bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of an Operation Critical Un-Biased Composite KPI to Measure Performance of Radiation Protection Activities
Authors: Yami Mohammed H. , Farea Saeed F. , Mudaibegh Isa H. , Rehman Aziz U. 
Published: October 2018

Abstract
Organizations measure or monitor single KPI and present this information at various operation stage for different levels of stakeholders and business managers. This becomes significantly complex and challenging when the requirement is to monitor multiple KPIs simultaneously. Higher level decisions are required to be made as to which KPIs are the most important and correctly represent the business unit activities. This leads to oversight, if multiple factors including priority and criticality of a certain KPI is not taken into consideration, and sometimes, the selected KPI can often be a reflection of SME bias than the relevance with the business unit performance.
This article presents a risk based approach in developing an un-biased composite KPI to measure the Performance of Radiation Protection Activities. The emphasis is to derive a measurement index, which adequately reflects the performance of radiation protection activities, in accordance with their importance and criticality to operations
Wettability Alteration and Enhanced Oil Recovery Using Low Salinity Waterflooding in Limestone Rocks: A Mechanistic Study
Authors: Tetteh Joel , Janjang Nazirah Mohd , Barati Reza 
Published: October 2018

Abstract
Low salinity waterflooding has recently gained more attention in carbonate formations mainly due to the cost effectiveness of this improved oil recovery technique. Despite all the recent work in this area, the underlying mechanism is still controversial, making field implementation very limited.
In this work, we explore the underlying mechanism behind the low salinity waterflooding effect (LSWE) in limestone rocks by investigating the role of divalent ions. This was achieved by implementing techniques such as contact angle and IFT measurements, zeta potential measurement and coreflooding experiments tailored towards a thorough understanding of the LSWE. Seawater and low salinity brines deprived of one divalent ion were prepared while maintaining theirionic strength.
Our data shows that reducing brine ionic strength results in wettability alteration which led to improved oil recovery in limestone rocks. This observation was attributed to surface charge reduction as measured using zeta potential. The absence of Mg2+ ion in both seawater and low salinity brine resulted in surface charge polarity change from positive to negative for pure limestone/brine interface, which resulted in a significant wettability alteration as measured on contact angle from oil wet to intermediate wet for limestone surfaces. The absence of Ca2+ ions had affected both zeta potential and contact angle resulting in the least alteration in rock surface wettability. Due to the low concentration of SO42− ions in the seawater and low salinity brines, SO42- had an insignificant effect on zeta potential and coreflooding. The surface charge of aged limestone/brine systems were determined, showing the influence of oil/brine interface over limestone/brine interface in the overall crude oil/brine/rock (COBR) system. This was due to the presence of carboxylic acid present in the crude oil and indicated proper aging procedure. Divalent ions varied the interfacial tension of seawater brine/oil system potentially resulting in better mobility control due to suppressed crude oil snap-off. At low salinity, the divalents ions present in the brine was insufficient to influence the interfacial tension.
The results from the various seawater and low salinity brines concludes that low salinity waterflooding effect occurs in limestones rocks partially due to the expansion of the electrical double layer as indicated by debye length. This results in detachment of carboxylic materials from the rock surface.
Application of Quantitative Cement Evaluation Using LWD Sonic Tool in Bohai Bay of China
Authors: Liu Feng , Zhang Binqi , Zhang Lei , Han Shim Yen , Zhou Xin , Li Lin 
Published: October 2018

Abstract
In Bohai bay, China, more than 150 highly deviated and horizontal wells are drilled every year. For most of these wells, it is difficult to evaluate the cement quality since a conventional cement bond log (CBL) log cannot be easily performed even with drill pipe conveyance and a tractor. Therefore, the well completion operation cannot always be performed with high enough confidence. This paper describes a new quantitative cement evaluation method using logging-while-drilling (LWD) sonic tools which has been utilized successfully for several wells in Bohai bay. For these highly deviated and horizontal wells, LWD sonic tools can easily overcome the conveyance difficulty and also offer a method to evaluate the cement bond quality in the same manner as a conventional CBL. For LWD sonic tools, due to the presence of a thick steel collar, the conventional amplitude only based approach to determining bond index is insufficient to evaluate both low and high bonding (Kinoshita, 2013) and must be integrated with the attenuation rate based measurement in the form of a hybrid approach (Izuhara, 2017) to cover the full range of bonding. Additionally, the bottom-hole-assembly (BHA) design should be optimized and procedures developed to mitigate noise while running the tool, particularly with the presence of casing scrapers in the logging run, as was done in Bohai bay.
8 wells in Bohai bay have respectively used LWD sonic to evaluate the cement bonding across different oil/water zones after the cementing operation, in both 9 5/8in and 7in casings. Despite the presence of a potentially high noise source casing scraper in the BHA for all runs, the tool signal was clear enough to deliver a bond index measurement in all cases. The bond index curve derived from LWD sonic tools shows that most of these wells have good bonding for the interface between the casing and cement. According to these results the perforation program was optimized and put into practice with a solid reference. The hybrid method of determining a bond index measurement with LWD sonic tools has been deployed in the industry since 2016. The successful applications of this method in 8 wells in Bohai bay have demonstrated its feasibility and its efficiency gains where conventional evaluation methods can be challenged. This complements the theoretical development of this approach and forms solid reference for more applications in other regions cross the world.
Locally Developed Surfactants for EOR in High Temperature High Salinity Carbonate Reservoir
Authors: Hussain S. M. , Kamal Muhammad Shahzad 
Published: October 2018

Abstract
Surfactant injection faces a great challenge due to severe conditions in the reservoir including high salinit y and temperature which results in surfactant precipitation and/or surfactant degradation. Considering the local reservoirs conditions, a surfactant which is stable under harsh conditions, reduce residual oil saturation, and provide viscosity to the water phase is highly desirable. Most of the commercially available surfactants for EOR are anionic in nature that could have very high retention on carbonate rocks.
To overcome the challenges, a variety of gemini cationic and conventional zwitterionic surfactants were synthesized and characterized by NMR (1H and 13C), FTIR and elemental analysis. The solubility tests were conducted for all gemini cationic and conventional zwitterionic surfactants. The heat stability was investigated by putting surfactants in an oven at 90oC for 15 days followed by structural elucidation.
The characterization data exhibited excellent heat stabilities of the surfactants. The NMR (proton and carbon) and FTIR analysis of the before and after aging samples showed no major difference which indicated the excellent heat stability of the surfactants. The solubility tests revealed that the majority of the gemini cationic and conventional zwitterionic surfactant were soluble in water. Surfactants containing carbon-carbon double bond in the hydrophobic tail exhibited good solubility in water.
The tested surfactants revealed excellent solubility and found to be stable in high temperature conditions and have great potential especially in carbonate reservoirs in order to avoid adsorption issues related to anionic surfactants.
Advances in Streamlining Development Wellbore Data from Concept to Completion
Authors: Abouhenidi Malak , Tadamarry Faizuddin , Fadul Reham , Radhi Yassir 
Published: October 2018

Abstract
Drilling techniques have advanced significantly in recent years with the drilling of complex, multi- lateral, and extended reach wells. While drilling, wellbore geological data are collected and managed from a broad and growing range of disparate sources, presenting a need to structure and streamline these data.
A new system has been implemented to play a vital role in streamlining geological data acquisition and management. This system acts as a catalyst for reservoir characterization geologists and management to analyze the complete life cycle of development wellbores from the pre-spud/planning phase, through drilling events, daily operations, and post-drilling analysis. This system was designed with the main objective of simplifying and automating daily drilling and geosteering activities. It also extends services to unconventional resources by tracking fracking data from design phase to quality control (QC) phase.
A new data structure was introduced to support multiple sidetracks (called deepening) for a single wellbore. It eases geologists' ability to track the entire motherbore activities in one place, including multiple deepenings for each wellbore. Wellbore related data and deepening data are monitored during the building, landing, and geosteering stages until the wellbore reaches its targeted depth (TD). The data collected during the planning phase includes (but is not limited to) estimated formation tops, target zones, logs, hole sizes, etc. Daily geological observations are captured during the drilling phase. Finally, at the completion stage, the system allows geologists to compare new data (actual) against existing data (planned) using statistical and analytical tools to generate an end-of-well report with the reservoir cutoffs. In addition, based on predefined user roles, the system sends automatic notifications to the Geosteering Operations Center (GOC) and field geologists as new information is obtained.
These features, and more, provide a solid platform for making critical business decisions, and facilitate moving from passive/reactive scenarios to active/proactive production control. With this new system in place, oil and gas wellbore operations have realized the benefits of streamlining wellbore data acquisition from conception to completion to improve processes and to make better-informed business decisions.
Optimizing Onshore Well Tie-In by the Use of Thermoplastic Composite Pipe
Authors: Rodulfo Jose L. , Tavares João 
Published: October 2018

Abstract
Well tie-in is an activity that requires careful measurement and fabrication methods. One of the most critical spools in onshore well tie-in is the riser connecting the wing valve in the X-mas tree to the choke valve. This piping section is regularly constructed of carbon steel and rated for high temperatures and high pressures, making it expensive and difficult to manufacture. The process of measurement and fabrication can only be initiated after the rig installs the X-mas tree in order to obtain as-built measurements. In order to optimize well tie-in, Saudi Aramco installed its first two non-metallic flexible onshore risers in two oil producers.
The non-metallic flexible onshore riser is a thermoplastic composite pipe (TCP) manufactured from carbon fiber and Polyether Ether Ketone (PEEK). This construction enables it to be lightweight, strong, and able to accommodate high levels of bending strain (flexible). This TCP can be manufactured to sustain pressures of up to 15,000 psi, temperatures of up to 248 °F, and corrosion resistance to seawater, H2S and CO2. This paper describes in detail the TPC onshore riser technology design, installation and performance evaluation process.
TCP can mitigate elevation/orientation changes of wing valves and consequently accelerate tie-in procedures. The installations of these non-metallic risers were performed in under five hours each. This optimization allows for cost and time savings, as well as releasing locked potential.
This paper provides a case study of the first installations of non-metallic flexible onshore risers for well tie- in in Saudi Arabia. By comparing the conventional method of installing carbon steel sections with TCP, the reader will be able to benefit from the technology benefits analysis, lessons learned, and future applications of this technology.
An Unusual Behaviour of Fluids in Pendant Drop Measurements
Authors: Almisned Omar A. 
Published: October 2018

Abstract
Based on the shape and size of a formed drop of fluid introduced into another fluid (provided the two fluids are immiscible), many parameters such as Interfacial tension (IFT) are determined. In addition, investigation of the effect of a particular parameter on the IFT can be achieved by measuring the change in IFT with the variation in the parameter.
Interfacial tension, capillary forces, and wettability are the factors affecting the shape of the drop of a lighter fluid through the tip of the apparatus of the pendant drop method into a heavier fluid. Before introduced to the cell, the two phases were distinct and the contact line separating the two phases was thin and clear indicating an immiscible mixture. At constant pressure, the temperature was incrementally increased in the two-phase fluid system, and the shape of the forming pendant drop is observed and captured by a camera.
With many attempts made to form the pendant drop, the drop was never formed at specific degrees of temperature. Although the fluids had come into complete equilibrium in the laboratory before introduced to the pendant drop cell, an unusual behaviour of the two fluids has been observed. The forming and un- forming of the drop as temperature was increased has not been consistent. The two phases at some temperatures were behaving as if they were somewhat miscible. Captured pictures of the behaviour of the fluids are shown and an attempt to explain the reasons of the unusual behaviour is presented in this paper.
The unusual behaviour suggests that the IFT – temperature relationship is a complex phenomenon and confirms some inconsistencies reported in the literature. Possible reason for the strange behaviour is that although the pendant drop method is a well-established technique for measurement of the interfacial tension (IFT), it may not be applicable for all IFT measurements conditions and/or the composition of the fluids used in the system.
Enhanced Oil Recovery by Polymer Flooding: Optimizing Polymer Injectivity
Authors: Al-Shakry Badar , Shiran Behruz Shaker , Skauge Tormod , Skauge Arne 
Published: October 2018

Abstract
Polymer flooding has been widely applied through past decades to increase oil recovery after waterflood. Water-soluble polymers are used to increase the viscosity of injected water that is a requirement for better sweep efficiency, but accelerated production due to polymer flooding may be limited by reduced injectivity. The objective of this paper is to give guidelines for optimizing polymer injectivity as key parameter for polymer flooding design.
Analysis of polymer injection data from field tests, and different analytical and simulation approaches from academic or commercial simulators will be discussed. Field realistic laboratory flooding in porous medium has been performed. Presented experiments study the influence of pre- injection treatment like pre-shearing or other methods on rheological properties in porous medium. Injectivity is discussed in relation to polymer molecular weight, polymer concentration, pre-treatment, and presence of oil.
Field scale injectivity is reviewed from available literature data. Impact of fracturing has been analyzed in order to isolate the matrix impact on injectivity and compare to laboratory data. Investigations show that injection pressure build up in the near wellbore region, which is also referred to as polymer shear thickening behavior, limits the injectivity of polymer solutions. The effect is more significant when high molecular weight polymer is injected compared to high polymer concentration. Hence, pre-shearing the polymer solution prior injection weakens the elastic properties of polymer while maintaining its viscous properties. Also, better polymer injectivity observed when oil is present (two phase flow) in porous media compared to no oil present (one phase flow).
This paper will discuss polymer injectivity and isolate key parameters for optimizing injectivity. The data from this study gives guidelines for optimizing polymer injectivity.
Screening of Surfactants and Polymers for High Temperature High Salinity Carbonate Reservoirs
Authors: Kamal Muhammad Shahzad , Sultan Abdullah , Hussein Ibnelwaleed , Hussain S M , AlSofi Abdulkareem M. 
Published: October 2018

Abstract
Carbonate reservoirs typically exhibit significant heterogeneity, high temperature and high salinit ies. Surfactant and polymer selection for such reservoirs is a challenging process where extensive laboratory investigations are required to reach optimum concentration and formulation.
In this work, we have evaluated a number of anionic, cationic, nonionic, and amphoteric surfactants (total 28 surfactants) and four different polymers for high temperature and high salinity carbonate reservoirs. Surfactants used were mainly: alkyl sulfonate, olefin sulfonate, alcohol ethoxylate, carboxyl betaine, ethoxylated fluorocarbon, amine oxide-based fluorocarbon, carboxy betaine, propoxylated alcohol, linear alcohol ethoxylate, and alkyl benzene sulfonate. Surfactants were evaluated using a series of evaluation steps which include but are not limited to evaluation of compatibility, phase behavior, interfacial tension, adsorption, rheology, and core-scale performance.
Almost all anionic and cationic surfactants were either incompatible or thermally unstable. None of the anionic surfactants (sulfate, alcohol propoxylate and ethoxylate, phosphate and sulfonate), provided by various companies were thermally stable at harsh reservoir conditions. Most of the surfactants from amphoteric and nonionic classes were thermally stable and compatible at harsh reservoir conditions. Fluorinated amphoteric surfactants showed very good thermal stability at 90oC but their IFT was relative ly high (&gt;1 mN/m). Similarly, fluorinated non-ionic surfactants showed good thermal stability but relative ly high IFT (&gt;1 mN/m). Hydrocarbon surfactants were compatible, thermally stable and showed lower IFT values (10-2 mN/m). For core flooding experiments, fluorinated amphoteric surfactants and hydrocarbon surfactants were selected. Although fluorinated amphoteric surfactants showed relatively high IFT, they were selected due to good thermal stability, lower adsorption and synergistic viscosity enhancement with the selected polymers.
The extensive screening of surfactants and polymers for high temperature and high salinity carbonate reservoirs improved our understanding of chemical selection for such conditions. This study could be used as a guideline in future research for selection of surfactants and polymers.
The Characteristics and Adjustment Technology of Surfactant/Polymer Binary Flooding in Conglomerate Reservoir
Authors: Gao Ming , Lv Jianrong , Gao Jian , Zhang Shanyan , Wang Qiang , Wang Xiaoguang , Chen Lihua 
Published: October 2018

Abstract
The recovery factor of surfactant/polymer binary flooding field test in conglomerate reservoir is 14.6% now and it will reach to 18% by prediction. Nevertheless, it has not achieved good results in the early stage. Conglomerate reservoir is more complex and special. The method used in sandstone reservoirs can't be used directly in the conglomerate reservoir. In the early stage of SP flooding, the mature injection technique of sandstone reservoirs was adopted, but the phenomenon of high polymer concentration appeared.
The reservoir and porous characteristics of conglomerate reservoir was analyzed by intrusive mercury curve and pore throat distribution. The law of SP flooding was studied by micro experiment and nuclear magnetic resonance. Comprehensive analyses of SP flooding between conglomerate reservoir and sandstone reservoir were conducted, including SP flooding water cut, injecting SP pressure, time of polymer appearing in production fluid, producing polymer speed and incremental oil recovery. In order to find out the law of different type's reservoir moving, the casing logging analyses was carried out.
Due to the presence of the small grain between the large gravels, the distribution of pore and throat in conglomerate reservoir was characterized by two peaks. It was found that the remaining oil after water flooding was mainly in the pores with radius 1-5μm in the conglomerate reservoir.
Because of the existence of the macro pore path, the initial chemical flooding system had a rapid advance, and the effect was obvious seen after the profile control. The molecular weight of the polymer should be appropriately reduced according to the pore and throat sizes of the reservoir after the macro pore path were blocked by large molecular weight polymers. The matching relationship between polymer and reservoir was reestablished, and the molecular weight and injection concentration of the polymer were adjusted, and the effect of oil increasing was obvious.
The most significant new finding was that the SP system realized the utilization of 30-50mD reservoir by casing logging, which reduced the lower limit of SP flooding to 30mD. This is important because the reserves ratio of 30-50mD reservoir account for a large proportion in the conglomerate reservoir.
The SP flooding in conglomerate reservoir is different from the conventional chemical flooding. The novelty of this paper is to find the characteristics and appropriate adjustment method, which will provide the necessary support for future applications.
Enhancing the Foam Stability Using Surfactants Mixtures
Authors: Almobarky Mohammed , AlYousef Zuhair , Schechter David 
Published: October 2018

Abstract
This work investigated experimentally the potential of the mixture of two anionic surfactants to reduce the mobility and enhance the oil recovery by generating stronger foam than that of the individual surfactants. Foams of the Alcohol Alkoxy Sulfate (AAS), Internal Olefin Sulfonate (IOS) surfactants and their mixtures were compared in bulk and in porous media. In bulk, after the foam has been generated by shaking, the foam columns decay was monitored to measure the foamability and foam stability. Furthermore, interfacial tension was measured for all surfactants solutions for explanation purposes and foam stability interpretations. Dynamically, Boise sandstone was used for surfactant-nitrogen co-injection for mobility reduction evaluation and foam viscosity measurements. Finally, the enhanced oil recovery was investigated by conducting core-flooding experiments for foam application after water flooding.
AAS surfactant showed impressive foamability in NaCl brines, but medium to poor foam stability especially with crude oil. On the other hand, IOS was the best in Deionized Water (DW) especially with crude oil, but poor foamability in brine. The synergism was more obvious in brine than in DW. For instance, the mixture provided five times and four times longer foam half-lives than AAS in absence and presence of crude oil, respectively. Dynamically, the foam generation was observed by the pressure drop jump during the surfactant-gas co-injection. The mixture reduced the mobility 13 and 5 times in comparison with that of AAS. Finally, the application of foam flooding as a tertiary recovery process resulted in 7.5% additional oil recovery by the mixture compared with 2.5% for AAS.