Surfactant tolerance in the presence of mono and divalent reservoir ions, as well as the solubility of surfactant in high salinity and low salinity brine, are the two major requirements for any ...surfactant that is subjected to oilfield application. Herein, six poly(ethylene oxide) zwitterionic surfactants having different ionic headgroups and hydrophobic tail were synthesized for oilfield applications. They were characterized by various instrumental techniques (Fourier-transform infrared spectroscopy (FTIR), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF-MS), Nuclear Magnetic Resonance (NMR)) and the combination of these techniques allowed for us to deduce the structure. All of the surfactants revealed prominent solubility in high salinity and low salinity brine due to the presence of ethoxy units between the aromatic ring and amide group. The surfactant samples were oven aged for 90 days at reservoir temperature and a clear solution implies their excellent aqueous stability. Rendering to thermal gravimetric results, decomposition of surfactants was found to occur around 300 °C, which is higher than the reservoir temperature (≥90 °C). It was observed that the hydrophilic headgroup has no significant impact on the critical micelle concentration and other surface properties. However, the hydrophobic tail bearing benzene ring significantly alters the critical micelle concentration and other surface properties.
Water-based drilling fluids are extensively used for drilling oil and gas wells. However, water-based muds cause clay swelling, which severely affects the stability of wellbore. Due to two adsorption ...positions, it is expected that cationic gemini surfactants can reduce the clay swelling. In this work, quaternary ammonium dicationic gemini surfactants containing phenyl linkers and different counterions (Cl
and Br
) were synthesized, and the effect of variation in counterions on swelling and hydration properties of shales was studied. Numerous water-based drilling fluid formulations were prepared with different concentrations of surfactants to study the swelling inhibition capacity of surfactants. The performance of surfactant-containing drilling muds was evaluated by comparing them with base drilling mud, and sodium silicate drilling mud. Various experimental techniques were employed to study drilling mud characteristics such as rheology and filtration. The inhibition properties of drilling mud formulations were determined by linear swelling experiment, capillary suction time test, particle size distribution measurement, wettability measurements, and X-ray Diffraction (XRD). Experimental results showed that surfactant-based formulation containing bromide counterion exhibited superior rheological properties as compared to other investigated formulations. The filtration test showed that the gemini surfactant with chloride counterion had higher filtrate loss compared to all other formulations. The bentonite swelling was significantly reduced with increasing the concentration of dicationic surfactants as inhibitors, and maximum reduction in the linear swelling rate was observed by using a formulation containing surfactant with chloride counterion. The lowest capillary suction timer (CST) was obtained in the formulation containing surfactant with chloride counterion as less CST indicated the enhanced inhibition capacity. The particle size measurement showed that average bentonite particle size increased upon the addition of surfactants depicting the inhibition capacity. The increase in basal spacing obtained from XRD analysis showed the intercalation of gemini surfactants in interlayers of bentonite. The contact angle measurements were performed to study the wettability of the bentonite film surface, and the results showed that hydrophobicity increased by incorporating the surfactants to the drilling fluid.
One of the foremost causes of wellbore instability during drilling operations is shale swelling and hydration induced by the interaction of clay with water-based mud (WBM). Recently, the use of ...surfactants has received great interest for preventing shale swelling, bit-balling problems, and providing lubricity. Herein, a novel synthesized magnetic surfactant was investigated for its performance as a shale swelling inhibitor in drilling mud. The conventional WBM and magnetic surfactant mixed WBM (MS-WBM) were formulated and characterized using Fourier Transform Infrared (FTIR) and Thermogravimetric analyzer (TGA). Subsequently, the performance of 0.4 wt% magnetic surfactant as shale swelling and clay hydration inhibitor in drilling mud was investigated by conducting linear swelling and capillary suction timer (CST) tests. Afterward, the rheological and filtration properties of the MS-WBM were measured and compared to conventional WBM. Lastly, the swelling mechanism was investigated by conducting a scanning electron microscope (SEM), zeta potential measurement, and particle size distribution analysis of bentonite-based drilling mud. Experimental results revealed that the addition of 0.4 wt% magnetic surfactant to WBM caused a significant reduction (~30%) in linear swelling. SEM analysis, contact angle measurements, and XRD analysis confirmed that the presence of magnetic surfactant provides long-term swelling inhibition via hydrophobic interaction with the bentonite particles and intercalation into bentonite clay layers. Furthermore, the inhibition effect showed an increase in fluid loss and a decrease in rheological parameters of bentonite mixed mud. Overall, the use of magnetic surfactant exhibits sterling clay swelling inhibition potential and is hereby proffered for use as a drilling fluid additive.
This study aims to determine to which extent perceived information quality and emotional attachment with digital influencers can shape the purchase intention of consumers while considering the ...mediating effects of perceived influence and the moderating effects of influencer reputation. A hypothetical model is tested based on social learning and media dependency theories. The response of 298 online users was analyzed by using Smart PLS-SEM. Results show that followers-influencers emotional attachment and perceived information quality promote the mediating role of followers’ perceived influence to increase the follower purchase intention. Contrary, influencer reputation does not moderate the effect of perceived influence on purchase intention. This study provides valuable input to companies that can help them design their influencers’ marketing strategies.
Nurse turnover is an issue that impacts a hospital’s financial resources and the quality of patient care. There is a need to discover what actions can be taken to improve nurse retention.
Nurses’ job ...satisfaction has been shown to improve organizational outcomes, such as nurses’ retention. The objective of this study is to examines the relationship between intent to leave, job satisfaction and structural empowerment (SE), providing a theoretical basis for further research.
A convenience sample of 83 critical care nurses, recruited from two Facebook groups and the AACN website. The nurses completed a survey that used three tools; Conditions of Work Effectiveness II (CWEQ II), Job Satisfaction Survey (JSS), and Turnover Intention (TIS-6) to address 4 hypotheses to determine the relationship of the three constructs.
Findings indicated that SE was not significantly related to intent-to-leave; SE was positively related to job satisfaction (β=0.760, p<0.01) , and job satisfaction was negatively related to Intent-to-leave (β=−0.610, p<0.01).
The research provided a theoretical framework for further research on SE and its importance in improving job satisfaction and reducing turnover in critical nurse.
Concern has been raised during the last decade about energy production from economical sources. As a result, several aspects of pristine and cadmium (Cd) induced SnZrO
3
are investigated using ...first-principles calculations to forecast a material for applications, such as optical characteristics and optoelectronic devices, especially for solar cells. This study assesses the effects of the Cd on optical properties, structural properties, electrical band gap, and density of states. Generalized gradient approximation is used to examine how Cd affects the electronic behavior of the host material, thus directly influencing optical properties. Keeping the stability requirement in view, Cd is incorporated at the Sn site rather than the Zr site. Electronic bandgap (
E
g
), due to the systematic and gradual inclusion of Cd at the Sn site in SZO, decreases due to the emergence of new gamma points from 1.777 to 0.588 eV. Along with making the band gap smaller, cadmium addition also transforms direct nature of
E
g
into an indirect one. According to the density of states,
P
-states cause a decrease in the bandgap. The change in electronic properties directly influences the optical properties of SZO after Cd inclusion, such as refractive index dielectric function and other optical properties. The static refractive index for pristine SZO is 3.75, and we observe that it decreases due to Cd inclusion except at
x
= 0.33. The presented results predicted that the Cd-doped SZO is a replacement candidate for the present solar cell because of its optical response.
This study describes how varying oil/water contents affect emulsion formation and the impact they have on emulsion droplet size, viscosity, and interfacial behavior. Crude oil (continuous phase) ...volume fractions of 40, 50, 60, and 70 vol % were probed in the various W/O emulsions formed. Experimental results from optical morphology revealed the emulsion droplets kept reducing as the crude oil fraction kept increasing, while the droplets were nearly unnoticeable in the emulsions derived from 60 and 70% crude oil. The viscosity–shear rate of emulsions produced from 40, 50, and 60 vol % crude oil exhibited a non-Newtonian behavior owing to the substantial volume of water content in their emulsions, whereas the viscosity–shear rate of the emulsion with 70 vol % crude oil exhibited a Newtonian behavior similar to the pure crude oil, suggesting a thorough blending of oil–water at this crude oil fraction. Besides, the viscosity–temperature measurements revealed that the viscosity of these emulsions diminished as the temperature increased and the viscosity reduction became more noticeable in an emulsion comprising 70 vol % crude oil. In the interfacial assessment, the increased crude oil content in the produced emulsion led to a sharp reduction in the interfacial tension (IFT). The IFT values after 500 s contacts between the emulsion and water (surrounding phase) were 11.86, 10.02, 8.08, and 6.99 mN/m for 40, 50, 60, and 70 vol % crude oil, respectively. Demulsification experiments showed that water removal becomes more challenging with a large volume of crude oil and a small water content. Demulsification performances of the lab-grown nonionic demulsifier (NID) after 10 h of demulsification activity at room temperature (25 °C) were 98, 90, 17.5, and 10% for the emulsions formed from 40, 50, 60, and 70 vol % crude oil, respectively, indicating that the demulsification degree decreases with an increasing crude oil content. Viscosity–time determination was applied to affirm the activity of NID on the emulsion formulated with a 50% crude oil fraction. The injection of NID in this emulsion triggered a sharp viscosity reduction, indicating the adsorption of NID at the oil–water interface and disruption of emulsifiers, enabling emulsion stability.
Community-led local development and community-driven development mechanisms are recent development phenomenon's adopted by many developing and developed countries, aimed at improving proactive ...community participation and quality of life along with social wellbeing of local community. The paper is about the role and severity of different barriers that prevent empowerment and community participation in the development of community led development in Pakistan. This paper initially illustrates the concept of empowerment and itsimportance, and then describes the findings of the project's assessment ofbarriers to empowerment among Citizen Community Boards in Pakistan. Audio-taped, structured, open-ended interviews were conducted with six leaders of Citizen Community Boards, who initiated and implemented the community driven projects. Discussion with respondents wasabout mechanisms of community participation;political and elite control; problems encountered at community level due to elite control; and other issues of capacity building and access to information. Interview results revealed that political interference and elite control hinder community participation at local level. Moreover, it is an obstacle that impedes community participation in local community-led development activities. Building capacity at local level is an important ingredient for sustainable development, as it not only provides local stakeholders with an opportunity to participate in decision-making, but also enables “community ownership”, a key component of empowerment. The findings of this study contribute towards greater understanding of developmental issues at local level and will help policymakers to focus on highlighted issues and problems faced by community-led development organizations.
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