2012

Abstract
This paper discusses issues encountered by an operating company in West Bengal, India and how technological, operational, and engineering solutions were applied to resolve them. The goal was to complete a well with only one coiled tubing (CT) trip while placing several pinpoint hydraulic fractures, thus increasing efficiency. The solution entailed using hydrajet perforating combined with annular pumping and proppant plugs for diversion.
The Recent Applications of Jet Pump Technology to Enhance Production from Tight Oil and Gas Fields
Authors: Sarshar Sacha 
Published: January 2012

Abstract
Production from many oil and gas fields becomes restricted as the reservoir pressure drops. The situation becomes worse for fragmented reservoirs and tight reservoirs, when water-cut also increases. In order to maintain production at an economical rate, and also to increase total recovery from the field, a production boosting system is always required.
Jet pumps are simple passive devices which use a high pressure (HP) fluid as the motive flow to boost the pressure of produced gas and liquid phases. For producing wells; it enables the flowing wellhead pressure (FWHP) to be reduced in order to increase production, whilst meeting the downstream production pressure requirements. The applications include also revival of the liquid loaded wells.
In recent years the industry has become more aware of their applications and benefits. This paper covers their applications, including; boosting production from selected oil and gas wells, boosting the pressure of low pressure gas, prevent flaring very low pressure gas, eliminate the need for intermediate compressors, de-bottlenecking compressors, prevent HP wells backing out LP wells, and revival of liquid loaded wells. In addition to referring to recent field examples, issues such as performance, ranges of operation, key features of the system and solutions for gas or oil production applications are described. Key operation issues are also addressed.
The paper addresses the economic aspects shown by typical pay-back periods for recovery of the capital from the benefits gained such as added revenue.
Quantifying the Role of Hematite Cement in Controlling Permeability in a Deep Tight Gas Reservoir from the North Sea
Authors: Ali Arfan , Abdalh Salem , Potter David K. 
Published: January 2012

Abstract
Recent work has shown the potential usefulness of magnetic susceptibility and hysteresis techniques in assessing the impact of fine grained hematite on permeability in red and white sandstone samples (Potter et al. 2009; Ali and Potter, 2011b). The present study demonstrates that hematite cementation is a major controlling factor on permeability in a deep tight gas reservoir in the North Sea. Magnetic susceptibility measurements undertaken on core plugs in this reservoir showed a strong correlation with probe permeability performed on the same plug samples. Moreover, samples with a higher content of hematite exhibited lower permeability values. Thin section analysis revealed the presence of a thin (approximately 10-15µm) rim of hematite cement surrounding quartz grains, which block pore connections and reduce permeability.
Magnetic hysteresis measurements on some representative samples indicated a very similar paramagnetic clay content in both the low and high permeability samples suggesting that the clay (mainly illite) is not the dominant controlling factor producing the variations in permeability that we observed. Since samples with higher hematite content exhibit lower permeability it appears that hematite is a major control on the permeability variations seen in this reservoir. Whilst the paramagnetic clays undoubtedly have an influence on the absolute permeability value, since increasing paramagnetic clay content has previously been shown to correlated with decreasing permeability (Potter, 2007), small amounts of hematite cement can significantly further reduce the permeability. Analysis of the magnetic hysteresis parameters on a Day plot indicated that the permeability was essentially independent of the hematite particle size for the fine particle sizes observed in this study.
An Effective Approach to Unconventional Resource Exploration in the Middle East
Authors: Bouhlel Aziza Moumen , Bryant Ian 
Published: January 2012

Abstract
In the last decade, shale resource exploitation has transformed North American production capacity through technological improvements in horizontal drilling and the ability to efficiently stimulate horizontal wellbores using multiple hydraulic fractures. The 2011 U.S. Energy Information Administration estimates there are unproved, technically recoverable shale gas resources of 827 Tcf (in addition to 20.1 Tcf of reserves) in the USA alone. Exploration and exploitation of Middle East organic-rich shales are just beginning, and discovery of economically viable resources requires a concerted effort. While Middle East resources in place could be much greater than those in North America, "sweet spots" need to be found in which established source rocks can also function as reservoirs. Evaluating these opportunities requires refined reservoir characterization workflows rather than the statistical approach that characterized early development of North American shale plays, which benefited from high gas prices, numerous existing wells, and infrastructure to support drilling and fracturing. With lower well density and higher well costs than in North America, successful exploration for unconventional hydrocarbon resources in the Middle East will necessarily rely more on modeling.
A petroleum systems–oriented approach defines sweet spots by predicting reservoir quality and potential completion quality. Using proven and effective tools, sweet spots are identified early in the life of unconventional plays. Since reliable, comprehensive data concerning the behavior of shale resource systems under varying conditions are not widely available in the Middle East, petroleum systems modeling would yield key risk and value information.
Standard petroleum systems modeling tools have recently been improved, providing more accurate results based on experience of modeling unconventional plays. By extending traditional basin and petroleum systems modeling with sophisticated adsorption functionality, the modeling of hydrocarbon adsorption on kerogen and primary migration within tight source rocks has been significantly enhanced. These methods have the potential to improve the efficiency and effectiveness of Middle East shale resource evaluation.
Design, Application, and Implementation of Well Intervention Services within a Deep HP/HT Tight Gas Exploration and Appraisal Project
Authors: Curtino Joe , Ouaguennouni Mourad , Judd Tobias , Al Habsi Ali 
Published: January 2012

Abstract
The appraisal of deep tight gas reservoirs can be technically and economically challenging, with success dependent on applying the most efficient completion technology. Inevitably, this includes designing well completions that encompass the deployment of multiple hydraulic fracturing treatments. There is a tendency in the completion design phase to under-assess the number and variety of interventions that a well could undergo during its evaluation. Subsequently, the development and application of the appropriate well intervention strategy is crucial in maximizing the well potential and reservoir understanding. The deliverable of any tight gas appraisal program is to increase the level of confidence in continuing to pursue the resource opportunity by demonstrating stable and sustainable gas inflow flow rates.
Recent drilling success targeting deep frontier gas reservoirs, such as the Amin located in the central part of Oman, have resulted in the need to evolve the well intervention process to include several new (for the region) technologies. These included the deployment of abrasive perforating to facilitate the initial formation breakdown operations, milling out the shoe track for a hydraulic fracturing treatment in an openhole setting, restoring full wellbore access by milling out multiple frac plugs, and temporary installation of a velocity string to eliminate liquid loading issues. Historically, many of these individual processes have been attempted or deployed with varying levels of success, but this is the first time that they have been integrated into a well strategy.
This paper summarizes the process of selecting the best options for well intervention operations in low-permeability gas reservoirs. The integrated work design consideration and results of these completion techniques will be presented along with the key learnings derived from the process.
Potential Unconventional Gas Supplies in Bangladesh
Authors: Bishop Michele , Cronshaw Mark , Lencioni Letha , Rensberger Shannon 
Published: January 2012

Abstract
There is the possibility of discovering and developing coal bed methane (CBM) and shale gas in Bangladesh; however the amounts of gas and the timing of exploration and development are uncertain. It is common to use probabilistic methods to determine the range of possible unconventional resources as well as the associated probabilities and reserve/resource categorization. Such probabilistic methods can be extended to consider the exploration and development timing as well as the amount of resources. We have prepared such a country-wide model for Bangladesh that considers gas supply from existing fields, known prospects and leads, unmapped resources, CBM, and shale gas.
The model results demonstrate possible outcomes for three time horizons: short term (next 5 years), intermediate term (5-10 years), and long term (beyond 10 years). The short term gas supply is dominated by supplies from existing fields. Gas availability in the intermediate and long terms is strongly influenced by possible new discoveries including unconventional gas. The model predicts the probability of sufficient gas supplies to meet demand, and also the possibility of gas supplies in excess of demand. The results are useful for planning concerning (a) gas imports and/or use of other energy types, and (b) the potential need for gas exports or the curtailment of gas production in the event of very substantial gas discoveries. The model also demonstrates the potential benefit associated with acceleration of exploration and development activities.
The probabilistic framework naturally results in a range of scenarios. Such a framework with multiple scenarios and associated probabilities allows for a more informed debate about country-wide energy planning.
Wattenberg Field Unconventional Reservoir Case Study
Authors: Moritz Edwin C. , Barron Natalie 
Published: January 2012

AbstractThe Wattenberg Field located in the Denver Basin of Colorado USA has been explored and developed since the 1970s. The field contains large reserves of primarily gas and some condensate in unconventional tight sand and shale reservoirs. Over time, technologies have emerged to efficiently exploit the hydrocarbon resources in this field and this includes hydraulic fracture techniques, down spacing and identification of sweet spots. This presentation summarizes the development of the techniques used to exploit these unconventional reservoirs and such techniques can be used for future exploration and development of other unconventional reservoirs globally.