bluuebunny/crossref_metadata_2025 huggingface dataset:
Unconventional Natural Gas Potential in Saudi Arabia
Authors: Sahin Ali
Published: December 2013

Surge in the worldwide demand for natural gas, in recent years, has resulted in a considerable interest in the unconventional natural gas resources in many countries, including Saudi Arabia. Numerous studies indicate that the supply and demand balance can be achieved through the exploitation of unconventional resources which are located in the major hydrocarbon basins of the world. The scope of this paper is to review the main sources of unconventional natural gas with some emphasis on potential resources in the Arabian Peninsula, and to present initial results derived from a recent study of Paleozoic formations in the Rub’ Al-Khali Basin.

Besides contributing to the general knowledge on unconventional natural gas resources, the information provided in this paper is expected to guide current exploration activities on the unconventional natural gas in Paleozoic formations in the Rub’ Al-Khali Basin.

Based on the lognormal model, it has been demonstrated that the volume of unconventional gas resources in a particular basin is several times that of the proved reserves in that basin. Considering this model, it is possible to deduce that vast amounts of unconventional resources exist in the Arabian Peninsula. Potential targets have been identified to be the Paleozoic formations, including Qasim, Sarah, Qalibah, Jauf, Unayzah, and Khuff. Average porosity and permeability measurements, based on the combined data from several vertical wells intersecting each formation in the Rub’ Al-Khali Basin, have been compared with the corresponding published data from the producing tight gas formations from North American basins. Porosity and permeability values, representing various formations in the Rub’ Al-Khali Basin, compare well with the corresponding parameters from North American basins. The same data, also, revealed the differences and similarities of patterns of distributions of petrophysical parameters in formations under consideration.

Major technical contributions of this paper include: (1) appraisal of distribution of unconventional natural gas resources in the Arabian Peninsula, (2) characterization of natural gas potential of various formations, and (3) comparison of petrophysical parameters with the corresponding values from similar basins from North America.
Filling the Experience gap in the Drilling Optimization Continuous Improvement Cycle through a Self-Learning Expert System
Authors: Kirby Cliff , Sadlier Andreas , Wood Christopher , Vinther Morten
Published: December 2013

With deeper and more complex wells being drilled every year to gain access to reserves, experience and knowledge are the keys for minimizing associated risks and reducing costly non-productive time.

Over the last decade, drilling optimization processes and practices have delivered substantial drilling improvements in many different environments worldwide. This has been based on a continuous improvement cycle, consisting of four distinct phases: planning, execution, post-well analysis and lessons learned, which essentially yields personnel experience and knowledge.

Given the current demographics in the oil industry, which is heavily biased towards the 50+ years of age, the "big crew change" is just around the corner. As more and more graduate engineers enter the industry the resulting experience gap needs to be bridged.

Within the controlled environment of the office, graduate engineers are offered guidance and support during the planning phase, however real-time execution requires timely specialist advice and guidance to mitigate drilling hazards. Drilling hazards provide tell-tale signs, and if these signs are captured early, corrective actions can be taken to reduce or completely avoid their impact, reducing operational risk and well delivery costs.

This paper describes an expert system that has been developed to offer immediate guidance to support the delivery of specific real-time specialist advice – based on the system’s self-learning of previous drilling events. The expert system monitors real-time drilling parameters and uses case-based reasoning (CBR) to recognize and capture current incidents that are similar to those that have occurred in the past.

The system can be used to prevent drilling problems before they occur with real-time case-based reasoning for enhanced risk assessment and hazard mitigation. The paper will review examples of packoffs, stuck pipe and lost circulation that have been mitigated.
Produced Water Re-Injection System Optimization: Recipe to Improve Efficiency
Authors: AlKhalifa Hani H.
Published: December 2013

This paper wills discuss in details a technique to improve electric power efficiency of produced water re-injection. Typically such systems are designed with some reservoir performance uncertainties, production demand changes and fluctuation in instantenious flow to through the system. This fact encourages designers and operators to oversize the system to be in the safe side. However, this approach comes on the expense of efficiency of the system (20–30%).

The paper evaluates the existing water disposal system within Upstream Production Facilities at the Ghawar Field in terms of capacity and operations cost and define the required upgrades and areas of optimization. All evaluated plants are conventional Gas Oil Separation Plants where produced water is gravity separated, treated and re-injected back into the producing formation.

The paper will show a step by stem approach to effectively analyze produced water disposal systems and evaluate alternatives to significantly improve their efficiencies and guarantees adequacy. This approach evaluates the whole system from the suction of the disposal pumps to the bottom of the disposal wells of multiple facilities simultaneously. The methodology address reservoir pressure, headers and laterals, pumps configuration and drive mechanism in details. This approach addresses both short and long term optimization needs. In this study the outcome was substantial. Proposed modifications once applied will result into debottlenecking system capacity and improves efficiency to 60–70%. The conserved power was more than 100 giga watts and millions of dollars annually.
The Effect of Noise Attenuation on Data Driven Interpreter Guided Fault Analysis
Authors: Lee Owen , Elghorori Ahmed , Bissett Adrien
Published: December 2013

Prior to any structural attribute analysis on 3D seismic data it is usually necessary to undertake noise cancellation to remove the noise and enhance data quality. We present the results of applying noise cancellation techniques to 3D seismic data and show how that can improve our imaging and analysis of faults. Furthermore we look at automated methods for improving the mapping of major and minor faults using a unique fault workflow.

To be effective volumetric noise cancellation must attenuate noise whilst minimizing the loss of information in order to maintain what is genuine geology. To do this we systematically apply edge preserving methods for attenuating both random noise and high spatial frequency coherent noise that may be masking our true representation of faults. Seismic attributes such as Semblance can then be applied to identify discontinuities within the data which may correlate to structural faults. These types of discontinuity attributes are very sensitive to noise in the data, so running the algorithms on noise attenuated data can have a significant impact on the quality of the result and the scale of the faults that can be interpreted.

Structurally oriented and adaptive filters significantly enhance the reflector continuity and improve lateral and vertical imaging of faults by attenuating higher frequency noise whilst preserving edges.

We will present examples of the effect of noise cancellation on the complete fault workflow from initial attribute analysis to semi-automated fault extraction and analysis, and show the improvements in the fault interpretation with the application of noise attenuation.
Mitigation of Sweet Gas Corrosion in Gas Gathering Systems
Authors: Al-Harbi Mamdouh E.
Published: December 2013

Sweet Gas Corrosion, or CO2 corrosion, is one of the main corrosion mechanisms in oil and gas industry. It results from presence of water containing dissolved carbon dioxide CO2. This phenomenon is influenced by the partial pressure of carbon dioxide, temperature, flow regime and water content.

Over the past few years, concern has grown for sweet gas corrosion in some Saudi Aramco Gas gathering facilities. Severe localized corrosion was noticed in some gas wells piping.

The metallurgy used for surface gas piping is seamless carbon steel in production line spools, flow lines and trunk lines. Corrosion resistant alloy (CRA) is used for the valves to prevent corrosion in the body cavity.

Investigation studies and piping UT surveys were conducted at different areas to assess the severity and extent of such phenomena. Turbulent flow was found to be the major factor for severe sweet gas corrosion in first two spools downstream of wellhead wing valve as well as in spools upstream & downstream of choke valve. Furthermore, insufficient dosage rate of corrosion inhibitor contributed to high metal loss in downstream section of the choke valve in some wells.
Sequence Stratigraphic Modeling Using Outcrop Data in 3D Space
Authors: Sen Gargi
Published: December 2013

Introduction and objective of work

Sequence stratigraphy has grown itself as an extremely useful tip for prediction of lithology and basin architecture in both clastic and carbonate settings. This concept is mostly applied in the Petroleum industries for reservoir prediction using an integrated approach that comprises analysis of seismic, well, outcrop, palaeontological and any other relevant data available. Petrel is widely accepted application hitherto being used for interpretation and reservoir modeling using well and seismic data.

The current work has been carried out with an attempt to demonstrate the use of outcrop data for interpretation of different sequence stratigraphic parameters and subsequently to build a three-dimensional depositional model in Petrel.
The Impact of an Infrastructure Reliability and Data Communication Index on Improving Intelligent Field Operations in an Oilfield in Saudi Arabia
Authors: Velarde S. A. , Al-Ghamdi A. A.
Published: December 2013

Intelligent Field upstream operations in the Oil & Gas industry encompass infrastructure that provides real-time data for monitoring and enabling informed and efficient decision-making leading to improved field operations. Therefore, it is vital to ensure that the infrastructure is reliable and that the data obtained is managed properly to make it available to end users. This paper proposes an integral approach to measure Intelligent Field Infrastructure (IFI) and data communications reliability and explains its applications and reachability on field performance.

This innovative method supports engineers to tackle issues in timely manner. In addition, a robust IFI optimizes production strategy by exploiting available data to improve well rate compliance, monitor well integrity and reduce field surveillance activities. Furthermore, a reliability index requires a consistent asset inventory supported by an effective maintenance strategy that is perceptible to all involved organizations.

Six sigma methodology tools are to be implemented to address reliability. To conduct a root-cause analysis leads to identify the flaws in data communications and infrastructure. Then, data is to be compiled within a process mapping structure that can be used to generate performance plots ranked upon Failure Mode and Effect Analysis (FMEA). Building a reliability index powered by visualization tools lead to expose hidden areas of opportunities to improved field operations. This integrative approach provides different organizations with one platform to overcome reliability issues and reduce equipment downtime; hence, maintaining asset value and capitalizing its capability.

The approach presented in this study is relevant to Oil & Gas industry professionals involved in IFI for understanding the impact of asset integrity on remote operations capability. It also sheds light on understanding the role of information-driven analytics on optimizing field performance.
Vertical Cased Producers Outperform Horizontal Wells in a Complex Naturally Fractured Low Permeability Reservoir
Authors: Widjaja Danang R. , Lyngra Stig , Al-Ajmi Fahad A. , Al-Otaibi Uthman F. , Alhuthali Ahmed H.
Published: December 2013

This paper is a case study for a complex highly fractured low matrix permeability reservoir. The material presented demonstrates that understanding the fracture influence on reservoir fluid flow is essential for successful development and reservoir management of this type of naturally fractured reservoir. Several well examples are offered illustrating the paramount importance of completion strategy with increased reservoir maturity to enhance matrix oil recovery and minimize natural fracture network water production.

The case study reservoir was initially developed with a small number of vertical cased, perforated and stimulated producers produced at a restricted total off take rate and pressure supported by peripheral water injection. The next development phase was the drilling of single lateral horizontal producers completed open hole with approximately 1 km of reservoir contact. In earlier stages of production, both vertical and horizontal well completion types performed well as the natural fractures were oil filled.

As water moved towards a structurally higher position due to natural fracture system depletion, the open hole completions became a major water production source. Subsequently, a revision of the well completion strategy was required to minimize the water encroachment through the fracture system with the intent to maximize matrix oil recovery and also resolve well lifting problems. This paper presents the production performance review that followed after recompletion of the existing open horizontal wells with perforated liners or special equipment, such as stage stimulation completions.

The production performance data from the recompleted horizontal wells are compared to well production performance of the original and some newly drilled cased, perforated and stimulated vertical producers. In this case, it is apparent that simplicity wins and the vertical well solution is the optimum well strategy for future development.
Application of Fast-SAGD in Naturally Fractured Heavy Oil Reservoirs: a Case Study
Authors: Sarapardeh A. Hemmati , Kiasari H. Hashemi , Alizadeh N. , Mighani S. , Kamari A.
Published: December 2013

Steam injection process has been considered for a long time as an effective method to exploit heavy oil resources. Over the last decades, Steam Assisted Gravity Drainage (SAGD) has been proved as one of the best steam injection methods for recovery of unconventional oil resources. Recently, Fast-SAGD, a modification of the SAGD process, makes use of additional single horizontal wells alongside the SAGD well pair to expand the steam chamber laterally. This method uses fewer wells and reduces the operational cost compared to a SAGD operation requiring paired parallel wells one above the other. The efficiency of this new method in naturally fractured reservoir is not well understood. Furthermore, how operational parameters could affect the efficiency of this method is a topic of debate. In this study, Fast-SAGD is compared through numerical reservoir simulations with standard SAGD in an Iranian naturally fractured heavy oil reservoir and additionally some operational parameters including initiating time of steam injection in offset well, number of cycles assuming the same total period of steam injection, offset injection pressure, elevation of offset well from the bottom of reservoir and vertical distance of production and injection SAGD well pairs have been evaluated in Fast-SAGD process. The operational parameters have been optimized based on Recovery Factor (RF) and economical points. The results of this study demonstrated the exceptional performance of Fast-SAGD process in naturally fractured reservoirs and the RFand thermal efficiency of Fast SAGD are enhanced tremendously comparsed to SAGD. In addition, the results indicated that the most important parameters that should be optimized before Fast-SAGD is initiating time of steam injection in offset wells. This study reveals improved efficiency and lower extracting costs for heavy oil in naturally fractured reservoirs applying Fast-SAGD process. Also it is indicated that optimization of operational parameters significantly improves Fast-SAGD performance in such reservoirs.
Reservoir Quality Impact on Identifying Unayzah Prospective Areas in Abu Dhabi
Authors: Al-Zaabi Mohamed R. , Taher Ahmed A.
Published: December 2013

Reservoir quality in the Unayzah is largely controlled by depositional environment early clay diagenesis, burial- compaction and quartz cementation. Present day reservoir quality can be predicted by modeling the porosity evolution of simplified model rocks with representative depositional and early diagenetic attributes through their burial history.

In Abu Dhabi Unayzah fluvial sands are predicted to have consistently low reservoir quality due to poorly-developed, early grain coats that have allowed abundant quartz cement to form. In the Unayzah C, open fractures observed in fluvial samples may provide useful high permeability streaks within these intervals. Fluvial sands are predicted to have higher porosities in areas with low thermal maturity, where quartz cementation would be less advanced.

Unayzah sandy sabkha reservoir quality is predicted to be uniformly poor as a result of fine grain size, poor sorting, and early diagenetic clays that filled pores. Unayzah Aeolian sand quality is variable, depending on the type of clays in pores. A zone of infiltrated clay coats is observed in well H-1. this zone is characterized by clean, effective macroporosity, resulting in good permeabilities and low connate water saturations. Below this zone, all Unayzah aeolian sands contain diagenetic clays. Where finer grain size or poorer sorting results in small pores, the diagenetic clays bridge much of the porosity and significantly reduce effective macroporosity. However, in well-sorted, coarser-grained dune sands, pores are large enough to be lined but not filled with diagenetic clays.

Reservoir quality prediction approach is based on conceptual model of sandstone porosity evolution, with burial derived from observation in multiple reservoirs. In this model, the main controls on the pore system evolution are mechanical compaction and cementation.
Terrestrial Wireless Broadband Enables Smart Drilling
Authors: Al-Lawati Ali
Published: December 2013

This is a presentation on how wireless communications can enable smart drilling in the oilfield, and the benefits that oil and gas companies can realize from smart drilling procedures enabled by wireless communications.

The concept of the digital oilfield is an oilfield that is connected from end to end. It’s an oilfield where all devices, all people, and all assets are tracked, monitored, and can participate in a joint collaboration that is the operation.

These benefits can only be realized with a ubiquitous network that covers the oilfield from end to end, and enables last mile connectivity for activities like wellhead automation, level field connectivity, operational video surveillance, micro seismic applications, asset tracking via RF-ID and Wi-Fi-RD, energy management, collaborative working environment, and all the collaboration tools that this entails, and, of course, smart drilling. The location, geography and distances associated with most oil fields require that the network be wireless, and new advances in wireless technology have now made this vision real and affordable.

We’re going to look specifically at smart drilling, the benefits that smart drilling brings to the operation as a whole and how wireless communications is especially well positioned to enable smart drilling in today’s enhanced oil recovery oil and gas operation.

The promise of enhanced oil recovery can be realized when new techniques and new technologies allow us to recover oil that in the past we were have been unable to extract. With enhanced oil recovery, additional extraction is possible, safely and quickly.
Framework Model Building in Highly Complex Structures Utilizing Multi-Azimuth 3D Seismic Data: Case History from Bahrain Field
Authors: Maili Eduard , Hoffman David , Al-Tawash Feras
Published: December 2013

The workflow discussed in this paper shows the process of building a complex fault framework using wide-azimuth seismic and abundant well data. 3D fault interpretation using azimuthal seismic volumes allows for subtle fault detection and better fault definition. Using special workflows which "snap" seismic faults to the well fault cuts, we illustrate how to build, and quickly update a very complex structure framework with a high level of accuracy.

The Bahrain field is a salt-cored, elongated and almost N-S anticline, with multiple oil and gas reservoirs in formations of Paleozoic, Jurassic, and Cretaceous age. Structural deformation has been nearly continuous from Triassic to early Tertiary, with a complex growth and deformation history (Samahiji and Chaube, SPE 1987), resulting in a highly-faulted structure with compartmentalized and fractured reservoirs. Therefore, building an adequate structure framework model is critical for the new development of this field, where over 250 wells per year are being drilled in various reservoirs.

The existing 3D seismic survey in Awali field was acquired in 1998. Though it was intended and initially processed as a narrow azimuth volume, it has been recently reprocessed in wide azimuth mode using new and advanced processing technology (Maili et al, EAGE-Copenhagen, 2012). This advanced processing was made possible by the particular acquisition geometry (cross spread with 8 receiver lines live), allowing for wide azimuth data in the upper part of section where many of the key oil producing reservoirs are located.

This new approach to structure framework building using automated workflows described here allows rapid framework updates to be made with data from newly drilled wells, and makes it possible to shorten the cycle time for geologic model building and maintain an "evergreen" model. This up-to-date structure framework also plays a key role in operations for planning new wells and drilling following-up.
From Empirical to Micro-scale Modeling of Multiphase Flow; Bridging the Gap of R&D
Authors: Al Qahtani Abdullah , Al Sultan Abdullah , Hadhrami Luai
Published: December 2013

In the petroleum industry, multiphase flows are complex phenomena and can be found in a variety of situations. The three more common working fluids (oil, natural gas and water) can have four different two-phase flow permutations of the three types of fluids. Multiphase flow modeling/metering is a key factor for optimal flow design and realizing optimal recovery of hydrocarbons. Over the last few decades, scientists developed the math of pressure and flow rate relationship in multiphase flow. A number of empirical correlations and mechanistic models have been developed for predicting pressure drop and other fluid flow characteristics during multiphase flow in wellbores and flow lines. Similarly, the emerging sensing and measurement tools were adapted for application of multiphase flow in oil and gas fields. With all calculation being computer-assisted and after many years of development and experimental research, the computer based numerical analysis methods have been evolved to solve the large number of equations and correlation coefficients. With the vast application of high performance computing, computational time is not an issue anymore but accuracy.

The challenges associated with multiphase flow modeling/metering include accuracy, size, application, and cost. The need for efficient and cost effective modeling/measurement systems in oil and gas fields have kept and will continue the need for active participation of R&D and better integration with sensing systems.

This paper reviews the state of art of modeling of multiphase flow and the major headways that led the way for subsequent research in this regard, and potential ways to promote accuracy and reduce cost. These are potential research projects being evaluated / proposed in the research institute in King Fahd University of Petroleum & Minerals in collaboration with international service providers and national field operators.
Lessons Learned from Perforated Liner Stuck in N. Azadegan Field
Authors: Rong Li , Huihong Luo , Kaicai Yu , Zhiping Li , Yansheng Lu , Qiang Wang
Published: December 2013

N.Azadegan oilfield is a laminar characteristic of bottom water limestone reservoir with about 50m thickness from hole toe to oil-water interface, so a water cone may exist. When water breaks through to the wellbore and reaches 10% in the field, the production well will be closed in accordance with Buy-back development contract. So all of 21 highly deviated wells and some horizontal wells are planned to use enough open-hole swell packers for preventing and managing water cut. But there is the few report about stuck perforated liner with swell packer in the high angle hole.

This paper discusses expandable experiments of swell packer in the lab and well completion string design such as packer’ setting placement, then give some risks analysis of running 4-1/2" perforated liner in 6" open hole such as severe dogleg in three dimension trajectory,144mm packer OD and rubber property, 1300m length open hole in higly deviated section and friction force etc. In the first 12 wells in N.Azadegan field, there are 4 wells’ cases of stuck 4-1/2" perforated liner with two or three packers. By reviewing the typical field cases of stuck perforated liner with packers in two wells, this paper analyzes several possible reasons include i.e. mud properties change, frequent trips to cause wellbore destruction, the severe dogleg, quick expansion after rubber absorb oil molecular and present the main reasons for stuck liner, then develop a solution that would allow the well of stuck perforated liner to be completed, finally focuses on modification of oil swelling packer from rubber element design to evaluation test based on in-suit mud. One of intentions in this paper is to give a case history and the lessons learned for further enhance the reliability of this kind of oil swelling packer, avoiding the risk of sticking perforated liner and promoting the use of swellable packer in the other field.
A Novel workflow for fracture characterization and well placement using BHI data in WBM and OBM in deep unconventional reservoirs of North Kuwait
Authors: Acharya Mihira N. , Chakravorty Sandeep , Rao Narhari S. , Darous Christophe , Al-Ajmi Saad A. , Joshi Girija K. , Al-Doheim Arif , Dashti Qasem , Al-Anzi Ealian H.
Published: December 2013

The tight deep carbonate reservoirs of Oxfordian age in North Kuwait consist of tight limestone interbedded with organic rich shale layers. The overall matrix porosity is generally very low and the production is mainly from fractures in the crestal part of main structures. Borehole images are routinely acquired in vertical to moderately deviated wells drilled with oil-base mud for fracture characterization.

For detailed fracture property evaluation, a highly deviated pilot hole was drilled with water-base potassium formate mud for the first time across the reservoir section and drill-pipe conveyed high-resolution electrical borehole image data was acquired. The upper half of the interpreted interval showed potential open fractures sets, NE-SW striking fracture set was most abundant. An advanced fracture segment extraction workflow was used to determine porosity and aperture of different fracture sets.

The first horizontal well was then drilled as a lateral in the target reservoir with oil-base mud restricting direct computation of fracture properties. The electrical and acoustic images in OBM indicated fracture concentrations at quite a few places along the horizontal well trajectory, the most conspicuous occurring at the zones where heavy mud losses were encountered while drilling. A 2D litho-structural model was constructed along the well trajectories using the dip data and open-hole logs to correlate finer carbonate and organic shale layers and fracture distribution across the layers. This workflow permitted extending fracture properties along horizontal well as well.

Finally, a high-resolution 3D structural model was constructed using outputs from previous workflows and data from two nearby vertical / less deviated wells. The final model showed a folded structure, which was absent in the existing model of the field. Thus the innovative workflow provides a means to generate an accurate structural and fracture model for the reservoir, integrating the fracture characteristics of the individual sub-layers with the main fracture corridors.
Estimation of Total Hydrocarbon in the Presence of Capillary Condensation for Unconventional Shale Reservoirs
Authors: Chen Jin-Hong , Mehmani Ayaz , Li Baoyan , Georgi Daniel , Jin Guodong
Published: December 2013

Accurate reserve estimates for unconventional shale gas reservoirs are critical to their economic assessment and field planning. Reserves are typically assessed with log and core measurements. Much of the log-derived information is validated with cuttings and core data. In particular, adsorption isotherms are measured in the laboratory and used to estimate ultimate recovery.

Accurate shale gas reserve estimations require a storage model that incorporates the physics of small scale, i.e., nanopores. This model is critical for the interpretation of log data and the prediction of long-term production and ultimate recovery. Current models partition gas into two parts: gas adsorbed on the pore surface with density comparable to liquid and free gas in the shale rock pores and natural fractures. Such a storage model, however, fails to consider the extremely favorable conditions for capillary condensation in the kerogen-rich rocks: pores in the kerogen range from a few nanometers to a few hundred nanometers and the pore surfaces are strongly oil wet. These two conditions are highly favorable for capillary condensation to occur; consequently, a significant amount of hydrocarbon probably exists in kerogen pores in the liquid state. Capillary condensation in shale gas core plugs has been verified in a laboratory study and significantly more hydrocarbons were observed than one would have expected in a traditional model that does not include capillary condensation.

We propose a new shale gas storage model for organic-rich shale rocks that accounts for capillary condensation. In this model part of the ‘gas’ exists in liquid phase inside kerogen pores. Capillary condensation is easy to model for single-component hydrocarbons. Under reservoir conditions, the hydrocarbons are usually a mixture of multiple components. This paper presents the method and theoretical result for estimating the total hydrocarbon volume for hydrocarbon mixtures in organic rich shales in the presence of capillary condensation.
Harnessing of Coal Energy Through Underground Coal Gasification (UCG) in India – Opportunities and Challenges in Processing and Utilisation of Syngas
Authors: Dani K. C. , Baskaran V. K. , Kumar K. , Varyani S. , Pokhriyal S. K.
Published: December 2013

India is blessed with large reserves of deep seated coal which cannot exploit economically with the available technology. The gap in demand and supply of energy is on rise for the nation. Underground coal gasification (UCG) is a way of accessing the un-mineable coal for its energy contents and as a chemical feed stock. The coal is converted into syngas insitu and the gas is produced on the surface. Coal mines in Gujarat in association with GIPCL the technology for UCG is being acquired from a Mining Institute of Russia. The site is selected through a process of detailed characterization of lignite seams. Detailed design for the surface layout, already been accomplished. Like surface gasification, the syngas in a UCG trial also needs to be cleaned up to make it usable. The extent of cleaning required depends on end use of the gas. The prevailing emissions and waste disposal regulations at location concerned also determine the equipment & process to be used for cleaning. The design of surface facilities for the Vastan pilot is aimed at maintaining the optimal parameters essential for stabilized gas composition and calorific value (CV). The ultimate goal is designing an environment friendly commercial plant. Major challenges in gas processing for the successful trial include identification of end usage of low CV syngas, separation of sticky condensate from gas, handling of CO2, ultimately turning it into an economical proposition. Opportunities during pilot run are securing technical and economic parameters of syngas processing and determination of economic utilization and most vital being the indigenization of the technology. The paper deals at length with likely difficulties to be handled and benefits to be accrued in the syngas processing in the trial. It covers pilot specific UCG process and facilities required at surface to refine the syngas.
Formation Kinetics of Gemfibrozil Chlorination Reaction Products: Analysis and Application
Authors: Krkošek Wendy H. , Peldszus Sigrid , Huck Peter M. , Gagnon Graham A.
Published: December 2013

Aqueous chlorination kinetics of the lipid regulator gemfibrozil and the formation of reaction products were investigated in deionized water over the pH range 3 to 9, and in two wastewater matrices. Chlorine oxidation of gemfibrozil was found to be highly dependent on pH. No statistically significant degradation of gemfibrozil was observed at pH values greater than 7. Gemfibrozil oxidation between pH 4 and 7 was best represented by first order kinetics. At pH 3, formation of three reaction products was observed. 4′‐ClGem was the only reaction product formed from pH 4–7 and was modeled with zero order kinetics. Chlorine oxidation of gemfibrozil in two wastewater matrices followed second order kinetics. 4′‐ClGem was only formed in wastewater with pH below 7. Deionized water rate kinetic models were applied to two wastewater effluents with gemfibrozil concentrations reported in literature in order to calculate potential mass loading rates of 4′ClGem to the receiving water.
Socio-political status of Serbs in the Habsburg Monarchy from the privileges of Leopold to declaratoria
Authors: Gavrilovic Vladan , Mikavica Dejan
Published: December 2013

The authors begin with the defining of the Serbian privileges 1690-1695 and
their different interpretations by the Austrian (imperial) and Hungarian
(county) government. For the Viennese court, Serbs were a nation (natio
Rascianica), while for the Hungarian classes they were just a recognized
religious group living in the ancient Hungarian territory. Because of these
two different opinions, the privileges were the most important thing for the
Serbs living in the territory of Hungary. At the same time, the Viennese
court repeatedly upheld Serbian privileged status, but with various
restrictive clauses. Serbian privileges were considerably reduced over time
and, finally, in the seventies of the 18th century they were completely
devalued.
Social vitality in rural development research
Authors: Cikic Jovana
Published: December 2013

Rural community development is one of the central rural sociological
concepts. The idea itself deserves double attention: from the point of its
theoretical foundation and from the perspective of the need to be
operationalized because of research and rural development planning. In this
paper, the idea of rural development is being approached from the aspect of
social vitality as a new/old concept. The concept of social vitality is being
defined and operationalized in order to indicate the possibilities of this
concept as an analytical tool for researching rural development.
A low-cost automated flow analyzer based on low temperature co-fired ceramic and LED photometer for ascorbic acid determination
Authors: Pessoa-Neto Osmundo , Santos Vagner , Vicentini Fernando , Suarez Willian , Alonso-Chamarro Julián , Fatibello-Filho Orlando , Faria Ronaldo
Published: December 2013

An automated flow analyzer based on low temperature co-fired ceramic (LTCC), a solid-phase reactor (SPR) and a low-cost photometer was designed for ascorbic acid (AA) determination in pharmaceutical formulations. It consists of a peristaltic pump, three-way solenoid valves, SPR to chemically convert Cu(II) into Cu(I), and a LTCC device for mixing the liberated copper with bathocuproine and detection. The flow cell in the LTCC employed an ultrabright LED — photodiode photometer. The analyzer successfully determined AA in pharmaceutical formulations. The analytical curve from 8.5×10−6 to 7.0×10−4 M gave a detection limit of 7.0×10−7 M and a RSD of 2.1% for a 2.0×10−4 M AA solution (n = 10). A high sampling frequency of 102 h−1 and low reagent and sample consumption (150 µL) resulted.
Solvent extraction with organophosphorus extractants in environmental samples: determination of cadmium(II) in natural water
Authors: Mánuel Victoria , Pinto Juan , Mendiguchía Carolina , Moreno Carlos
Published: December 2013

In this work, Cd(II) extraction in natural waters by organophosphorus extractants as organic phase, as well as its back-extraction in an acidic media, has been studied. Cadmium extraction behavior at natural waters’ pH conditions (values in the range 7–8) was studied with two different extractants and co-ions, obtaining the highest extraction efficiency when using 0.1M Cyanex 272 in kerosene as organic phase and 0.1 M NO3
− as co-ion. Once they were selected, the effect on the extraction efficiency of sample pH, buffer concentration, extraction time, Cyanex 272 concentration as well as back-extractant concentration, was studied. The presence of the main inorganic and organic ligands in the sample was also studied, observing that extraction efficiency was affected most significantly when chlorides were present, with a decrease of about 14%, proving negligible for the others. Under the selected conditions, spiked real samples were successfully analyzed.
The exploration of interaction studies of smaller size, mostly ignored yet intrinsically inestimable molecules towards BSA; An example of STD and DOSY NMR
Authors: Tanoli Sheraz , Tanoli Nazish , Usmani Saman , Zaheer-Ul-Haq  , Ferreira Antonio
Published: December 2013

Larger size or novel structure molecules are always appreciated by all fields of experimental and computational science. Conversely, molecules with smaller size and simple structures are usually ignored with no explanation as to why. However, the vast majority of more diminutive molecules behave as a cornerstone in the synthesis of a bigger structural framework. Subsequently, we planned to uncover the interactions of small molecules towards macromolecules, and successfully presented the binding results of 2-aminopyridine and Isovanillin towards BSA through NMR techniques. STD epitope mapping and also the DOSY results provided evidence that Isovanillin remained closer to the binding cavity of protein. Titration experiments afforded 584 µM (0.584mM) and 487 µM (0.487 mM) dissociation constants for isovanillin and 2-aminopyridine respectively. Furthermore, changes in diffusion coefficient (with and without protein addition in DOSY spectra) were found to be 0.081 log (m2 s−1) and 0.096 log (m2 s−1) points for isovanillin and 2-aminopyridine respectively. Docking studies exhibit that these molecules can tie to site 1 (sub-area IIA) through the pi-pi interaction and hydrogen bonding with Trp213. Our results demonstrated that both compounds could be utilized as part of a transporter in the circulatory system and their extension-inspired compounds may be utilized in new drug design.
Crystallographic and structural characterization of heterometallic platinum complexes Part V. Heteropentanuclear complexes
Authors: Melník Milan , Mikuš Peter , Holloway Clive
Published: December 2013

This review classifies and analyzes over eighty heteropentanuclear Pt complexes. There are eight types of metal combinations: Pt4M, Pt3M2, Pt2M3, PtM4, Pt3MM′, Pt2M2M′, PtM2M′2 and PtM3M′. The five metal atoms are in a wide variety of arrangements: trigonal-bipyramidal (most common), square-pyramidal, spike-triangular, butterfly, cubane, linear and one unique. Platinum bonds to a variety of triad partner metal atoms, soft, through borderline to hard. The shortest Pt-M bond distances for non-transition and transition M are 2.406(4) Å (M = Ge) and 2.30(1) Å (M = Co). The shortest Pt-Pt bond distance is 2.580(1) Å. Several relationships between the structural parameters were found and are discussed. Several complexes exist in two isomeric forms and others contain two crystallographically independent molecules. Both the isomers as well as independent molecules are examples of distortion isomerism.
Spectroscopic route to monitoring individual surfactant ions and micelles in aqueous solution: A case study
Authors: Geng Junfeng , Johnson Brian , Wheatley Andrew , Luo Jack
Published: December 2013

Using a very popular and commonly used surfactant sodium dodecylbenzene sulfonate (SDBS, C18H29SO3Na) for a case study, we report a new method of monitoring different forms of surfactant molecules in aqueous solution and measuring their critical micelle concentration (CMC) by ultraviolet-visible (UV-Vis) spectroscopy. The forms of SDBS micelles are also investigated by synthesizing and characterizing NiB nanoparticles using the micelles as molecular templates. In addition, the observed shifts of UV-Vis bands are analysed from the viewpoint of the electrons locations and distributions within the molecules and the possible overlap of their electronic orbitals between neighbouring molecules in each micelle.
Solid contact Zn2+ -selective electrode with low detection limit and stable and reversible potential
Authors: Wardak Cecylia
Published: December 2013

A new solid contact Zn2+ polyvinylchloride membrane sensor with 2-(2-Hydroxy-1-naphthylazo)-1,3,4 -thiadiazole as an ionophore has been prepared. For the electrode construction, ionic liquids, alkylmethylimidazolium chlorides are used as transducer media and as a lipophilic ionic membrane component. The addition of ionic liquid to the membrane phase was found to reduce membrane resistance and determine the potential of an internal reference Ag/AgCl electrode. The electrode with the membrane composition: ionophore: PVC: o-NPOE: ionic liquid in the percentage ratio of (wt.) 1:30:66:3, respectively, exhibited the best performance, having a slope of 29.8 mV decade−1 in the concentration range 3×10−7–1×10−1 M. The detection limit is 6.9×10−8 M. It has a fast response time of 5–7 s and exhibits stable and reproducible potential. It has a fast response time of 5–7 s and exhibits stable and reproducible potential, which does not depend on pH in the range 3.8–8.0. The proposed sensor shows a good and satisfactory selectivity towards Zn2+ ion in comparison with other cations including alkali, alkaline earth, transition and heavy metal ions. It was successfully applied for direct determination of zinc ions in tap water and as an indicator electrode in potentiometric titration of Zn2+ ions with EDTA.
Inverse problems on star-type graphs: differential operators of different orders on different edges
Authors: Yurko Vyacheslav
Published: December 2013

We study inverse spectral problems for ordinary differential equations on compact star-type graphs when differential equations have different orders on different edges. As the main spectral characteristics we introduce and study the so-called Weyl-type matrices which are generalizations of the Weyl function (m-function) for the classical Sturm-Liouville operator. We provide a procedure for constructing the solution of the inverse problem and prove its uniqueness.
Relation modules of infinite groups, II
Authors: Evans Martin
Published: December 2013

Let F
n denote the free group of rank n and d(G) the minimal number of generators of the finitely generated group G. Suppose that R ↪ F
m ↠ G and S ↪ F
m ↠ G are presentations of G and let $$\bar R$$ and $$\bar S$$ denote the associated relation modules of G. It is well known that $$\bar R \oplus (\mathbb{Z}G)^{d(G)} \cong \bar S \oplus (\mathbb{Z}G)^{d(G)}$$ even though it is quite possible that . However, to the best of the author’s knowledge no examples have appeared in the literature with the property that . Our purpose here is to exhibit, for each integer k ≥ 1, a group G that has presentations as above such that . Our approach depends on the existence of nonfree stably free modules over certain commutative rings and, in particular, on the existence of certain Hurwitz-Radon systems of matrices with integer entries discovered by Geramita and Pullman. This approach was motivated by results of Adams concerning the number of orthonormal (continuous) vector fields on spheres.
Minority carrier recombination lifetimes in n-type CdMgSe mixed crystals measured by means of the photothermal infrared radiometry
Authors: Pawlak M. , Maliński M.
Published: December 2013

Minority recombination lifetimes of n-type CdMgSe mixed crystals were estimated by using infrared photothermal radiometry (PTR) amplitude and phase frequency spectra. The results obtained by the PTR method indicate that the lifetimes of optically generated carriers in CdSe and CdxMg1−xSe crystals are about 0.1 μs. The diffusion length of minority carrier in n-type CdSe single crystal was found to be 4.42 μm and it is in a good agreement with the literature value. It was found that with the increasing thermal-to-plasma component coefficient A the carrier concentration increases as expected from PTR theory.
Enhancement in UV emission and band gap by Fe doping in ZnO thin films
Authors: Srivastava Anchal , Kumar Nishant , Khare Sanjay
Published: December 2013

Enhancement of the optical band gap of ZnO from 3.14 to 3.29 eV has been obtained using Fe dopant. Undoped and doped ZnO films are deposited by sol-gel spin coating. XRD patterns indicate polycrystalline nature and hexagonal wurtzite structure of Zn1−xFexO films. EDX analysis confirms the presence of iron dopant. The photoluminescence spectra show an ultraviolet emission peak at 398 nm (NBE emission) and defect emission peak at 485 nm. Intensity of the NBE emission is much higher for the doped samples with its ratio to defect emission intensity highest for 2 at. %doping. The NBE emission shifts to higher energy with increasing dopant concentration in a manner similar to that exhibited by the band gap. Surface morphology has been studied using FESEM.
Senior Poverty in Canada: A Decomposition Analysis
Authors: Schirle Tammy
Published: December 2013

Using 1977–79, 1994–96, and 2006–08 data from the Survey of Consumer Finances (SCF) and Survey of Labour and Income Dynamics (SLID), I conduct a decomposition analysis of senior poverty rates to determine whether changes in seniors’ characteristics can help explain historical changes in senior poverty rates. I find that increases in the educational attainment of seniors significantly reduced senior poverty, but can only explain a small portion of the reduction in poverty rates between 1977–79 and 1994–96. I find that reductions in the extent to which age and independent living place seniors at risk of poverty significantly and substantially reduced senior poverty rates. Overall, the results support the assertion that retirement income policy is an important determinant of senior poverty in Canada.