bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of New Horizontal Wells by the Use of Artificial Neural Network Algorithm
Authors: Ali Diyar H. , Al-Jawad Mohammed S. , Van Kirk Craig W. 
Published: March 2015

Abstract
It is an established fact that substantial amounts of oil usually remain in a reservoir after primary and secondary processes. Therefore; there is an ongoing effort to sweep that remaining oil. Field optimization includes many techniques. Horizontal wells are one of the most motivating factors for field optimization. The selection of new horizontal wells must be accompanied with the right selection of the well locations. However, modeling horizontal well locations by a trial and error method is a time consuming method. Therefore; a method of Artificial Neural Network (ANN) has been employed which helps to predict the optimum performance via proposed new wells locations by incorporating reservoir properties and production data of previous wells.
This study used the Artificial Neural Network (ANN) that has been programmed in a manner to predict the cumulative oil produced for a certain grid by providing the corresponding properties of the grid. The network has been validated with real data collected from a number of drilled hypothetical wells. Furthermore; the validated network used to simulate the field parts that have not been drilled yet, to predict the corresponding cumulative oil for each grid. Field-scale simulation has been carried out and new horizontal wells have been allocated using the validated prepared data by the Artificial Neural Network Algorithm and an approved Iraqi reservoir model. Finally, different optimization scenarios have been investigated on the overall field recovery performance.
Paradigm Shift in Egypt's Western Desert: Premium Grade Steel-Body Bits Displacing Matrix Designs in Key Applications
Authors: Kamel Osama , Mansour Mahmoud , Ibrahim Abdelshafy , Reyad Mahmoud , Hanafy Omar , Sherif Mohamed , Aguib Karim , El Sheikh Omar , Bits Smith 
Published: March 2015

Abstract
Recent manufacturing and hardfacing advances have produced a steel-body PDC bit (SB-PDC) capable of efficiently drilling interbedded formations at significant depth. These technological advances have increased the bit's resistance to abrasion/erosion and enabled a new style steel-body PDC bit to drill formations in Egypt's western desert previously drilled by matrix PDC bits. Field tests have confirmed the steel-body PDC bit can outperform matrix PDCs in a wide-range of interbedded applications that contain a heterogeneous mixture of shale, sand/siltstone, and limestone. The approach combines optimized cutting structure design and premium PDC cutters that enable the steel-body PDC bit to drill the abrasive sand/siltstone component. The bit can also efficiently drill shale and soft limestone due to its hydraulic efficiency which was a factor limiting performance improvement in previous designs. The bit solution employs: ➣Cutting structure optimized using FEA-based modeling system➣Premium grade PDC cutters➣Next generation of abrasion/erosion resistant hardfacing material➣Hydraulically efficient bullet-shaped body type
The new SB-PDC technology was deployed in a sequence of tests in different applications and fields in Egypt's western desert. The trials were run in different lithologies at different depths. Direct comparisons to relevant matrix PDC technology and other available steel-body bits clearly demonstrates the new-style steel-body PDC bit's value by setting new benchmarks and reducing cost/ft.
Equalizing Well Pressure Drop with Swirl Chambers
Authors: Noui-Mehidi Mohamed N. 
Published: March 2015

Abstract
The present paper is concerned with a numerical study of swirl flows applied as a pressure equalization means in an inflow control devices (ICD) setup. The system discussed includes an isolated mechanical flow path that is designed as a conical channel through which the produced fluids are injected with a tangential inlet. The system forms a swirl chamber that generates a swirling flow that decays along the flow path. The active swirl part arrangement could be mounted in serial sections along the flow path to maintain the swirl properties of the flow over the desired distance. The swirl motion generates a pressure drop that is related to the length, gap width, and tangential inlet size of the swirl element. The present work presents a numerical investigation of this system by studying the primary flow variables using a finite difference method. The numerical results revealed the flow nature and the resulting pressure drops with regard to the flow system variables.
A Paradigm Change In Water Flood Strategy Using Horizontal Injectors In The Sabriyah Field, North Kuwait
Authors: Jamal Mariam Abdul-Raheem , Chetri Hom , Al-Towaitan Tasneem , Badusha Sayed Ibrahim , AL-Zaabi Hamad 
Published: March 2015

Abstract
As one of KOC's main Oil Production field's North Kuwait is developing projects and support activities to increase Oil production to one million bbl. /day by 2017-2018. A critical and vital part art of this Oil Production strategy are the major water injection projects. Based on last 10 years of water flood experiences, the water flooding strategy was modified to add horizontal injectors to help accelerate pressure maintenance to the critical pressure sink areas, in particular, and pressure support to the giant NK Sabiriyah Mauddud reservoir, in overall.
An example of this being Well SA-M HST1, a existing vertical injector, was chosen to be horizontally side tracked, the primary purpose being to improve and enhance the reservoir pressure in the Northern part of the field which historically in the past has exihibited decline in pressure due to a increased offtake. Preliminary results are positive and show a reduction in the reservoir pressure decline rate, Stabilization in ESP intake pressures at offtake wells & Reduction in the frequency of ESP trips.
To understand and analyse completely the response behavior, a comprehensive monitoring of SA – M HST1 injector has been initiated, covering several tarcking items such as Well head pressure readings, Flow line pressure readings, Gathering center water cuts tests, Water cut samples, Static bottom hole pressure for the closed wells in the pattern, Production logging for the injector and producers, Flowing bottom hole pressures and time lapsed portable tests. Monitoring has been planned for a period of six months to understand clearly the vertical pressure connectivity between the productive layers within the reservoir, and also more importantly the impact on the production behavior of the surrounding wells. The paper then closes and shares with the reader the lesson learnt and the next steps.
Offshore Pipeline Precommissioning Operations Using Coil Tubing Units
Authors: Mikhailov M. 
Published: March 2015

Abstract
Coil Tubing has been used in many oilfield applications worldwide both offshore and onshore, upstream and recently downstream.
Apart from upstream coil tubing applications such as workovers, well interventions, paraffin/scale removal, jetting, acidizing and coil fracturing, it is employed more and more actively for pipeline precommissioning operations subsea, especially dewatering. With a slight modification (there is no need for a BlowOut Prevention (BOP) System in this case) the coil tubing unit is positioned on a vessel's deck and connected to a high-pressure compressor spread injecting pressurized air down the coil tubing string to the hot stab connection of the pipeline to be dewatered. Pressure drops across the tubing string and other connections and flow patterns can be simulated using Baker Hughes' proprietary software CIRCA™. For deep water offshore applications high pressure boosters are often employed.
In-Line Water Separation: A New Promising Concept for Water Debottlenecking Close to the Wellhead
Authors: Abbad Mustapha , Dyer Steve , Ligneul Patrice , Badri Mohammed 
Published: March 2015

Abstract
This work presents a new technique which allows in-line water/oil separation directly from the pipeline and close to the wellhead. It enables an increase of the oil/water ratio in the pipeline and decreases the cost of water transportation and handling. The separation process relies on the detection of the water front level in an oil/water stratified flow in an inclined pipe. The main line has a T-junction connected to a control valve from which the water is extracted. The position of the water front is detected by a set of resistivity/capacitance probes and a proprietary feedback control algorithm which allows water extraction rate. The combination of the pipe inclination and the control system ensures that mostly oil is flowing in the main pipe and mostly water is flowing through the extraction T-junction. The concept has been studied theoretically, numerically and experimentally. A laboratory scale flow loop model was built and tested to validate this technique in a controlled environment. Then, it was upscaled into a field size prototype that captured the various specifications required for an efficient water/oil separation. The cleanness of the separated water is measured in the lab experiment as well as in the full-scale prototype using a fluorescence technique. The obtained results show that the extracted water rate might exceed 70% of the water initially measured at the inlet of the separator, and it contains less than 500 ppm of oil. The system is currently under consideration for field trial.
First Successfull Implementation Of High Temperature Video Camera to Identify Downhole Obstructions in Gas Wells: A Saudi Case
Authors: Mukhliss Amroo E. , Driweesh Saad M. , Sagr Abdulaziz M. , Bolarinwa Simeon , Wiltosz Mark 
Published: March 2015

Abstract
Video cameras have been used in the oil industry with high success rate reported by several operating companies around the world. However, High downhole temperatures especially in gas wells have always posed a limitation to the full utilization of the camera as a diagnostic tool. Previous trials with the camera were prematurely aborted as internally it tends to heat up quickly allowing no time to carry out the full diagnosis of the restriction. However since the camera has gone through extensive modifications and has been equipped with the necessary capabilities to withstand high downhole temperatures.
Picture resolution, re-fresh rate, LED intensity and tool rotation can be controlled at surface by the operator. Well deviation, high side and internal tool temperature are among the parameters displayed at E-line Cabinet on surface.
This paper documents a successful operational experience of the first HT run in Saudi Arabia using this type of downhole camera. E-Line High Temp camera was deployed in gas well in attempt to determine the cause of an unpassable obstruction. Several measures to diagnose the nature of this obstruction were attempted using series of gauge cutter runs but with no success. The High Temp camera was mobilized in an attempt to finally discover the severity and extent of this obstruction.
The operation using the downhole camera was carried out successfully achieving the desired objective of the intervention. The interpretation of the images indicated that the well had some kind of mineral build-up which looks to be solid in appearance indicating scale or cement materials.
Overcoming Environmental and Technical Challenges for Well Integrity—A Global Perspective
Authors: Johnson Carl R. , Shindgikar Nikhil Dilip , Beurel Muriel Martin 
Published: March 2015

Abstract
Globally, there is increasing focus on hydrocarbon recovery in regions that are new to environmental legislation and regulation; very often this is an offshore environment where well integrity has broad effects. Providing environmentally compliant fluids is standard, and thus expertise in regulations and “green” chemistry is rapidly being pulled from established regions such as the North Sea. The expectation that both regulations and the chemistry can be slotted into the new region's operations is difficult to achieve, as there is no single set or universal set of regulations; so no ‘one-size-fits-all’ solution.
This paper addresses numerous distinct challenges for cementing-related fluids and how the changing regulatory stage across different regions can be optimally managed. Indeed, as these regions can be “frontier” or remote in nature, emphasis on cost control from operators is high to minimize the well construction cost. This may not align with environmental compliance expectations. Particular examples, from West Africa, will be presented to highlight challenges toward conformity with the aim of discussing the pitfalls and potential solutions available.
Environmental regulations and practices are continually evolving, and come under increasing scrutiny at the well planning stage, with heavy emphasis on well integrity and cementing quality. The most legislated region of offshore E&P is the North Sea, and, naturally, governing bodies and operators are adopting North Sea regulatory models elsewhere. Through case histories covering North Sea, French Guiana, West Africa, the Arctic, Canada, and Australia, a systematic review of the numerous approaches governing the application of cementing fluids for well integrity will be deliberated. An innovative “green” chemistry solution for high-pressure/high-temperature (HP/HT) operations, developed to tackle compliance with Norwegian North Sea regulations, will act as key example of steps taken to safeguard global environmentally sensitive regions and ensure long-term well integrity.
Permian Frac Systems Using Produced Water
Authors: Kakadjian Sarkis , Thompson Joseph , Torres Robert , Pontifes Antonio , Rodriguez Amanda , Hamlat Yahia Ait 
Published: March 2015

Abstract
In areas where fresh water costs and produced water disposal costs become problematic, operators as well as service companies have shown the desire to use produced and flow back water in field operations to enhance the overall completions economics. This paper shows the experience of new Stabilized Crosslinked Fracturing fluid systems pumped in the Permian Basin (West Texas, United States) using borated produced water with levels of Total Dissolved Solids (TDS) exceeding 30,000 mg/L.
The new Frac fluid systems are developed for temperature ranges between 120-220 °F and designed to delay the crosslinking time when needed, utilizing the boron already present in the water. In addition to the technical success, the back end costs are significantly reduced by transporting produced and/or flowback water to locations for re-use rather than disposing them into well(s) located miles away. This unique Frac fluid systems approach, which conserves fresh water aquifers and recycles produced and flowback water, has broken the code for recycled water and reduced disposal costs significantly. The operators and the service company have pumped numerous stages using only sock filtration to decrease the level of suspended solids in the waste water. This paper reports laboratory testing and case history data.
Experimental Investigation of Three-Phase Immiscible Floods during Gas Gravity Drainage in Naturally Fractured Reservoirs
Authors: Netaifi A. S. , Cinar Y. 
Published: March 2015

Abstract
This paper presents results of a systematic laboratory study to investigate how three-phase immiscible flow can affect gravity-drainage gas injection in naturally fractured reservoirs. In the experiments, quasi two-dimensional glass-bead packs represented matrix and grooved glass strips the fractures. A three-phase hydrocarbon-water-alcohol system mimicked immiscible fluids. Conductive and isolated fractures were examined for two different flow rates. Continuous gas injection, water-alternate-gas and simultaneous water-alternate-gas injection schemes were run. A scaling analysis was conducted to quantify effects of viscous, capillary and gravity forces on the displacement performance for each experiment.
Experimental results show that displacements were controlled mainly by capillary forces. The comparison between injection schemes shows that the continuous gas injection scheme yields highest ultimate recovery. An injection efficiency factor is introduced to assess the feasibility of injection process, which demonstrates that the optimum injection occurs through the water-alternate-gas injection. This is because of the minimum gas consumption, the gas phase which improves the microscopic displacement efficiency in gravity-stabilised floods and the water phase that supports the macroscopic sweep efficiency by preventing the gas phase from fingering. It is found that the oil recovery and injection efficiency in the experiment with the isolated fracture are higher than in the experiment with the conductive fracture model.
Evidence for an Association Between Tako-Tsubo Cardiomyopathy and Bronchial Asthma: Retrospective Analysis in a Primary Care Hospital
Authors: Blotzheim Leonardo Glutz von , Christen Stefan , Wieser Stephan , Ulrich Silvia , Huber Lars C 
Published: March 2015

Objective:
We investigated the prevalence of bronchial asthma in patients with Tako-Tsubo Syndrome (TTS).

Design:
This retrospective case-series study was conducted in a primary care hospital in Zurich, Switzerland. Data of all patients with newly diagnosed TTS (2002 - 2012) were assessed electronically by the use of ICD-10. Asthma prevalence was compared to published epidemiologic data.

Setting:
Bronchial asthma is characterized by airway inflammation and, during attack, release of endogenous catecholamines. Sympathomimetic drugs are the mainstay of treatment for asthma patients. Likewise, catecholamine mediated diffuse microvascular myocardial dysfunction seems to be of critical importance for the development of TTS.

Results:
20 cases of TTS were identified. 90% were female, showed a median age of 70±13y [25y - 90y], an apical and/or midventricular ballooning pattern with preserved basal function and a median initial LVEF of 34±9% [25% - 55%]. 65% of patients underwent coronary angiography to rule out significant coronary artery disease. Hypertension was present in 45% of patients, 35% were smokers, none was suffering from diabetes. Prevalence of asthma in patients with TTS was significantly higher compared to the normal population (25% vs. 7%, p=0.012). In 30% of the TTS patients an iatrogenic cause for development of TTS was identified.

Conclusion:
Prevalence of asthma was significantly higher in patients with TTS compared to epidemiologic data from an age-matched population. Phenotypes of patients developing obstructive ventilatory disease and TTS might share common pathogenic mechanisms beyond the use of bronchodilatators. In addition, we identified other iatrogenic etiologies in patients with TTS.
Effect of Thermocycling, Degree of Conversion, and Cavity Configuration on the Bonding Effectiveness of All-in-One Adhesives
Authors: El-Damanhoury HM , Gaintantzopoulou M 
Published: March 2015

SUMMARY
The aim of this study was to compare five all-in-one bonding agents with respect to microleakage, microtensile bond strength (μTBS), degree of conversion (DC) and the impact of cavity configuration. The materials tested were Adper Easy Bond, Clearfil S3 Bond, iBond, Optibond All-in-One, Xeno IV, and Adper Single Bond Plus as a control. The DC of each adhesive was measured on the surfaces of dentin discs (n=5) by attenuated total reflectance Fourier transform infrared spectroscopy. One hundred and forty-four extracted human molars were randomly divided and assigned to one of the five tested adhesives and the control group. The μTBS to dentin was measured on flat occlusal dentin with and without thermocycling and to the gingival floor dentin of class II cavities (n=8). All specimens were restored with Filtek Z250 resin composite. Class II samples were immersed in a 5% methylene blue dye solution for 24 hours, and microleakage was examined under a stereomicroscope. Micromorphological analysis of demineralized/deproteinized specimens was done using scanning electron microscopy. The DC and microleakage data were statistically analyzed by one-way analysis of variance (ANOVA) and μTBS data by two-way ANOVA followed by a Bonferroni multiple comparison post hoc test (α=0.05) and Weibull-distribution survival analysis. The relation between different variables and μTBS and microleakage was tested by the Pearson correlation coefficient and regression statistics. A moderate direct relation between DC and μTBS durability was found for all the adhesives tested. Significant wide variations exist among the results obtained for single-bottle adhesives tested regarding their μTBS and microleakage. Some of the all-in-one materials tested have shown significantly inferior results under a high C-factor or after aging. The use of these materials should be carefully considered.
Elektriliini trasside puitse biomassi modelleerimine/ Modelling of woody biomass on electricity pylons
Authors: Mitt Risto , Padari Allar , Samsonov Marti 
Published: March 2015

Abstract
The aim of this study was to model regression equations for the volume of oven dry stems, branches and leaves/needles in relation to tree height and to estimate the growth of biomass on electricity pylons. A formula of linear regression between moisture and acidity of soil was also modeled in order to assess the volume of woody biomass. In 2009, 42 sample areas with 126 circular plots were created. The sample areas were located all over Estonia in order to render a wide representation of soil types. The plots were re-measured in 2012. The sample areas consisted of three circle plots divided into a series of 4m wide, distance between centers of circles was 10m. One hundred twenty two trees from the sample areas were felled in 2009 and 182 in 2012. The data of sample trees were analyzed and regression equations to estimate the growth of trees in sample areas were calculated. The average oven dry mass for stems and branches was 1970 kg/ha, with a maximum of 10,520 kg/ha. Leafless biomass growth was also calculated for each sample plot: the largest growth (in carbon soil) was 1562 kg/ha/y. The density of trees in the sample plots were the biggest influence on annual growth. The number of trees varied up to 200,000 with an average of 48,000 trees per hectare. The study also includes the results of research into the relationship between biomass production and soil properties.
Sorption ability of the soil and its impact on environmental contamination
Authors: Hřibová Šárka , Zlámalová Gargošová Helena , Vávrová Milada 
Published: March 2015

ABSTRACT
From the physical point of view, soil is a heterogenic polydisperse system. It often becomes a place of a secondary contamination during extinguishing uncontrolled areal fires in nature. Foam extinguishing agents (FEAs), used at these events, basically contain surface active substances and perfluorinated compounds. These tend to be captured in the soil matrix due to their specific properties. Contaminants could be partly flushed out with rainwater, which causes several times dilution of contamination and lower ecotoxic activity. However in the dry season, foam solution infiltrates into the bed soil without any dilution. This study deals with the direct influence of soil the sorption complex on ecotoxicity of five selected FEAs, i.e. Expyrol F 15, Finiflam F 15, Moussol APS F 15, Pyrocool B and Sthamex F 15. The substances tested were prepared in concentration of work solution and then applied on standard soil matrix LUFA 2.3. For experimental purposes, a column infiltration apparatus was designed and compiled. Filtrates were collected and then tested using the plant organisms Sinapis alba and Allium cepa L. The study compared ecotoxicologic effects of filtrates with an original work solution. Moussol APS F 15 seems to be the least ecotoxic of the FEAs tested. A direct influence of soil sorption complex onto ecotoxicity reduction was also established. This finding demonstrates the sorption ability of soil particles and ion exchange activity of the soil matrix. It is a positive finding for biota of aquatic environment, yet at the expense of those in soil