bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tożsamość etniczna społeczności ar-Rūsīja w świetle pochodzenia ich kultowych posągów i sposobu ich rozmieszczenia w miejscu kultu
Authors: Michalski Michał 
Published: September 2015

Źródła arabskie zawierające informacje o społeczności określanej jako ar-Rūs odgrywają istotną rolę w sporze między normanistami i antynormanistami. Informacje przekazane przez arabskich podróżników oraz historyków dostarczają nie tylko lakonicznych wzmianek o ludzie noszącym taką nazwę, lecz dodatkowo zawierają cenne i obszerne charakterystyki obyczajów, stosunków społecznych oraz religii. Pozwalają zatem uzyskać różnorodne dane dotyczące czynników składających się na tożsamość tego wczesnośredniowiecznego ludu. Nie dziwi zatem, że arabskie dane dotyczące ludu ar-Rūs interesują zarówno historyków Słowian, jak również archeologów czy etnologów. W niniejszym artykule poddano rozważaniom materiał pochodzący z relacji z podróży do Bułgarów kamskich Ahmada ibn Fadlāna (1. poł. X wieku) w celu odpowiedzi na pytanie o to, z kulturą jakiego ludu można wiązać obyczaje oraz formy kultu Rusów.
Grecy we Lwowie: zapomniani obywatele
Authors: Lylo Ihor 
Published: September 2015

Lwów będący ważnym centrum życia ekonomicznego na pograniczu polsko-ukraińskim daje doskonałą okazję do badań nad historią małych grup etnicznych mieszkających na tym terenie od czasów wczesnego średniowiecza. O Grekach jako zwartej grupie, posiadających własną tożsamość etniczną, a mieszkających na stałe we Lwowie, możemy mówić od drugiej połowy XVI wieku. Chociaż przybywali tutaj już po upadku Konstantynopola w 1453 roku, to przez długi czas jako chrześcijanie prawosławni zmuszeni byli wybierać między utratą tożsamości religijnej a przyłączeniem się do grona prawosławnych Rusinów. Zróżnicowanie Greków mieszkających we Lwowie w XVI i XVII wieku – poddanej analizie w niniejszym artykule – odzwierciedla aktywność tej grupy, wśród której wyróżnić można kupców, przyjeżdżających czasowo, kupców posiadających stałe placówki, nauczycieli, rzemieślników i innych.
The “Arab Spring” and the Christian Linguistic Minorities in Syria
Authors: Bednarowicz Sebastian 
Published: September 2015

Syria has a heterogeneous population. It reflects the complicated history of the region and constitutes evidence for many migratory waves, that have been coming to Syria for centuries.The linguistic situation of Syria is less complicated, however also here the heterogeneity is observable. The official language of Syria is Modern Standard Arabic. Nevertheless, because of the diglossia being a common state in Arab countries, this language has no use in a daily communication. This role is performed by vernacular dialects of Arabic. In western Syria are spoken the Levantine and in al-Jazira the Mesopotamian dialects. The Kurds usually speak Kurmanji, which belongs to the Iranian languages. Moreover other small linguistic communities (e.g. Adyghe, Kabardian, Turkish) exist. As far as the Christian non-Arab linguistic minorities are concerned, in 2011 it was possible to indicate speakers of four main languages: Western Aramaic, Suret, Turoyo, Armenian.
A Pragmatic Approach To Understanding Liquid Loading in Gas Wells
Authors: Riza M. F. , Hasan A. R. , Kabir C. S. 
Published: September 2015

Summary
Liquid loading is the inability of a producing gas well to remove its coproduced liquids from the wellbore. The liquid flowing as droplets or film accumulates at the well bottom, thereby imposing backpressure at the sandface and triggering increasingly higher pressure loss in the wellbore. The problem initiated by liquid loading is manifested in terms of loss in well deliverability, causing the wellhead pressure to decline significantly, which, in turn, leads to the cessation of gas production. Accordingly, the liquid-loading issue reduces the ultimate recovery of a gas well.
Both the droplet-flow reversal and liquid-film-flow reversal have been postulated to be the underlying mechanism for liquid loading. Both mechanisms are predominantly premised on diagnosing the problem at the wellhead-flow conditions. This study explores the deliquefication issue in a gas well by fluid- and heat-flow modeling of the entire wellbore for a variety of flow situations in gas and gas/condensate reservoirs.
We observed that when a well experiences annular two-phase flow throughout the wellbore, no liquid loading occurs. The transition from annular flow to churn or slug flow initiates the liquid-film-flow or droplet-flow reversal, thereby triggering liquid loading. Most often, the flow condition at the well bottom controls the onset of liquid loading. By use of three published data sets, we show that the understanding of liquid loading improves when the entire wellbore-flow modeling is used. Forward modeling suggests that the tubing inside diameter and the well productivity index are the most important independent variables in determining the critical liquid-loading rate and the onset of liquid loading.
Road to Success and Lessons Learned in Intelligent Completion Installations at the Santos Basin Pre-salt Cluster
Authors: Schnitzler E. , Silva Filho D. A. , Marques F. H. , Delbim F. K. , Vello K. L. , Goncalez L. F. , Fonseca T. C. 
Published: September 2015

Abstract
This paper presents information regarding the installation of Intelligent Well Completions in Lula and Sapinhoá fields, at the Santos Basin Pre-salt Cluster. The technology is intended to improve reservoir management capability by using remote operated flow control valves and real time pressure and temperature monitoring for each perforated interval, which corresponds to different reservoir zones.
The benefits are obtained at the expense of additional challenges for well engineering, since well completion design becomes more complex and overall associated risks increase. Detailed and integrated planning is essential for the success of the operations, starting at the earliest phases of the well design and continued through detailed execution plans. The project team considered integration between downhole, subsea and topside systems as one of the main concerns during different planning phases.
First intelligent completion installations have been successful in pre-salt area, with no compromise to projects timeline or to the system performance. Applying the best practices learned during initial installations has been a key factor to achieve even better results in the following wells. Approximately 25 wells have been equipped with intelligent completions in Santos basin pre-salt area. Significant increase in performance and implementation time has been observed as a considerable amount of improvements have been made on system design and installations procedures.
Mechanistic Prediction of Oil-Water, Two-Phase Flow in Horizontal or Near-Horizontal Pipes for a Wide Range of Oil Viscosities
Authors: Li Liwei , Popa Florentina , Houchens Brent C. 
Published: September 2015

Abstract
The prediction of flow patterns transition is performed for oil-water, two-phase flows over a wide range of oil viscosities. Theoretical models of oil-water systems are studied in horizontal and near-horizontal pipe flows. The equilibrium flow pattern is dependent on the oil and water properties, pipe parameters, and flow rates. Four flow patterns are considered in the mechanistic model, including stratified (ST), core-annular (CA), oil-in-water (O/W), and water-in-oil dispersions (W/O). A mechanistic criterion, proposed by Zhang and Sarica (2006) for the same purpose, is used to identify stratified flow. The Brinkman (1952) model is used to distinguish the phase inversion of oil-in-water from water-in-oil emulsions. Boundaries of core-annular flow are based on the critical core diameter given by Brauner (2003). Comparisons between the mechanistic model predictions and published experimental measurements show good agreement in regime identification.
The importance of regime identification for correct pressure drop predictions is demonstrated by comparing the mechanistic model with a simple mixture model. The values of pressure drop predicted by both models are calculated and compared to existing experimental data. The mechanistic model shows significant improvement in pressure drop predictions.
Dimensionless groups from Buckingham Pi theory are used to investigate the sensitivity to the input parameters. The use of dimensionless groups reduces the number of dependencies from nine input parameters to six dimensionless groups. This reduces the complexity in the optimum design of pipeline systems. From most to least sensitive, for ranges typical of pipeline flow and fluids, the pressure drop prediction depends on the superficial Reynolds number of oil, Eotvos number, pipe inclination angle, superficial velocity ratio, density ratio, and viscosity ratio.
Probabilistic Bullheading Analysis is a Unique Risk Assessment Tool for Drilling and Completion Equipment Selection for Critical HP/HT Wells
Authors: Haghshenas A. , Cuthbert A. J. 
Published: September 2015

Abstract
This paper discusses the development and validation of the application of probabilistic bullheading analysis. Bullheading is the process of pumping fluid from the surface to the bottom of the wellbore in an attempt to deliver suitably weighted fluid to force fluid or gas from a given formation back into the formation. The methodology and procedure described in this paper provide a quantitative basis for risk analysis and equipment selection for high-profile wells, with focus on high-pressure/high-temperature (HP/HT) subsea well developments. As a result of this methodology, an accurate and risk-based approach can be taken using a probabilistic distribution of risks and pressure involved during bullheading operations.
The probabilistic model for performing bullheading analysis is based on the Monte Carlo method using statistical distribution of the parameters, which include reservoir properties, reservoir fluid properties, wellbore structure, and bullheading fluid properties. Each bullheading simulation assumes the wellbore is filled with the formation fluid and determines the shut-in pressure. Then, bullheading simulation considers the changes in pressure-volume-temperature (PVT) properties, fluid loss into the formation, fracture initiation, and compressibility of the fluids. Each probabilistic simulation run performs 2,000 simulations. The shut-in pressure and maximum pumping pressures are recorded to provide probabilistic distributions for risk-based analysis.
The application of the methodology is demonstrated using an example case study. A special emphasis is placed on performing a quality check of the statistical data to mitigate any skewedness that might occur during the simulations. A total of 24,000 simulations were performed to provide the distribution of pressure during the bullheading operation. The results can be presented in a variety of plots, including maximum bullheading pressures, maximum shut-in pressures, probability of fracturing, and the effect of pressure depletion.
Material Supply Challenges in the Offshore Project Environment
Authors: Kendig Bryan 
Published: September 2015

Abstract
This paper highlights challenges to material supply delivery schedules confronting the offshore major project sector. Topics are addressed to illustrate challenges with respect to: specification of equipment (clarity and timing), defining equipment packages, vendor risk assessment, quality control within the supply chain, and identifying the right personnel and workload planning for managing equipment fabrication. Experience-based recommendations are provided in order that organizations may mitigate these challenges on future major projects. The examples provided are based on the FPSO industry, but the challenges and the recommendations equally apply to other offshore structures, including Spars, TLPs, and semi-submersible platforms.
Method to Create Multiple Collocated Hydraulic Fractures Using a Temporary Localized Change in Stress Anisotropy Produced During an Initial Stimulation Treatment
Authors: Lewis Bryan J. , Surjaatmadja Jim B. 
Published: September 2015

Abstract
During a hydraulic fracturing stimulation treatment, transient geomechanics forces are exerted on the formation which modify the stress landscape near the wellbore and fracture planes. In regions where the horizontal stress anisotropy is less than 25%, there is a possibility for a temporary reversal in the minimum stress direction. During this brief window, a secondary hydraulic fracture can be created in a completely different direction, thus providing direct connectivity to previously unattainable locations in the formation.
This paper presents a computational validation of the multioriented hydraulic fracturing (MOHF) process. As traditional hydraulic fracture simulations are derived using static formation properties and steady-state assumptions of the formation behavior, a unique transient 3D computational geomechanic fracture simulator was developed to perform this study. The new model incorporates cohesive zone elements to represent the fracture plane, and captures the dynamics of the fracture initiation and propagation, as well as the transient stress modification in the formation. A realistic 3D fracture transient behavior is accounted for by the inclusion of multiple rock layers in the model, which are connected through energy absorbing frictional elements.
The simulations provide time sensitive operational recommendations for performing the MOHF stimulation to achieve maximum production increase from the well. Time lapse stress fields show vivid windows of opportunity where new fractures can be influenced to extend in alternate directions, hence offering formation drainage not attainable using conventional stimulation approaches. Production levels of twice to five times were predicted using reliable production simulators.
This new stimulation method enhances the state-of-the-art in hydraulic fracturing by requiring an understanding of the transient geomechanic response in the treatment area. As a time dependent method, this approach opens a new window of opportunity—both in conventional and unconventional plays—by providing connectivity to previously unattainable locations in the formation. Unfortunately, it also brings new complications. Industry standard fracture simulation technology becomes incomplete, as most models neglect the transient response of the system. Additionally, the availability of data related to the dynamic behavior of rocks is limited. The dynamic compression of the rock, slip characteristics between rock layers, and the amount of energy stored within slip planes—all recorded as a function of time—are particularly important when considering an MOHF process. Additional testing must be performed to obtain these data.
Completion Optimization Provides Step Changes in Horizontal Well Performance in the Nuiqsut Formation – An Oooguruk Field (Alaska) Case History
Authors: Bond Andy , Jasser Rami , Johnson Vern , Morgan Mike , Martin Mike , Palisch Terry , Williams Brock 
Published: September 2015

Abstract
The Oooguruk Unit is located on a man-made gravel island in the Beaufort Sea, five miles offshore the Alaskan North Slope in Harrison Bay. The field produces from the Kuparuk, Torok and Nuiqsut reservoirs. The focus of this paper is the Nuiqsut sandstone which is currently undergoing water and lean gas injection for secondary recovery. The wells are completed as 6,000 ft to 7,000 ft horizontal laterals aligned parallel with the preferred fracture orientation in a line drive waterflood pattern. Recent optimizations in mechanical diversion fracturing in these laterals have provided significant improvements in production rates including several recent wells with initial production of over 7,000 BOPD. This paper will document the completion and fracturing design evolution over several vintages of wells, as well as the use of pre-installed tracer systems to verify production uniformity and diversion success.
The reservoir ranges in thickness from 60 ft to 120 ft and is divided into several producing sand and shale intervals. The initial completion type planned for this reservoir was an 8,000 ft long undulating open hole horizontal lateral. This was quickly abandoned after the first well collapsed in a shale section. Undulated wellbores continued to be drilled for producing wells but were completed with pre-perforated pups spaced evenly throughout the liner in the horizontal section. These wells were stimulated with dynamic diversion fracturing treatments. Because of the logistical difficulties and expense in fracturing operations on a gravel island in the Beaufort Sea, two wells were also completed as multi-laterals, but resulted in productivity similar to dynamic diversion fracturing in one well and significantly less in the second well.
The initial move to undulated horizontal wellbores utilizing dynamic diversion fracturing treatments resulted in production improvements of nearly 100% over unstimulated wells. This led to the use of mechanical diversion techniques implemented in relatively flat horizontal laterals. This completion-type allowed mechanical diversion fracturing treatments utilizing over three times the low density ceramic proppant and generated wells with initial production of over 7,000 BOPD (an additional 100% increase over dynamic diversion fracturing). All future producing wells are now planned to be completed with mechanical diversion equipment. The completion optimization evolution described in this paper will be useful to completion and development engineers of other conventional reservoirs, and the learnings are already being successfully applied to another nearby Alaskan North Slope development.
Key Engineering Highlights of Facilities and Equipment for Oil & Gas Production
Authors: Mirza Babar , Al-Kharqawi Fahad 
Published: September 2015

Abstract
The paper provides an insight into key engineering aspects of Kuwait Oil Company's existing projects, facilities and equipment both current and from nearly 30 years of projects development. It deals with engineering features of mainly process and mechanical equipment, both static and rotating besides others, used for collection, separation, desalting, heat transfer, chemical treatment, storage, transmission, pipelines and similar facilities utilized for upstream oil and gas production, both sweet and sour. Engineering highlights include certain technological developments, metallurgical aspects, few best practices and lessons learnt as well. Seven (7) case studies are included towards the end that show case some of the engineering aspects of facility equipment, lessons learned from their engineering and conclusions drawn that emphasise the need to focus on initial, preliminary engineering aspects of projects and could provide useful tips for oil and gas engineers and designers.
Formulation of a Transient Multi-Phase Thermal Compositional Wellbore Model and its Coupling with a Thermal Compositional Reservoir Simulator
Authors: Forouzanfar Fahim , Pires Adolfo P. , Reynolds Albert C. 
Published: September 2015

Abstract
In this paper, we develop the detailed formulation of a transient multi-phase thermal compositional wellbore model and couple it with a thermal compositional reservoir simulator. We consider the presence of at most three phases which are an aqueous phase (water with dissolved CO2), a hydrocarbon liquid phase and a hydrocarbon vapor phase. The volume of wellbore is divided into a set of 1-D control volume grids. The mass balance equations for all components and the total energy balance equation are discretized over the wellbore control volumes. The transient total momentum balance equation (along the wellbore) and the drift-flux model equations for gas-liquid and oil-water systems are discretized over a set of backward staggered grids with respect to the wellbore grids. Following the assumption that the hydrocarbon phases inside a wellbore control volume are in equilibrium, a set of constraint equations are introduced to enforce the equality of the fugacity of each component in both hydrocarbon phases. The solution algorithm for the wellbore model is similar to the one for a compositional reservoir simulator, where, the sets of simulation equations and unknowns are divided into the sets of primary and secondary equations and unknowns which are solved sequentially. The appearance and disappearance of the hydrocarbon phases follow the phase stability and two-phase flash calculations. The wellbore model is fully coupled with a reservoir simulator at the bottom of the well. The interaction of wellbore with reservoir is handled with definition of source terms in the mass and energy balance equations and is obtained from continuity of force, energy and mass fluxes across the reservoir/wellbore interface. The boundary conditions for the wellbore model depend on the well control which includes the specified pressure or production rate at wellhead. Within the computational results section, the validation of the wellbore model against the analytical solution for the shock tube problem is presented. Moreover, the coupled wellbore/reservoir simulator is used to model the drawdown and buildup tests of a well in a single-layer reservoir, and a relatively long period of production from a multi-layer volatile oil reservoir.
Review and Analysis of Zonal Isolation Effectiveness in Carbonate Reservoirs Using Multi-Stage Stimulation Systems
Authors: Nozaki M. , Burton R. C. , Furui K. , Zwarich N. R. 
Published: September 2015

Abstract
It is common practice to complete long carbonate intervals with multi-stage stimulation treatments especially in horizontal wells. Each zone tends to be mechanically isolated using cement or openhole packers and then acid stimulated. Zonal isolation effectiveness is judged on the basis of job pressure response or post-job production logging. The recent introduction of intelligent well systems (IWS) with zone specific pressure and temperature gauges allows more effective review of zonal isolation during stimulation.
This paper reviews zonal isolation results from a series of high-rate acid jobs conducted in wells equipped with zone-specific pressure and temperature gauges. 21 acid stimulation jobs from 13 different wells are reviewed to investigate the effectiveness of zonal isolation during and after treatment. Well examples presented in this paper cover several different completion types: cemented and un-cemented; intelligent well system, plug-and-perf completion and ball-activated sliding sleeve completion. The analysis revealed several different pressure and/or flow communication patterns. Field examples and analysis results presented in this work will help engineers design and optimize cemented and un-cemented wells requiring multi-stage stimulation in carbonate fields.