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Green and low cost CO2 and CaO were used to stimulate amine emulsions to reveal the responsive behavior of amine emulsions. On this basis, oil-based drilling fluids responsive to CO2 and CaO were formulated and their properties were evaluated. The results showed that the amine emulsions inversed from water-in-oil state to oil-in-water state readily and their rheological behavior underwent transitions of decreasing, rising again and decreasing again via induction by CO2. These CO2 responsive behaviors could be reversed by CaO. Oil-based drilling fluids prepared based on the amine emulsions with oil-water volume ratios of 50:50 to 70:30, densities of 1.4–2.0 g/cm3 had good rheological and filtration properties at 160 °C; and be readily cleaned up using CO2 bubbling. The useless solid phase with low density could be removed efficiently via reducing the viscosity of emulsion by CO2 and the residual liquid phase could be restored to the original state by CaO and reused to prepare drilling fluid. The mechanisms analysis indicated that CO2/CaO induced the reversible conversion between amine emulsifiers and their salts, which enabled the reversible regulation of both the hydrophilic-lipophilic balance of amine emulsifiers and the emulsion particles' size and finally caused the controllable-reversion of the form and rheology of amine emulsion.

Shale hydration is the main cause of wellbore instability during drilling using water-based drilling fluids (WBD). In this work, NH2- and HO-functionalized ionic liquids (ILs) were investigated for their performances on inhibiting the shale hydration, as well as their influences on the properties of WBD, using immersion and sedimentation tests, linear swelling test, hot-rolling dispersion test, rheological and filtration experiments. The mechanisms were identified by X-ray diffraction (XRD), zeta-potential and particle size distribution analyses, scanning electron microscopy (SEM) and related theoretical analysis. Evaluation experiment results showed that the NH2-functionalized IL had the best inhibition performance, followed by poly(propylene glycol)bis(2-aminopropyl ether), HO-functionalized IL and KCl. NH2-functionality was more favorable to shale inhibition than HO-functionality. When used in WBD, ILs could prevent viscosity building-up at high temperature, but cause filtration and inhibition failure, which could be mitigated when polyanionic cellulose (PAC) was added in WBD prior to inhibitors. Three critical observations helped elucidate the inhibitive mechanisms: the intercalation of cationic groups of ILs into the clay interlayers, the decrease of both interlayer spacing and double layer thickness. The NH2-functionalized IL allowed the smallest interlayer spacing and double layer thickness and therefore performed best in inhibition. The inhibition failure in WBD with ILs depended on two aspects: the consumption of ILs untimely and the filtration failure of WBD. PAC could decrease both of ILs’ loss within WBD and water loss toward shale, mitigating the WBD’s inhibition failure. Our work will facilitate the rational design of efficient and environmentally acceptable inhibitors and their rational applications in WBD for drilling shale formation.

This paper reviewed a one-term experiment on integrating internet-based language laboratory (IBLL) in teaching writings kills with the know-want-learn (KWL) plus model to second-year non-English-majored college students from Yangtze University. Subjects in this study consisted of 92 non-English-majored college students in the control group (CG) and 91 non-English-majored college students in the experimental group (EG). The results showed that 1) compared with a teacher-dominated approach for CG, internet-based language laboratory with KWL plus model of meta-cognitive writing strategy instruction for EG did a better job in enhancing students’ writing skills; 2) there were significant differences between males in CG and EG, and females in CG and EG; 3) students in EG held the positive response for the combined instruction.

Many non-English-majored graduates in colleges or universities complain about study stress. The purpose of the present study was to learn about non-English-majored graduates’ actual burnout situation and to seek intervention; a questionnaire survey and written interviews were conducted in a local comprehensive university in China. 109 non-English-majored graduates were participants in this study. The results in this study showed that: 1) the participants experienced a low to medium level of learning burnout; 2) significant differences were found in the aspects of gender, grades and one subscale of inefficacy in majors. No significant differences were found two subscales (exhaustion and cynicism) in the aspects of majors; 3) meanwhile, the results of the interviews indicate four causes of learning burnout. Internal and external supports are categorized as the burnout reducers. As for intervention, non-English-majored graduates, the organization (colleges or universities) and society should work together to buffer the burnout syndrome.

Clay is closely associated with the drilling of oil and gas by influencing the shale wellbore stability and the rheology of drilling fluids. In this work, four imidazolium-based ionic liquids (ILs) were used to modify the typical clay (i.e., sodium bentonite (Na-Bent)), and their effects on the Na-Bent rheological and swelling properties were evaluated by shear rheological measurements, immersion experiment, linear swelling measurements. The mechanisms involved were identified by using fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Zeta-potential and environmental scanning electron microscopy (ESEM) analysis. Evaluation experiment results showed that the adsorption of each IL could both significantly affect the Na-Bent rheological property and inhibit the Na-Bent swelling, which strongly depended on ILs' structures and concentrations. The mechanism study revealed that the cationic groups of ILs could adsorb on Na-Bent prior to water molecules, followed by expelling water and compressing the double electrode layers, and therefore inhibit the Na-Bent swelling. The adsorption of ILs could also change aggregation behaviors of the Na-Bent particles, by which the “house of cards” structures in Na-Bent dispersions were improved or destroyed, resulting in changes in rheological properties of Na-Bent dispersions.