bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detailed Mineralogy and Organic Carbon Detection Through Casing Using Pulsed Neutron Technology - A Case Study in a Carbonate Formation (KY)
Authors: Mendez Freddy E. , Siddiqui Aamir , Hanif Amer , Longo John , McGlynn Ian , Gade Sandeep , Blood David R. 
Published: September 2015

Abstract
Spectral analysis of natural and stimulated gamma rays is a well-established open-hole technology that enables accurate mineral characterization and petrophysical evaluation of conventional and unconventional reservoirs. The determination of detailed mineralogy in the cased-hole environment, however, has been a challenge because of the significantly increased uncertainties caused by the additional attenuation and contribution effects of casing and cement that are observed in the gamma ray spectra. The acquired spectral gamma ray data is processed with proprietary algorithms that are based on a combination of lab experiments and modeled tool response standards. The resulting elemental composition, corrected for the cased-hole environment, is further processed in an expert interpretation system to determine lithology and detailed mineralogy of the target formation. Candidates for this technology include older and newly cased wells where lithology and detailed mineralogy from open-hole logs are not available.
This work discusses some aspects of the corrections needed for an accurate quantification of chemical elements from measurements through casing. The impact of casing collars and presence of cement on the spectral data are also discussed. Finally, we report a case study that uses this technology and illustrates a successful mineral characterization of a complex reservoir rock in the United States. Results show good agreement with an x-ray difraction (XRD) analysis of ditch cuttings. The resulting logs were productively used by the operator to understand the siliciclastic influx as well as the distribution of carbonates in the Big Lime formation. The results also show the ability of the methodology to identify organic carbon directly from measurements of the inelastic spectrum in the cased-hole environment.
The application of pulsed neutron technology (PNT) in cased holes has, so far, been limited to basic lithology identification. This methodology expands the applicability of the PNT, previously mostly confined to open-hole cases, to the cased-hole environment and enables operators to take full advantage of the valuable information contained in high-resolution inelastic, capture and natural spectra. This enables characterization of hydrocarbon-bearing formations to a level of detail previously possible only from open-hole data.
A Sulfur-Free and Biodegradable Gel Stabilizer for High Temperature Fracturing Applications
Authors: Chetan Prakash , Songire Sumit 
Published: September 2015

Abstract
For a successful hydraulic fracturing operation, two of the most important properties required from fracturing fluids are transport proppant into the fractured zone and minimum damage to formation and proppant pack conductivity. As the fluid is pumped downhole, it experiences thermal and shear thinning. Shear recovery and thermal stability are critical in terms of successful fracture creation and proppant placement. These fluid properties can be controlled by proper selection of crosslinker and linkable groups. Thermal stability of fluid at high temperatures can be increased by proper selection of gel stabilizers and it also reduces the amount of gelling agent to be used. Conventional gel stabilizer contains sulfur which could contribute to H2S gas when consumed by sulfate reducing bacteria. H2S gas is not only corrosive in nature but also harmful to health and thus, although it performs well, several operators seek sulfur-free stabilizers that can perform equivalent to sulfur-based compounds.
This paper describes a sulfur-free gel stabilizer developed for enhancing the stability of fracturing fluid, allowing a lower concentration of gelling agent. This gel stabilizer is sulfur-free, nonhazardous, and biodegradable. It also provides better stability for fluids compared to conventional sulfur containing gel stabilizers.
Further showcased is the improvement in stability of crosslinked fracturing fluid using the sulfur-free stabilizer under high temperature (HT) conditions of 280 to 320°F. Rheological tests performed using a Chandler high-pressure/high-temperature (HP/HT) viscometer with and without stabilizer are discussed. Results shows a significant change in terms of fluid stability in the presence of this new stabilizer as it provides better stability compared to conventional sulfur containing stabilizer. Also, shear sensitivity tests performed under multiple high shear rate cycles between 100-935-1700 s-1 showed excellent shear recovery after every high shear cycle by completely rehealing in less than 30 seconds.
Solving Swelling Clay Issues in Egypt's Western Desert: Combination of Fluid Engineering and Steel-Body PDC Bit Displaces Roller Cone in Large Hole Section
Authors: Ahmad M. F. , Hussein M.. , Abd El-Azm H. M. , Hanafy O.. , Eloufy M.. , Ibrahim S.. , Aguib K.. , Farouk A. A. , Sabry M. A. 
Published: September 2015

Abstract
Drilling the top hole section in Egypt's Western Desert has proven to be a challenge because finding the optimal balance of drilling speed, pulling out of hole without issue, and running the casing without clay swelling is critical. Historically, a standard milled-tooth (MT) bit, slick BHA, and top hole mud system were used for economic considerations. Recently, a problem arose when drilling a 17½-in surface hole in the Western Desert Moghra sand and Dabaa area, where the formation is composed of swelling clays that caused delays and cost increases.
The solution to combat clay swelling would require an effective mud strategy; a PDC design that could increase ROP and resist balling while remaining economic; and a slick BHA that ensured hole verticality without the aid of directional tools and minimizes the affect of drillstring dynamics for prolonged PDC bit life. The intent of such optimization is providing enough buffer time for the casing to be run without problems, and the overall solution needs to be more economic than the previous drilling practice.
An integrated BHA, bit design, and mud strategy were deployed in a field test with outstanding results. The results showed a step-change in ROP performance and allowed a trouble-free hole. The PDC bit and slick BHA successfully mitigated vibrations and maintained verticality. The application of customized drilling fluid formulation that contained high-performance shale stabilizers with the redesigned mud-weight schedules and early fluid displacement resulted in significant enhancements in tripping while drilling as well as in running and cementing the 13⅜-in casing.
Technical Training Assessment – a Tool to Upgrade Competencies in an Upstream Oil & Gas Company
Authors: Al-Daihani Eisa Hadi , Nandi Arun Kumar , Raza Syed , Varshney Avinash 
Published: September 2015

Abstract
Measuring technical training effectiveness is an enormous challenge worldwide. It is difficult to create a common model or tool kit to measure and determine the efficiency and return on training investment. Therefore, many organizations have developed their own unique customized assessment system to meet their needs.
In most of the Upstream Oil & Gas Companies, this task is outsourced. Generally, the assessment tool kits available to determine the training efficiency are based on only one or two elements i.e. participant's feedback or instructor's feedback which does not reflect clear picture and transparency of all activities of the event and eventually it has direct impact on knowledge gaps and desired competencies.
The present paper has come out with a model where four different key success elements are identified and measured through 4 dimensions (Participants, in-house Assessors, Instructors and QA team). Reasonable weightage are given to each element i.e. Planning, Training Providers' effort, Participants' effort and Environment. The final efficiency results is then compared with knowledge Gaps filled (Post-Pre). If the efficiency and gaps filled are in same swing OR close to each other, then it is considered as accurate and representative assessment. This ensures a more accurate and transparent process.
Additionally, the summary of Learning Objectives Achievements are thoroughly analysed and communicated the existing gaps to concerned members to ensure that they are filled with other resources (coaching or OJTs). Also the outcome of the assessment is shared with concerned training providers to address the issues eliminate these shortfalls in future training events for better efficiency and effectiveness.
Successful Application of Plug and Hydrajetting Technique during Multistage Fracture for Horizontal Wells with CT
Authors: Ortiz Jose Ramon , Montes Efrén , Hernandez Miguel , Castillo Hazael Abner , Carbone Salvatore 
Published: September 2015

Abstract
This paper presents an alternative for operators regarding tools and methods using coiled tubing (CT) during the implementation of horizontal completions.
To help address challenges faced developing horizontal completions, both cemented liners and open holes have been widely used in conventional and unconventional reservoirs. Various completion techniques have evolved from traditional tubing conveyed perforation (TCP) and plug setting, and hydrajet assisted fracturing has become the preferred pumpdown technique within the last six years in northern Mexico.
The criteria used to determine the completion technique is based on three parameters—extension of horizontal length developed [well geometry, dogleg severity (DLS), deviation], fracture design (pump rate, number of intervals) and type of reservoir being exploited. For the case discussed, a pumpdown technique was selected.
Pumpdown techniques are considered one of the fastest completion techniques to provide mechanical isolation between fracture stages; nevertheless, it has not been completely effective during all stages. Some of these techniques can cause premature setting of bridge plugs because of poor sand displacement or adverse well geometries, including high DLS. During the application of this technique, CT interventions are primarily considered in the event of contingencies, such as screenouts (sand cleanout) and plugs prematurely setting (plug millouts).
Even though no completion operation is immune to contingencies and associated costs and nonproductive time (NPT), a constant repetition of them because of inherent well conditions or poor fluid admission by the formation increases associated completion costs and diminishes equipment efficiency in place (frac set, logging unit).
As a result, CT has become an effective solution with the development of new tools and techniques to avoid such contingencies. This paper develops the concept “plugging and jetting,” wherein a mechanical isolation bridge plug (BP) is placed with CT, allowing abrasive perforations to help the producing formation communicate with the wellbore in a single run, thus allowing reduction of NPT up to 30% and providing a new alternative for horizontal completions.
This paper presents case histories with benefits and results. Bottomhole assembly (BHA) design considerations with improvements that provide a new alternative to operators are also presented. This method allows completion of fracturing stages in a continuous manner, thus being advantageous in terms of operational time reduction and consequently cost savings.
Correlation of Rock Mechanic Properties with Wireline Log Porosities through Fulla Oilfield - Mugllad Basin -Sudan
Authors: khair Elham Mohammed , Zhang Shicheng , Abdelrahman Ibrahim Mustafa 
Published: September 2015

Abstract
The current study presents elastic properties model for Fulla Oilfield in northeast of Block 6 in south of Sudan. Due to the poor formation consolidation and relatively viscose fluid, reservoirs may predictably produce massive amounts of sand and numerous troubles were found in the field as a result of sanding. No documented researches were found to introduce good parameters for rock strength and rock failure conditions through the field. Therefore, an accurate technique for predicting rock failure conditions may yield good profits and improve the economic returns through preventing sand production from the formations.
General correlations were presented to accurately describe rock strength parameters for the field; the work utilizes the application of the wireline porosities to be used as a strength indicator through the combination of rock mechanical theories with the characterization of Fulla oilfield. Log porosities (density, sonic and neutron) were calibrated with the core measured porosity, and the best matching porosity were correlated with the dynamic calibrated strength parameters by different correlations.
The results support the evidence of the use of porosity as an index for mechanical properties; power functions were found more reliable than the exponential functions, and can be used with a high degree of confidence; also it is more accurate than the Shale Index model presented in pre-vious work for same field; however, the result does not support the direct linear expression pre-sented in the literature for other field due to the variations in the field conditions.
Structural, Stratigraphic Geology and Pressure Compartmentalization of Feradus Field Based on 3-D Seismic Data and Subsurface Geology
Authors: Mira A.. , Meshref W.. , Radwan Amr M. , Mostafa A.. , Rayan A.. , Hassanin M.. , Saad A.. 
Published: September 2015

Abstract
Field development plan is an integration among Geophysical, Geological, Petrophysical and Reservoir Engineering data.
The 3D seismic and wellbore data confirm that the field is composed of complex structures with variable of oil-water contact and differences in pressure surveys.
A major source of these variations is compartmentalization, which is defined as limitation on the ability to produce hydrocarbons resulting from permeability barriers within a field. Two primary causes of compartmentalization. These are Stratigraphic and Structural variations in permeability.
Ferdaus field is located in East Abu Gharadig basin in Western Desert, Egypt. It produces oil from Cretaceous sandstones mainly from three reservoirs: Middle, Lower Abu Roash “G” (A/R “G”) members and Upper Bahariya Formation.
In Ferdaus field, Middle and Lower Abu Roash “G” members were deposited as barrier bars according to which the effects of the lateral and vertical sand facies changes within the productive sand intervals, have very limited impact on the pore connectivity based on Electric logs and mud log data. Therefore; the stratigraphic variations were neglected..
Structural compartmentalization, fault properties can constrain the fluid flow and pressure development, thus affecting decisions associated with the selection of the drainage strategy within reservoir management activities in order to maintain the pressure and increase the oil production rate.
By using 3D seismic data, electric logs and pressure data made it possible to sudivide the field into compartments which differ in number based on the reservoir level. This gave good estimates for the Original Oil In Place (OOIP) and reserves which leads to apply a good development plan by infill wells and/or increasing the productivity by applying secondary recovery project (water injection).
Branded entertainment: los contenidos de entretenimiento como herramienta de comunicación de marketing. Un estudio de su situación actual en España
Authors: De Aguilera Moyano Joaquín , Baños González Miguel , Ramírez Perdiguero Francisco Javier 
Published: September 2015

En el nuevo contexto de marketing surgen herramientas de comunicación como el branded entertainment; un tipo de mensaje híbrido con elque las marcas producen contenidos de entretenimiento. Metodología: Este estudio tiene como objetivo mejorar el conocimiento del branded entertainment y su situación en España así como sus expectativas de futuro. Se ha realizado una investigación exploratoria utilizando como técnica metodológica la entrevista en profundidad aplicada a un grupo de expertos en creación y distribución de branded entertainment. Resultados y conclusiones: Los resultados muestran: existe un amplio conocimiento de sus posibilidades como técnica de comunicación comercial; los contenidos producidos deben ser relevantes para competir con otros productos de entretenimiento; se espera un notable incremento en su utilización ante la pérdida de eficacia de las tácticas intrusivas; y se percibe como la herramienta de comunicación más adecuada para generar engagement del consumidor.
Effect of Geometric Conservation Law on Improving Spatial Accuracy for Finite Difference Schemes on Two-Dimensional Nonsmooth Grids
Authors: Mao Meiliang , Zhu Huajun , Deng Xiaogang , Min Yaobing , Liu Huayong 
Published: September 2015

AbstractIt is well known that grid discontinuities have significant impact on the performance of finite difference schemes (FDSs). The geometric conservation law (GCL) is very important for FDSs on reducing numerical oscillations and ensuring free-stream preservation in curvilinear coordinate system. It is not quite clear how GCL works in finite difference method and how GCL errors affect spatial discretization errors especially in nonsmooth grids. In this paper, a method is developed to analyze the impact of grid discontinuities on the GCL errors and spatial discretization errors. A violation of GCL cause GCL errors which depend on grid smoothness, grid metrics method and finite difference operators. As a result there are more source terms in spatial discretization errors. The analysis shows that the spatial discretization accuracy on non-sufficiently smooth grids is determined by the discontinuity order of grids and can approach one higher order by following GCL. For sufficiently smooth grids, the spatial discretization accuracy is determined by the order of FDSs and FDSs satisfying the GCL can obtain smaller spatial discretization errors. Numerical tests have been done by the second-order and fourth-order FDSs to verify the theoretical results.
Grensarbeiders en het recht op werkloosheidsuitkeringen: de zaak Mertens
Authors: Niesten H. 
Published: September 2015

Het Hof van Justitie van de Europese Unie heeft in het arrest Mertens geoordeeld dat een grensarbeider die in directe aansluiting op een voltijds arbeidscontract deeltijds werkzaam wordt bij een andere onderneming in dezelfde lidstaat gedeeltelijk werkloos is. Een situatie van volledige werkloosheid is slechts aan de orde indien de betrokken werknemer volledig heeft opgehouden te werken.HvJ 5 februari 2015, C-655/13, Mertens, ECLI:EU:C:2015:62
Uitsluiting van homoseksuele mannen als bloeddonor: het arrest Léger en de Nederlandse praktijk
Authors: Dute J.C.J. , Swarte A. 
Published: September 2015

Verschillende lidstaten, waaronder Nederland en Frankrijk, sluiten mannen die seksueel contact hebben (gehad) met mannen levenslang uit als bloeddonor. Het Hof van Justitie heeft zich op 29 april 2015 uitgesproken over deze permanente uitsluiting van MSM en heeft voorwaarden geformuleerd waaraan in dat geval moet zijn voldaan.HvJ 29 april 2015, zaak C-528/13, Geoffrey Léger/Ministre des Affaires sociales, de la Santé et des Droits des femmes, en Établissement français du sang, ECLI:EU:C:2015:288
Chapter 4. The places of Franz Josef Land: current visits and imagery
Authors: Umbreit Andreas 
Published: September 2015

Recent tourist cruises of Franz Josef Land have offered the chance to search for the remains of historic expeditions to the islands, as well as expeditions that used the islands as a base from which to try to reach the geographic North Pole. Expedition leader Andreas Umbreit discusses his recent such finds at both Greely Island and Teplitz Bay on Rudolf Island, as well as several other sites.
Losing your edge: climate change and the conservation value of range‐edge populations
Authors: Rehm Evan M. , Olivas Paulo , Stroud James , Feeley Kenneth J. 
Published: September 2015

AbstractPopulations occurring at species' range edges can be locally adapted to unique environmental conditions. From a species' perspective, range‐edge environments generally have higher severity and frequency of extreme climatic events relative to the range core. Under future climates, extreme climatic events are predicted to become increasingly important in defining species' distributions. Therefore, range‐edge genotypes that are better adapted to extreme climates relative to core populations may be essential to species' persistence during periods of rapid climate change. We use relatively simple conceptual models to highlight the importance of locally adapted range‐edge populations (leading and trailing edges) for determining the ability of species to persist under future climates. Using trees as an example, we show how locally adapted populations at species' range edges may expand under future climate change and become more common relative to range‐core populations. We also highlight how large‐scale habitat destruction occurring in some geographic areas where many species range edge converge, such as biome boundaries and ecotones (e.g., the arc of deforestation along the rainforest‐cerrado ecotone in the southern Amazonia), can have major implications for global biodiversity. As climate changes, range‐edge populations will play key roles in helping species to maintain or expand their geographic distributions. The loss of these locally adapted range‐edge populations through anthropogenic disturbance is therefore hypothesized to reduce the ability of species to persist in the face of rapid future climate change.
An evaluation of the Standardized Precipitation Index for assessing inter‐annual rice yield variability in the Ganges–Brahmaputra–Meghna region
Authors: Kattelus Mirja , Salmivaara Aura , Mellin Ilkka , Varis Olli , Kummu Matti 
Published: September 2015

ABSTRACTClimate variability has major impacts on crop yields and food production in South Asia. The spatial differences of the impact are not, however, well understood. In this study, we thus aim to analyse the spatio‐temporal relationship between precipitation and rice yields in the Ganges–Brahmaputra–Meghna region. The effects of rainfall variation on yields were analysed with regression models using the Standardized Precipitation Index (SPI) as an explanatory variable. Our results indicate that in large part of the study region, a strong relationship between precipitation and rice yields exists and the SPI at various lags chosen as the predictor variable performed well in describing the inter‐annual yield variability. However, the study demonstrated large spatial variations in the strength of this relationship or optionally in the suitability of the chosen methodology for investigating it. In the mid‐plains of the Ganges, which represent very important agricultural areas, precipitation variability has a strong impact on rice yields, while in downstream Ganges as well as in Brahmaputra, where precipitation is more abundant, the relationship was less pronounced. Where the performance of the regression models was weaker, it is likely that yield variation depended on other factors such as management practices or on other climate factors such as temperature. The results further showed that the SPI at 1, 3, 6 and 12 month lags calculated for the monsoon time (June–October) are most commonly the best at explaining the rice yield variability. The SPI can thus be considered a very useful predictor of rice yield variability in some parts of the study region, demonstrating that they could be used for agricultural applications and policy decisions to improve the region's food security.