bluuebunny/crossref_metadata_2025_split huggingface dataset:
Controls on the Lower Cretaceous Carbonate Habitats of the South Porcupine and Goban Spur Basins, Offshore Ireland
Authors: O'Sullivan J. M. , Jones S. M. , Hardy R. J. 
Published: December 2009

Abstract
Exploration drilling together with 2D seismic data suggests the presence of an extensive Lower Cretaceous carbonate depositional province in the South Porcupine and Goban Spur Basins, offshore southwest of Ireland. Interpreted environments of deposition range from large scale carbonate shelf development through platform margin to isolated offshore carbonate build-ups. During the Late Jurassic to Early Cretaceous period, these basins underwent a phase of normal detachment faulting and regional subsidence associated with high degrees of lithospheric extension. This phase of tectonic activity is interpreted to have exerted a primary regional control on carbonate development in two ways: rapid development of accomodation space limited the influence of clastic sediment input in basin margin depocentres; and the rotated, up-standing footwall crests of normal fault blocks provided intra-basinal bathymetric shoals for carbonate colonisation. Locally, both eustatic and isostatic changes are interpreted to have controlled carbonate deposition, providing a linkage from macro-scale stress fields to micro-scale reservoir architecture. Trophic conditions such as paleo-latitude, ocean circulation and wind direction appear to have exerted a secondary influence on carbonate development. These Lower Cretaceous carbonate sequences can be correlated with world class petroleum reservoirs which span the northern hemisphere from the Middle East to the Gulf of Mexico. Such carbonate systems could form the basis of an important paradigm shift away from the traditional Mesozoic clastic-dominated play systems of the Atlantic Margin in the future exploration of these emerging frontier deepwater basins.
Novel Activation Fluid System
Authors: Rickman Richard , Allison Dave , McCabe Mike , Janson Jon 
Published: December 2009

Abstract
The success of producing gas from unconventional resources, such as shales, is often tied to maximum exposure to the reservoir. Usually this is achieved by drilling horizontal wellbores and creating fractures that originate from multiple points along the wellbore. Each fracture "stage" must be isolated from the previous stage so as to create additional unique flow paths for the gas. One mechanism to create the fracture isolation points is to use chemical swelling packers between the liner and the formation. These chemical swelling packers can be swollen using water-based fluids, hydrocarbon-based fluids, or combinations of both.
Certain shale formations, like the Lower Huron and Marcellus, are often drilled with air or foam. One reason for air drilling is that these formations have shown a propensity to incur damage from traditional drilling fluids (both hydrocarbon- and water-based). Because of this, there can be reluctance to use traditional fluid systems to activate chemical swelling packers in these formations.
This paper documents the laboratory investigation and development of a novel activation fluid system that minimizes the potential damage to the reservoir but still permits operations to take advantage of the unique characteristics of the chemical swelling packer. Included is a discussion of the operational issues encountered to "scale up" for the first field trials and the results of the first commercial applications.
Plugging and Abandoning Multilateral Horizontal CBM Wells for Safe Mine through Operations
Authors: Suhy Thomas E. 
Published: December 2009

Abstract
Since the first commercial sale of Coalbed Methane (CBM), the process of drilling and producing methane with multilateral horizontal wells has been a "win-win" plan for the entire coal industry in North America. It creates a revenue stream by exploiting a valuable resource while de-gassing coal and lowering safety risks ahead of mining operations. Modern CBM wells are usually drilled up dip, in a tri-lateral "Turkey Track" pattern. Each lateral extends approximately 4000’ beyond the horizontal build section.
Normal mining operations allow approximately ten years of production to produce and deplete the adsorbed gas contained in the coal. Recent increased energy demands with favorable market increases have accelerated the mining schedules and shortened the available gas production time. These factors have lead to hazardous conditions encountered when mining through the yet depleted lateral well bores where dangerous volumes of trapped methane can inundate the occupied mine work area. Currently, mine operators are forced to use water infusion and in-mine drilling and grouting operations to safely intersect the horizontal well bores. This results in costly mine production delays.
The best solution requires a stable medium that can be positively placed through the extent of the well laterals and effectively displace and fill void spaces where methane gas can accumulate. This paper will explore and evaluate the results of applying variety of products, equipment, and techniques solve this quandary.
A Novel Foaming Agent for Hydraulic Fracturing: Laboratory Investigation and Field Usage
Authors: Lin Lijun , Danican Samuel C. , Mueller Fred A. 
Published: December 2009

Abstract
A series of surfactants were evaluated in this study and the results were compared with conventional foaming agents used in fracture fluids. These surfactants were examined by surface tension measurements, bench-top foam height and half-life experiments, and viscosity measurements on a circulating foam rheometer. The foam rheometer allowed viscosities to be measured under conditions that are representative of those found in formations. Both nitrogen (N2) and carbon dioxide (CO2) foams were investigated. This paper presents detailed results obtained from laboratory experiments, which led to the identification of foamer A that exhibited excellent performance in the presence of nitrogen and carbon dioxide over a wide range of temperatures. Foamer A was found to be superior compared with conventional foamers, particularly at high temperatures. It is compatible with linear gels as well as crosslinked fluids commonly employed for fracturing treatments. Numerous fracturing treatments with foamer A have been successfully executed in the field.
It is emphasized in the paper that the type of foamer used in fracturing treatments has a great impact on the resulting foam stability and viscosity. In addition, bench-top foam height and half-life experiments can give an indication of the performance of a specific surfactant, but its behavior under downhole conditions cannot necessarily be inferred accordingly.
Viscoelastic Surfactant-Based Systems in the Niagaran Formation
Authors: Kreh Kristopher A. 
Published: December 2009

Abstract
The Niagaran formation in the Michigan basin is comprised of Silurian Pinnacle reefs. It is a heterogeneous carbonate formation with the majority being dolomite. There are two Niagaran plays in Michigan, the Northern Play and the Southern Play. Past stimulation treatments on the Niagaran have consisted of mainly hydrochloric acid at concentrations of 15-28%. Most treatments were kept to matrix conditions due to water zones in close proximity. These treatments usually yield marginal results due to the acid being spent mostly near well bore. Gelled, crosslinked or emulsified acid are good solutions for this problem but can also leave some damage behind. Acid gelled with surfactants can yield similar results and be easier to clean up.
This paper will provide some background on the Niagaran formation and historical treatments. The paper will explain the chemistry behind viscoelastic surfactant-based acid systems and will provide detailed descriptions of the benefits of these types of systems. Production data from a well treated with both conventional acid and a viscoelastic acid system will be discussed. The paper will then conclude with a few words on the economics behind viscoelastic systems.
Production Forecast of Fractured Well in Tight Gas Reservoir, Accounting for 3D Fracture Geometry and Variable Fracture Conductivity
Authors: Jin X. , Wei Y. 
Published: December 2009

Abstract
Producing natural gas from Tight Gas Sand (TGS) reservoirs is currently very important to the industry in North America and will be of increasing importance to the global energy industry in the coming decades. Productivity index (PI) is an important indicator of a well’s production capacity. For conventional reservoirs, well productivity is usually calculated using the pressure response of the reservoir in its pseudo-steady state period. However, for TGS reservoir, the period of transient flow covers a larger part of the well lifetime and the pseudo-steady state productivity calculations become less applicable in prediction of the reservoir’s production behavior. The Distributed Volumetric Sources (DVS) method can fill this gap. The DVS method can be used to predict the productivity index of a general well completion scheme for both transient flow period and pseudo-steady state flow period. In the paper, we will generally describe the DVS method and the model we have build to predict the PI of TGS reservoir using DVS method.
In this study, we focus on a typical well completion scheme — vertical well intersected by a vertical fracture of finite conductivity. Parametric study is performed by varying the proppant pack permeability with a linear distribution, varying fracture width with an elliptical distribution and varying fracture height with an elliptical distribution. The details of hydraulic fracture are integrated into the calculation of well productivity. By combining the well productivity with gas material balance, production forecasting of the hydraulically fractured wells could be easily obtained. The result of production forecasting could be used to aid in decision making of choosing the best stimulation treatment. Field examples are presented to illustrate the application of this technology for production modeling the complicated reservoir cases involving fracture stimulation.
A Practical Approach to Initial Production (IP) Rate Estimation for Infill Oil Wells
Authors: Eruvbetine Obor , Odusote Olufemi , Aitokhuehi Inegbenose , Imogu Moses , Ekeng Oyie 
Published: December 2009

Abstract
Asset development teams have the responsibility of identifying, evaluating and executing infill well opportunities. In maturing these projects, realistic forecasts are needed. An intrinsic part of these forecasts is the initial rate of production, which influences the economic viability of the opportunity and the producing life of subsequent facilities. It is every team's desire to come up with a range of producible rates given reservoir, wellbore and surface constraints. This would serve as the basis for the decisions regarding rates of production. Inflow-outflow modelling (nodal analysis) is generally the accepted method for rate prediction. However, data and time constraints such as unreliable well tests, BHP surveys and questionable PVT data can make rate determination very challenging.
This paper details a methodology to overcome these obstacles through the application of a two-dimensional approach to deriving a range of production rates using both integrated modelling and analog comparisons. The 2-step approach involves building an integrated production model that includes wellbore models connected to a surface production network (could be built to varying levels of complexity). The results from the network model are tuned using an acceptable set of well test data from analog reservoirs. The end result is a more realistic range of IP rates that are representative of the opportunity under evaluation.
The workflows detailed in this paper were used to derive forecasts for infill oil wells in the offshore Niger Delta. A few of these have been drilled and many are currently being evaluated, some of the challenges, lessons learned and results are also shared in this paper.
Risk Identification Report and Employee Motivation - Strategy for Capacity Development in the Nigeria Energy Sector.
Authors: Tubosun Fagbe 
Published: December 2009

ABSTRACT
The study sought to identify the positive effect of prompt report of identifiable risks and hazards in the Nigeria Energy sector by her workforce and other parties involved in Oil and Gas business. Two broad types of data, the secondary and primary data were used in the study. Interviews and personal observation within an Oil Exploration Company was also used for the purpose of establishing role of employee motivation on Risk Identification report.
Furthermore, factors impeding the effective and efficient risk reporting were identified, wrong attitudes and perceptions of people about safety issues that contributed to rising rate of accident most especially the fire outbreak in Nigeria was also highlighted. It is disheartening to note that majority of Nigerians did not have basic safety training in the colleges, homes and at work. Therefore this paper will be useful in creating awareness to the teeming Nigerians especially the locals that are engaged in Seismic and other associated Oil and Gas operation on timely Risks identification and reporting.
In addition, findings revealed that monthly reward of Safety conscious employee reduces the probable accident rate in the Oil Sector. It was recommended that all staff and stakeholders in the Oil and Gas Companies should be given adequate training on Risk Identification, reporting and preventive management technique along with standardized recognition of diligent workers through awards, promotion and further training.
A Hybrid Approach To Assess Decommissioning Options for Offshore Installations
Authors: Andrawus Jesse A , Steel John A , Watson John F 
Published: December 2009

Abstract
Decommissioning of offshore installations is increasingly becoming a crucial issue to the Oil and Gas industry as most assets within the sector are approaching the end of their economic life. Common decommissioning options include complete removal, partial removal and re-use. Inappropriate selection of a decommissioning option can have severe financial, environmental, health and safety consequences. The best available option is usually determined by taking into account technical feasibility, economic viability, consumption of natural resources and, health, safety and environmental impact.
Net Present Value (NPV) analysis is often used to assess the economics of decommissioning options. However, an economic analysis based on purely financial criteria is not in itself adequate for valid decision making. Non-financial factors which are not reducible to monetary values should be identified and incorporated into the overall economic analysis. Weighted Evaluation (WE) is a technique used to assess the feasibility of non-financial factors. In this paper, a hybrid of NPV analysis and WE technique has been developed to assess the economic and technical viability of decommissioning options. The hybrid technique is used in a case study to assess and compare the impact of different decommissioning options on a selected Oil and Gas platform. An appropriate decommissioning option with minimum combined financial, environmental, health and safety impact is determined.
Multidisciplinary Approach to Optimising Hydrocarbon Recovery From Conventional Offshore Nigeria: OML100 Case Study
Authors: Faseemo O. , Massot J. , Essien N. , Healy W. , Owah E. 
Published: December 2009

Abstract
Optimisation of hydrocarbon recovery from mature fields has always been very attractive in the petroleum industry. This will increasingly be of great importance going by the complexity of making new commercially viable hydrocarbon discoveries, and the high cost and long delays of bringing new discoveries into production.
OML100 is a conventional offshore block located 80 km south-east of the Nigerian coast and operated by Total E&P Nigeria in partnership with the Nigerian National Petroleum Corporation (NNPC). It comprises four producing fields, namely: Afia, Edikan, Ime and Odudu; and two other fields which are currently being studied for subsequent development.
Field development started in 1993 with oil production reaching a plateau of 70 MBD between 1995 and 1998. Due to sound reservoir management practices and collaboration with other entities, 39% hydrocarbon recovery has been achieved in the 16 years of production. Today the block faces series of challenges militating against the realisation of more than 50% recovery which is our base case objective. These challenges include: ageing surface facilities, increasing gas and water handling challenges, sand production, loss of wells, insufficient well activation, limited reservoir pressure maintenance, by-passed oil and remaining reservoir uncertainties.
This paper highlights practical multi-disciplinary approaches that are being employed in order to maximise oil production, at minimum cost, from the four fields located in a challenging offshore environment. Reference is made to standard definitions of conventional offshore and mature oil fields. This is followed by a review of the development history, status and challenges of the fields. Methods towards continual optimal reservoir surveillance and exploitation are discussed as a case study and these include: seismic data reprocessing and reinterpretation, review of geological models, update of reservoir synthesis and models, infill development proposals, sand bailing and zone change operations, improved well activation project, surface facilities integrity project, dedicated pressure maintenance and polymer-surfactant injection projects.
Simultaneous determination of retinol, retinyl palmitate and β-carotene in rat serum treated with 7,12-dimethylbenz[a]anthracene and Hypericum Perforatum L. by high-performance liquid chromatography with diode-array detection
Authors: Levent Abdulkadir , Ekin Suat , Oto Gökhan 
Published: December 2009

Abstract
A new and simple high-performance liquid chromatography method was developed and validated for the simultaneous determination of retinol, retinyl palmitate and β-carotene in rat serum treated with Hypericum Perforatum L. and 7,12-dimethylbenz[a]anthracene. Furthermore, vitamin C was determined spectrophotometrically. High-performance liquid chromatography analysis was performed utilizing an Inertsil ODS3 reversed phase column with methanol-acetonitrile-tetrahydrofuran (65:30:5, v/v/v) as mobile phase, at a flow rate of 1.5 mL min−1 and 40°C. Diode-array detection was conducted at 325 and 450 nm for retinol and retinyl palmitate, and β-carotene, respectively with a running time of 26 min. The high-performance liquid chromatography assay and extraction procedure proposed are simple, rapid, sensitive and accurate. This method was then applied to determine the amounts of retinol, retinyl palmitate and β-carotene in rat serum. Results of this study demonstrated that at 60th day in the 7,12-dimethylbenz[a]anthracene-treated group there was a significant decrease (pa] anthracene + Hypericum Perforatum L. treated group compared to the control group..
Design of an amperometric xanthine biosensor based on a graphite transducer patterned with noble metal microparticles
Authors: Dodevska Totka , Horozova Elena , Dimcheva Nina 
Published: December 2009

Abstract
A mesoporous graphite material micro-structured with palladium-platinum deposits (mixed in the ratio of 70:30% Pd:Pt) has been used as a cost-effective electrode material for designing an amperometric biosensor for xanthine. The here reported biosensor shows significantly improved operational parameters as compared to previously published results. At a constant applied potential of −0.05 V (vs. Ag/AgCl) it is distinguished with enhanced selectivity of the determination: at the working potential the current from the electrochemical transformation of various electrochemically active substances usually attending biological fluids (incl. uric acid, L-ascorbic acid, glutathione and paracetamol) has been eliminated. The effect of both the temperature and buffer composition on the analytical performance of the sensor has been investigated. Under optimal operational conditions (25°C, −0.05 V vs. Ag/AgCl, phosphate buffer, pH 8.4), the following have been defined for the biosensor: sensitivity 0.39 µA µM−1, strict linearity of the response up to xanthine concentration 70 µM, detection limit of 1.5 µM (S/N=3) and a response time of at most 60 s.
Synthesis, characterization and biological activities of homo-binuclear Cu(II) and Zn(II) complexes derived from 2-hydroxy-5-methyl-1,3-benzenedicarboxaldehyde derivatives
Authors: Raman Natarajan , Sakthivel Arumugam , Jeyamurugan Ramaraj 
Published: December 2009

Abstract
Few novel binuclear Schiff base metal complexes [M2LCl3], where M = Cu(II) and Zn(II); L= 2,6-bis-({2-[(3-hydroxy-4-nitrobenzylidene)amino]ethylimino}methyl)-4-methylphenol (BHEM), 2,6-bis-({2-[(3,4-dimethoxybenzylidene)amino]ethylimino} methyl)-4-methylphenol (BDEM) and 2,6-bis-({2-[(2,3,5-trichlorobenzylidene)amino]ethylimino}methyl)-4-methylphenol (BTEM), have been synthesized and characterized by analytical and spectral data. The data suggest that BHEM/BDEM/BTEM ligands afford square-pyramidal/distorted square-pyramidal geometry on metalation with Zn(II)/Cu(II). The binding behaviour of these complexes with DNA has been investigated using electronic absorption spectroscopy as well as viscosity and voltammetric measurements; the results show that they interact with DNA through intercalating way. From the DNA cleavage study of these complexes, investigated by gel electrophoresis, we found that they efficiently cleave supercoiled pUC19 DNA in the presence of a reducing agent (3-mercaptopropionic acid) and on irradiation with UV light of 360 nm wavelength. The mechanism reveals that singlet oxygen (1O2) plays a significant role in the photo cleavage. The superoxide dismutase (SOD) mimetic activity of the synthesized complexes demonstrates that most of the complexes have promising SOD-mimetic activity. The antimicrobial study indicates that the complexes inhibit the growth of bacteria and fungi more than the free ligands.
Catalytic activity of thiourea and its selected derivatives on electroreduction of In(III) in chlorates(VII)
Authors: Nosal-Wiercińska Agnieszka 
Published: December 2009

Abstract
It was found that thiourea, N-methylthiourea, N,N′-dimethylthiourea and N-allylthiourea accelerate the electroreduction process of In(III) ions in chlorates(VII). These substances are adsorbed on mercury from chlorates(VII). The relative surface excesses of thiourea and its derivatives increase with the increase of their concentrations and electrode charge. After adding thiourea, N-methylthiourea, N,N′-dimethylthiourea and N-allylthiourea to the solution an acceleration of the electroreduction process of In(III) ions occurs. This process depends on two factors: the adsorption of an accelerating substance on mercury and on the formation of complexes between a depolarizer and an accelerating substance on the electrode surface. The equilibrium of this complexing reaction determines the magnitude of the catalytic effect.
SOBP forming for carbon therapy
Authors: Babkin Vadim , Cata-Danil Gheorghe , Golovatyuk Viacheslav , Molokanov Aleksandr , Paraipan Mihaela , Timoshenko Gennady 
Published: December 2009

Abstract
A ridge carbon beam filter for Spreading Out the Bragg Peak (SOBP) up to 20 mm in the targeted area has been designed and experimentally tested. The instrument was constructed of Plexiglas with a density of 1.165 g/cm3 and has a “teeth” structure with a period of 2.5 mm. The design is based on a simple analytical model and detailed GEANT4 Monte Carlo simulations. In-beam test measurements were performed with a 500-MeV/u 12C beam at the Nuclotron facility of the Joint Institute for Nuclear Research (JINR) in Dubna. The filter can be used as a static device positioned in front of patients undergoing carbon therapy.