bluuebunny/crossref_metadata_2025_split huggingface dataset:
Innovative Permanent Down-Hole Scale and Corrosion Monitoring System Using Ultrasound Guided Waves Technology
Authors: Saeed Abubaker , Volker Arno , Martina Quincy , Alalouni Ahmed 
Published: October 2019

Abstract
Scale and corrosion affect the production certainty of oil and gas well. Scale build-up reduces flow and ultimately could shut down production when it block to tubing completely. Corrosion of the tubing wall occurs very often simultaneously with scale build-up and affects the integrity of the tubing wall. Vital information about the integrity is essential for safe operation and flow assurance. The objective of this research is to develop a scale and corrosion monitoring system based on ultrasonic guided waves. The innovative approach is based on transmitting axisymmetric ultrasound guided waves to a receiver array around the circumference of the pipe. Both torsional and longitudinal waves are used over a wide frequency range. These modes are sensitive to variations in tubing wall thickness, scale thickness and scale properties. Numerical simulations are used to investigate various scaling /corrosion scenarios and proof the concept theoretically. The simulations also provide the requirement for specially designed EMAT’s (ElectroMagnetic Acoustic Transducers), which are capable of withstanding downhole conditions, i.e., pressure and temperature. These transducers cover a wide frequency range, such that there will be several higher order modes present. This is required for accurate sizing. The used wave modes are only sensitive for changes in tubing wall thickness and scale build-up. The newly developed transducers are tested on a 4.5-inch tubing with artificial scale. During the experiment the artificial scale thickness is varied to evaluate the sizing accuracy. Experimental results demonstrate the capability of measuring the scale built-up from the outside with good accuracy.
From Ideation to Commercialization – Development of the First Real-Time Monitoring Device for Asphaltene Deposition
Authors: Abdallah Dalia , Punnapala Sameer , Al Daghar Khadija , Kulbrandstad Omar , Godoy Manuel , Lovell John , Madem Sai , Babakhani Aydin 
Published: October 2019

Abstract
Asphaltene deposition has been identified as one of the top flow assurance challenges in a number of onshore fields in Abu Dhabi with over 100 wells impacted. There was no device in the industry for direct measurement of asphaltene deposition, so the national oil company sponsored an R&D project to develop a sensor that could quantify the percentage of asphaltene in the flowing oil.
Current ways of identifying an asphaltene problem rely upon accessibility checks with slickline units and hence clean-up operations are reactive and are often too late. In order to detect the problem earlier, an asphaltene specific real-time sensor would be required. The sensor design selected built on the concept of Electron Paramagnetic Resonance (EPR), wherein free-radicals in the asphaltene are resonated by an external magnetic field. The EPR signal is directly proportional to the amount of asphaltene in the crude, with a signal drop indicating potential deposition upstream of the sensor.
By focusing on the asphaltene free-radical response, rather than looking for a broad range of molecules, it proved possible to miniaturize and ruggedize a device for oilfield applications. It remained important to prove that this modification did not casuse a loss of resolution. For the first field trial in these onshore fields, instead of having the device installed directly into one well, the system was tested off-line so that daily analysis from 15 different wells could be achieved and device resolution could be tested. The resolution proved to be better than 0.1%. Moreover, some wells showed nearly 5% variation from one day to the next while other wells showed barely 1% variation. The wells with the higher standard deviation were those which had historically seen more asphaltene problems. Results from these 15 wells exceeded expectations, so a decision was taken to launch a second field trial with the device now able to be mounted inline at the wellhead for real-time continuous monitoring. It is anticipated that the application of this system will help plan clean-up jobs before a well gets totally plugged. This should lead to substantial cost savings in addition to minimizing well downtime and loss of production.
This paper presents a novel solution that was developed from inception or "ideation" all the way to commercialization through a research collaboration between a national oil company, a university and a start-up technology provider. The outcome is an industrial Internet of Things (IoT) real-time monitoring device, the first of its kind, that detects asphaltene deposition and makes it possible to optimize chemical programs by incorporating surface data into an integrated flow assurance management system.
Proxy Model Based on Artificial Intelligence Technique for History Matching - Application to Brugge Field
Authors: Bruyelle Jérémie , Guérillot Dominique 
Published: October 2019

Abstract
History matching of production data is a process requiring a large number of reservoir simulations that are huge time-consuming. To reduce the computation time, an approach consists of using a meta-model to replace the reservoir simulator. In this paper, a proxy model based on an artificial intelligence technique (artificial neural network) is evaluated and compared to proxy models conventionally used for history matching such as polynomials or kriging methods. The proposed approach provides accurate prediction results to speed up and improve the history matching process. An application to the Brugge field is presented.
Trapped Oil in Low-Permeability Zone Unswept by Water Flooding Under Permeability Heterogeneity Can be Mobilized by Ultra-Low Interfacial Tension: EOR Mechanism of Dilute Surfactant Flooding Proved by Low field NMR Core Flooding and Two-Parallel Core Flooding Experiments
Authors: Yuan Chengdong , Pu Wanfen , Varfolomeev Mikhail A. , Tan Tao , Zhao Shuai 
Published: October 2019

Abstract
It is a well-known EOR mechanism that residual oil in swept zone after water flooding (including oil drops, films and clusters) can be mobilized by low interfacial tension (IFT) during surfactant flooding. The aim of this work is to investigate if trapped oil in low-permeability zone (unswept by water flooding) can be mobilized or not by ultra-low IFT in dilute surfactant flooding without any additional conformance control treatment using polymer, gel, or foam, etc. Anionic–nonionic surfactant was used to attain ultra-low oil-water IFT of 10-4 mN/m at a low surfactant concentration of 0.2wt% under high salinity without adding any additional solubilizer, alkali, alcohols, etc. Using this surfactant solution, low field NMR core flooding experiment was conducted using heterogenous core. This core was drilled from artificial rectangular-sandstone core with two layers (gas permeability in low- and high-permeability layer is 90mD and 1200mD, respectively). Then, two-parallel core flooding experiment was conducted, where two core holders were parallelly installed (one for low-permeability core, one for high-permeability core) to simulate the heterogenous permeability condition.
NMR core flooding results showed that the reduction percentage of oil saturation in large pores (mostly distributed in high-permeability layer) was much higher than that in small pores (mostly distributed in low-permeability layer) during water flooding. After a high water cut of 98%, surfactant was injected. It was found that oil saturation in both high- and low-permeability layer was decreased, and the reduction percentage in small pores was much higher than that in large pores, which partly indicates that ultra-low IFT cannot only mobilize residual oil in swept zone in high-permeability layer, but also effectively mobilize trapped oil in unswept zone in low-permeability layer. This EOR mechanism was further verified by two-parallel core flooding experiment. Under the permeability max-min ratio of 705.1 to 48.96 mD (water permeability), there was no oil production from low-permeability core during water flooding even when water cut was 98% in high-permeability core. This means that it is difficult for injected water to penetrate into low-permeability core under such a heterogeneity. However, when changed to surfactant flooding, low-permeability core started to produce oil. A surfactant injection of 0.3 PV can yield an oil recovery of about 5% and 16% from low- and high-permeability core, respectively, which proves that ultra-low IFT has ability to mobilize trapped oil in low-permeability zone unswept by water flooding under heterogenous permeability without any additional conformance control treatment.
A Comprehensive Overview of Early Implementation of Chemical Eor Sector Model for North Kuwait Sabriyah Lower Burgan Reservoir
Authors: Al-Ghnemi Mohammad , Ozkan Erdal , Kazemi Hossein , Al-Murayri Mohammed , Pitts Malcolm , Dean Elio 
Published: October 2019

Abstract
This study focuses on a multi-well pilot test for a chemical enhanced oil recovery (CEOR) project in Sabriyah Lower Burgan reservoir that is located in the north of Kuwait. The objective of this research is to evaluate the economic applicability of a proposed Alkaline Surfactant Polymer (ASP) formulation based on laboratory core flooding in a multi-well pattern of the candidate reservoir. Simulation and economic modelling was used for this evaluation. Sabriyah Lower Burgan is a large sandstone reservoir with excellent rock properties (Darcy permeabilities). The field is currently developed through primary depletion with an active edge water drive. All forms of EOR were evaluated and CEOR was the only practical technology that passed all screening criteria. Understanding the reservoir behavior is critical and evaluating multiple implementation strategies is important to insure economic success.
The objective of the pilot test is to demonstrate that the recommended ASP formulation can economically mobilize remaining oil (ROS) in Sabriyah Lower Burgan reservoir. The process to achieve this objective includes: Expand a small scale pilot into a large multi-well pilot.Evaluate different well pattern configurations using numerical simulation to demonstrate the effectiveness of CEOR in producing additional oil.Apply economics to all case studies to determine applicability and commerciality of the different proposed case studies.List observated key challenges associated with large scaled field implementation.
Including economics in a technical CEOR assessment will help understand practical aspects of field CEOR implementation for the Sabriyah Lower Burgan field.
Enhanced Oil Recovery for Carbonate Oil Reservoir by using Nano-Surfactant:Part I
Authors: Hammood Hajir A. , Alhuraishawy Ali K. , Hamied Ramzy S. , AL-Bazzaz Waleed Hussien 
Published: October 2019

Abstract
Worldwide, excellent efforts have been created to enhance the recovery of oil. Over the previous century, Nano technology features in EOR have been the focus of attention.The introduction of nanotechnology started in the late 1980s and was created by rearranging atoms and molecules to synthesize fresh nano-materials. Based on the small partice size of NPs' (1-100) nm, the nanomaterial's optical, thermal, chemical and structural properties differ completly from those shown by either its atoms or bulk materials. Nanoparticles and surfactants assist each other stabilize and maintain stable emulsions. Furthermore, it is clear that surfactants contribute to the stability of nanoparticles and emulsions in order to reduce IFT and change the rock wettability toward water.
The main objective of this study is to investigate the effects of nano particles and surfactant on interfacial tention, fluid stability, and wettability index of carbonate reservoirs. Two key parameters were examined: silica nano particles and silica nano particles with Sodium Dodecyl sulfate (SDS) as an anionic surfactant. Surface tension test was done for the surfactant to find critical micilles concentration, Interfatial tension test were done for fluids containing different SiO2 concentrations, dynamic light scattering (DLS) method was used to find the stability of nanoparticles in aqueous solution, and wettability test was done for core samples to investigate the effect of nano-surfactant on rock wettability. The results show that the CMC value for SDS was 0.158 wt% and increased SiO2 concentrations can reduce IFT values. Also, silica NPs' and SDS could improve the carbonate rock wettability to be more water-wet.
Isolating promoters from Corynebacterium ammoniagenes ATCC 6871 and application in CoA synthesis
Authors: Hou Yingshuo , Chen Siyu , Wang Jianjun , Liu Guizhen , Wu Sheng , Tao Yong 
Published: October 2019

Abstract
Background ： Corynebacterium ammoniagenes is an important industrial organism that is widely used to produce nucleotides and the potential for industrial production of coenzyme A by C. ammoniagenes ATCC 6871 has been shown. However, the yield of coenzyme A needs to be improved, and the available constitutive promoters are rather limited in this strain.
Results ： In this study, 20 putative DNA promoters derived from genes with high transcription levels and 6 promoters from molecular chaperone genes were identified. To evaluate the activity of each promoter, red fluorescence protein (RFP) was used as a reporter. We successfully isolated a range of promoters with different activity levels, and among these a fragment derived from the upstream sequence of the 50S ribosomal protein L21 (P rpl21 ) exhibited the strongest activity among the 26 identified promoters. Furthermore, type III pantothenate kinase from Pseudomonas putida ( Pp coaA) was overexpressed in C. ammoniagenes under the control of P rpl21 , CoA yield increased approximately 4.4 times.
Conclusions ： This study provides a paradigm for rational isolation of promoters with different activities and their application in metabolic engineering. These promoters will enrich the available promoter toolkit for C. ammoniagenes and should be valuable in current platforms for metabolic engineering and synthetic biology for the optimization of pathways to extend the product spectrum or improve the productivity in C. ammoniagenes ATCC 6871 for industrial applications.
Liver transplantation in Jehovah’s witnesses: 13 consecutive cases at a single Institution
Authors: Costanzo Diego , Bindi Maria , Ghinolfi Davide , Esposito Massimo , Corradi Francesco , Forfori Francesco , De Simone Paolo , De Gasperi Andrea , Biancofiore Gianni 
Published: October 2019

Abstract
Jehovah's Witnesses represent a tremendous clinical challenge when indicated to liver transplantation because they refuse blood transfusion on religious grounds and the procedure is historically associated with potential massive peri-operative blood loss. We developed a peri-operative management pathway with strategies toward a transfusion-free environment in the respect of the patients’ religious beliefs. Briefly, our peri-operative multimodal strategy to liver transplantation in Jehovah's Witnesses includes a pre-operative red cell mass optimization package and the intra-operative use of normovolemic haemodilution, veno-venous bypass and low central venous pressure. In a 9-year period, 13 Jehovah’s Witness patients received liver transplantation at our centre representing the largest LT program from deceased donors in JW patients that has been reported so far. No patient received blood bank products but 3 had fibrinogen concentrate and one tranexamic acid to correct ongoing hyper-fibrinolysis. There were 4 cases of acute kidney injury (one required extracorporeal renal replacement treatment) and one patient needed vasoactive medications to support blood pressure for the first 2 postoperative days. Two patients underwent re-laparotomy. Finally, of the 13 recipients, 12 were alive at the 1 year follow-up interview and 1 died due to septic complications. Our experience confirms that liver transplantation in selected Jehovah's Witnesses patients can be feasible and safe provided that it is carried out at a very experienced centre and according to a multidisciplinary approach
Fibrin γ/γ' influences the secretion of fibrinolytic components and clot structure
Authors: Cantero Miriam , Rojas Héctor , Anglés-Cano Eduardo , Marchi Rita 
Published: October 2019

Abstract
Background In healthy subjects fibrinogen γ/γ' circulates at 8-15% of the total plasma fibrinogen concentration. Elevated levels of this variant have been associated with arterial thrombosis and its diminution with venous thrombosis. The aims of the present work were to analyze the structure of the fibrin network formed on the top of human dermal microvascular endothelial cells (HMEC-1) at different fibrinogen γ/γ' concentrations, as well as its influence on the secretion of fibrinolytic components. Methods The kinetics of fibrin polymerization on top of HMEC-1 cells with 3, 10, and 30% fibrinogen γ/γ' was followed at 350 nm. The secretion of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI 1) by HMEC-1 were measured in the supernatant and cell lysates, after incubation with 1 nM thrombin, fibrin with 3%, and 30% fibrinogen γ/γ', using commercial kits. The influence of fibrinogen γ/γ' on fibrin structure on the surface of the HMEC-1 was followed with laser scanning confocal microscopy (LSCM). Results The kinetic of fibrin formation on HMEC-1 with 3% and 10% fibrinogen γ/γ' was similar. However, with 30% fibrinogen γ/γ' both the slope and final turbity were approximately 50% less. The LSCM images showed the dramatic effects of increasing fibrinogen γ/γ' from 3% to 30%. The uPA and PAI 1 concentrations in culture supernatants HMEC-1 cells treated with thrombin or 30% γ/γ' fibrin were two-fold increased as compared to basal culture supernatants and 3% γ/γ' fibrin-treated HMEC-1. In all stimulatory conditions the intracellular concentration of uPA was higher than in supernatants. In contrast, the intracellular PAI 1 concentration was decreased as compared to that measured in the supernatant, including the basal condition. Conclusion A concentration of 30% fibrin γ/γ' alter drastically fibrin structure on the cell surface and affects the secretion of uPA and PAI 1 through its capacity to bind thrombin.
Zwakala Ndoda: a cluster and individually randomised aimed at improving testing, linkage and adherence to treatment for hard-to reach men in KwaZulu-Natal, South Africa
Authors: Rooyen Heidi van , Makusha Tawanda , Joseph Phillip , Ngubane Thulani , Kulich Michal , Sweat Michael , Coates Thomas 
Published: October 2019

Abstract
Background Men in sub-Saharan Africa are less likely than women to get tested for HIV, less likely to present for treatment, less likely to be maintained in treatment, more likely to have detectable viral load, more likely to transmit HIV with unprotected intercourse, and more likely to progress to AIDS and die sooner from HIV. The ultimate objective of this research is to provide evidence-based strategies to improve HIV testing and treatment of HIV-infected men. Methods This study is being conducted in the Greater Edendale Area and Vulindlela region in KwaZulu-Natal, South Africa. It is a two-stage design of a cluster-randomised trial and an individual randomised trial to test how structural and individual-level interventions address the demand-side factors that affect HIV testing and treatment for hard-to reach, high-risk men. It combines male-focused mobilization, community-based mobile HIV Testing Services and a small incentive to determine if the strategies singly and in combination can result in more men diagnosed with HIV, and more men linked to and maintained in care with undetectable viral load. Discussion A priority for sub-Sahara Africa is developing and evaluating novel and cost-effective strategies for identifying hard-to-reach groups such as men, linking them to HIV testing and care services and maintaining them in care to the point of viral suppression. We propose a combination prevention intervention that addresses men’s individual, interpersonal, and structural barriers to testing and care. This includes male-led mobilization to encourage uptake of testing and treatment; male-focused testing venues; male-only counselors; developing counseling models that are flexible and responsive to men; and strategies for adhering to clinic visits without missing work and navigating the health care system. By thoughtfully combining male-focused mobilization, testing and addressing some of the barriers to male engagement with health facilities, this study hopes to add to the growing evidence based about how to reach, test, link and maintain a hard to reach group such as men in HIV treatment and care services.
A five year retrospective analysis of common intestinal parasites at Poly Health Center, Gondar, Northwest Ethiopia
Authors: Ayelgn Meseret , Worku Ligabaw , Ferede Getachew , Wondimeneh Yitayih 
Published: October 2019

Abstract
Objective: Intestinal parasites are present throughout the world in varying degrees of prevalence due to many factors. The aim of this study was to determine the five-year trend prevalence of intestinal prevalence among patients who had been suspected for intestinal parasite infections. A retrospective study was conducted from 2009 to 2013 at Poly Health Center Gondar, Northwest Ethiopia. Samples were examined using direct saline wet mount methods. Statistical analysis was done using SPSS version 20 software and a P-value of < 0.05 was considered statistically significant. The results were presented in tables and graphs.
Results: During the study period, a total of 13,329 stool samples were requested for intestinal parasite diagnose and 5510 (41.3%) laboratory-confirmed cases were reported with a fluctuating trend. Ten different parasites were reported in each year with Entamoeba histolytica/dispar (16.8%) being the predominant parasite followed by Giardia lamblia (11.4%) and Ascaris lumbricoides (6.7%). Both males (49%) and females (51%) were equally affected (P=0.14). The intestinal parasite was reported in all age groups in the area but the highest and the lowest prevalence were reported in age groups of 20-29 years and 40-49 years, respectively (26.5% vs 6.4%) (P < 0.001).