新型超支化大分子季铵型抑制剂的制备及性能评价

以二乙醇胺、丁二酸酐为原料,合成端羟基超支化大分子；用环氧丙基三甲基氯化铵进行末端基团改性，引入季铵盐阳离子基团制备了一种新型季铵盐抑制剂HBP-TAC，其结构经红外光谱、核磁和元素分析表征。考察了端基取代度与浓度对抑制膨润土水化膨胀性能影响，并对滚动回收率及与钻井液配伍性进行了评价、实验结果表明：该类抑制剂对膨润土的水化膨胀有一定抑制作用，加入1%多取代HBP-T2，抑制效果能达到95.31%；在高温130℃条件下，页岩滚动回收的一次回收率为91.8%，二次回收率为80.1%；抑制剂与水基钻井液体系相容性较好，并对滤失性有一定改善效果。      

Emulsification properties of a star-shaped anionic surfactant in oil-based drilling fluid

A novel star-shaped sulfonate surfactant, synthesized with triethanolamine, was identified as a hydrophilic emulsifier which could form a stable water-in-oil emulsion. The interfacial film strength was measured by suspension drop method. The emulsification properties of emulsions were obtained by the emulsification rate experiment and demulsification voltage measurement. The emulsion shows an excellent emulsification effect when the addition of star-shaped anionic surfactant into oil-based drilling fluid was 2.0?wt%. In addition, the properties of surfactant in drilling fluid with different adding amounts were studied by rheological properties, thermal stability analysis and filtration experiments. The results show that star-shaped anionic surfactant used as emulsifier can improve the performance in oil-based drilling fluid, which maybe provides a new idea for this type of surfactant.     

A Study of the Influence of Nanoparticles on the Properties of Drilling Fluids

The effect of nanoparticles with different compositions and sizes on the rheological properties, filtration losses, and lubricating ability of drilling fluids has been experimentally studied. Nanoparticles of silicon, aluminum, and titanium oxides have been examined, while an aqueous bentonite suspension with a solid phase mass fraction of 5% has been used as a basic model of a drilling fluid. The concentrations and sizes of nanoparticles in the drilling fluids have been varied from 0.25 to 2 wt % and from 5 to 100 nm, respectively. It has been shown that the addition of nanoparticles substantially changes the properties of the drilling fluids. In contrast to suspensions of particles with macro- and microscopic sizes, the rheological parameters, filtration losses, and lubricating and sticking abilities of the suspensions containing nanoparticles depend on the size and nature of the latter and vary markedly already at low nanoparticle concentrations.     

Removal of natural uranium from water produced in the oil industry using Algerian bentonite

Batch sorption experiments have been carried out to remove natural uranium (NORM) from water obtained together with crude oil and natural gas, using Algerian bentonites. The effect of some important factors such as S/L ratio, pH, initial concentration, particle size was evaluated and a kinetic study performed. The value of the distribution coefficient (K _d) at equilibrium for natural uranium varied from 30 to 600 cm³·g⁻¹ and 50 to 1100 cm³·g⁻¹ (∼10% margin error) using natural bentonite and drilling bentonite, respectively. The isotherms showed that the data are consistent with both Freundlich and Langmuir models.     

Comparison and application of different empirical correlations for estimating the hydrate safety margin of oil-based drilling fluids containing ethylene glycol

As the oil and gas industries continue to increase their activity in deep water, gas hydrate hazards will become more serious and challenging, both at present and in the future. Accurate predictions of the hydrate-free zone and the suitable addition of salts and/or alcohols in preparing drilling fluids are particularly important both in preventing hydrate problems and decreasing the cost of drilling operations. In this paper, we compared several empirical correlations commonly used to estimate the hydrate inhibition effect of aqueous organic and electrolyte solutions using experiments with ethylene glycol (EG) as a hydrate inhibitor. The results show that the Najibi et al. correlation (for single and mixed thermodynamic inhibitors) and the Ostergaard et al. empirical correlation (for single thermodynamic inhibitors) are suitable for estimating the hydrate safety margin of oil-based drilling fluids (OBDFs) in the presence of thermodynamic hydrate inhibitors. According to the two correlations, the OBDF, composed of 1.6 L vaporizing oil, 2% emulsifying agent, 1% organobentonite, 0.5% SP-1, 1% LP-1, 10% water and 40% EG, can be safely used at a water depth of up to 1900 m. However, for more accurate predictions for drilling fluids, the effects of the solid phase, especially bentonite, on hydrate inhibition need to be considered and included in the application of these two empirical correlations.     

Fabrication of magnesium bentonite hollow fibre ceramic membrane for oil-water separation

In this study, low-cost magnesium bentonite (MB) was used for the fabrication of bentonite hollow fibre (BHF) membrane with high pure water flux. MB powder was initially characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), particle size distribution (PSD) analyser, Brunnauer -Emmett- Teller (BET) method, and field emission scanning electron microscope (FESEM). The BHF membrane obtained was then fabricated through dope suspension mixing, phase inversion and sintering process. The dope suspension was prepared by mixing MB, dispersant, polymer binder, and solvent using a planetary ball mill. While the spinning process was carried out at the extrusion rate of 8 mL/min, a fluid bore rate of 10 mL/min and air gap of 5 cm, and this was followed by sintering operation at 950 °C, 1000 °C, 1050 °C, and 1100 °C. The resulting BHF membrane was characterized by scanning electron microscopy (SEM) and XRD; the porosity test, water flux and oil rejection were also examined. The SEM surface morphology of BHF at sintering temperature of 950 °C showed spongy-like and nested macrovoids structure; the porosity was 49.09% with a mean pore size of 3.9 µm. The performance test on the bentonite-based hollow fibre membrane showed that the membrane prepared at 20 wt% and sintering temperature of 1000 °C, which induced high and stable permeate water flux and oil rejection of BHFC membrane were 544 L/m² h and 97%, respectively. The results have shown that the presence of magnesium in bentonite can enhance and promote the needed support material for the fabrication of hollow fibre ceramic membrane.     

Synthesis,characterization and evaluation of long-acting hyperbranched cationic polymer clay stabilizer used in water flooding

In the process of waterflooding development, it is of great importance to prevent the clay from hydration swelling and migration dispersion for protecting the formation and improving the water flooding efficiency. For those reasons, we successfully synthesized a cationic clay stabilizer (HBP-QAT) through melting polycondensation and cationic modification with maleic anhydride, diethanolamine, epichlorohydrin, triethylamine, and trimethylolpropane as monomers and p-toluene sulfonic acid as a catalyst. The chemical structure, cation degree, and molecular weight of HBP-QAT were studied by using FTIR, ¹H NMR, sodium tetraphenylborate (STBP) back titration, and gel permeation chromatography (GPC). The obtained results showed that HBP-QAT was a hyperbranched unsaturated polyester amide with a low molecular weight and a high cation degree, with corresponding values of 28400, and 44.2%, respectively. The clay stability and durability of HBP-QAT were evaluated by linear anti-swelling, water flushing, and cutting rolling recovery tests. The obtained results showed that HBP-QAT has an excellent anti-washing capacity and a long-term inhibition effect. The initial anti-swelling rate of 1.0 wt% HBP-QAT reached 92.37%, and the anti-swelling rate of 1.0 wt% HBP-QAT also remained at 85% after flushing 10 times with water. Besides, the two cutting rolling recoveries exceed 72%. Most importantly, the inhibition mechanism of HBP-QAT was studied by zeta potential, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and contact angles analyses, and thus we proposed an inhibition mechanism, presenting as follows. HBP-QAT inhibited the clay hydration swelling by neutralizing negative charges on the surface of the clay particles to compress the electric double layer, strongly adsorbing on the surface of the clay particles, and forming a waterproof polymer membranes, restraining water of intrusion into the clay interlayer.     

基于深孔改进电极发射光谱法同时测定地球化学样品中微量银、锡、硼

采用深孔改进电极,一米平面光栅交流电弧摄谱法同时测定地球化学样品中微量银、锡、硼的含量。以三氧化二铝、硫酸钾、氟化钠和碳粉作缓冲剂,锗作内标。方法检出限为:银0.015μg/g、锡0.32μg/g、硼1.0μg/g,相对标准偏差(RSD)为5.8%~7.5%。实验用国家一级标准物质进行验证,方法的测定值与标准值相符。     

Bentonite stability,speciation and migration behaviour of some critical radionuclides

The contribution is focused on chemical, geochemical and mineralogical research of bentonite stability with the aim to determine the effect of saturation medium composition and loading by heat on bentonite stability. The main part of the research is directed to the experimental results of bentonite and bentonite leachate samples obtained for the bentonite interaction under laboratory experiments. Computer-modeling methods were used to calculate equilibrium thermodynamic principles, the distributions of predominant aqueous species, and potential solubility controls for the environmentally important oxidation states of each investigated radioactive contaminants. The Eh–pH diagrams of individual chemical species of the tested radionuclides were calculated by the geochemical software tool Geochemist’s Workbench that included the actual chemical compositions of the solid–liquid systems under the given experimental conditions. It was confirmed that smectites are transformed to more stable silicate phases, such as illite/smectite mixed layers, illite. The data obtained from the model calculations conform with experimental results. The effect of the variable aqueous phase composition on bentonite stability using Ca–Mg and Na–Ca bentonites for the experiments was studied. The synthetic granitic waters with the higher concentration of the K⁺ and Mg²⁺ cations were applied for the study of bentonite stability.     

Application of polymeric drilling fluids for reducing wearing of drill bit

The drill bit or cutting tool is a very important part of the rock drilling operation, it is directly associated with the rate of penetration. Bit wearing has significant involvement of time, labor, and wealth. By identifying the effect of various machine and rock parameters on bit wearing, the optimum working condition can be adopted to achieve high drilling efficiency. In this experimental work, the rate of penetration and parameters of drilling fluids (i.e. type, additives, and concentration, etc.) were optimized to identify their respective impact on the bit wearing of impregnated core diamond bit. The study has been conducted on a laboratory rotary drilling setup. The role of aqueous solutions of carboxymethyl cellulose (CMC), guar gum (GG), and polyacrylamide (PAM) has been examined as polymeric drilling fluid additives on sandstone rock samples and compared with the results of tap water alone as drilling fluid. A significant decrement in bit wearing has been noticed with all additives and the maximum reduction of 70.02% was achieved with CMC fluid additive.     

The synthesis of trimeric comb-type nonionic surfactants and their application in microemulsion flushing fluid

In order to effectively remove the oil-based drilling that remains on the wall of a well and improve the quality of well cementation, flushing fluid must be used to clean it. Due to its excellent flushing effect, microemulsion flushing fluid has been a hot area of research in recent years; the application, however, is limited because of its poor resistance to temperature. In this paper, for the purpose of enhancing the temperature resistance of microemulsion flushing fluid, a new type of comb-shaped trimeric nonionic surfactants N,N-bis(2-stearamidoethyl) stearamide was synthesized, and an anionic–nonionic surfactants composite oil-in-water microemulsion flushing fluid (ANC-MEFF in short) to flush the oil-based drilling was formed. Studies have shown that it has a good flushing effect on oil-based drilling between 20 and 160°C, and its flushing efficiency can reach 93% or even higher. Compared with the CW210L organic phosphorus flushing fluid (Number 1 in short), the flushing efficiency increased by about 20?~?40%, while the microemulsion flushing fluid formed by OP-10 (Number 2 in short) increased by 30% in high temperature, with the application temperature ranging from 20?~?60 to 20?~?160°C, respectively. Additionally, it was found that the microemulsion flushing fluid can make the borehole wall and casing wall change from “oil-wet” into “water-wet”, which is conducive to promoting the quality of cementation between the first and second interfaces intuitively.     

Sorption and desorption of radiostrontium on powdered bentonite: Effect of pH and fulvic acid

The effect of pH and fulvic acid on the sorption of Sr on bentonite was investigated by using batch experiments. The sorption and desorption isotherms of Sr on bentonite were determined at room temperature, at pH 6.0±0.2 and in presence of 0.1M NaCl. It was found that the sorption of Sr is independent at pH<8, and then increases slightly with increasing pH. Fulvic acid increases the sorption of Sr significantly on bentonite at low pH, but decreases the sorption of Sr at pH>8. The sorption of Sr on bentonite can be described by a reversible sorption process and the sorption mechanism consists mainly of ion exchange. This revised version was published online in July 2006 with corrections to the Cover Date.     

A new experimental design to investigate the concentration dependent diffusion of Eu(III) in compacted bentonite

The 'in-diffusion method was used to study the diffusion behavior of Eu(III) in compacted bentonite. The results (K _d, apparent and effective diffusion coefficients) derived from the capillary method are in good agreement with the literature data for similar bentonite dry densities and similar radionuclide concentrations, and fits the Fick's second law very well. The method was used to study the effect of solution concentration (10^-7-10^-3 mol/l) on the diffusion and sorption behavior in compacted bentonite. The experiments were carried out in synthetic groundwater, at room temperature. The results suggested that the diffusion of Eu(III) in the bentonite was independent on the density of bentonite, but dependent on the solution concentration. In agreement to the literature, the K _d values from the capillary experiments are in most cases lower than those from batch experiments, they are about one-half to one-third the value to those from batch experiments. The difference between the K _dvalues from capillary and batch experiments are a strong function of the bulk density of the bentonite. The results suggest that the content of interlaminary space plays a very important role to the transport of Eu(III) in compacted bentonite.     

Sorption and diffusion of 90Sr2+in compacted bentonite investigated by a capillary method

Summary The effects of bentonite density and fulvic acid on the sorption and diffusion of ⁹⁰Sr²⁺in compacted bentonite were investigated by using a capillary method. The experiments were carried out at pH 7.0±0.1 in the presence of 0.01M NaClO₄. The results suggest that the sorption and diffusion of ⁹⁰Sr²⁺in compacted bentonite decreases with increasing the density of compacted bentonite. The presence of FA enhances the sorption of Sr²⁺, but reduces the diffusion of Sr²⁺in compacted bentonite. The porosity of the compacted bentonite plays an important role in the sorption and diffusion behavior of ⁹⁰Sr²⁺. Using the calculated effective diffusion coefficients the long-term relative concentration distribution of strontium was evaluated in compacted bentonite.     

Synthesis and performance evaluation of a water-soluble copolymer as high-performance fluid loss additive for water-based drilling fluid at high temperature

Drilling fluids are widely used in the drilling of deep wells to clean and transport the rock cuttings, maintain the sidewall of oil well, lubricate and cool the drilling bit, and control the formation pressures. The present work aims at improving the high-temperature resistance of water-based drilling fluid by using the newly synthesized fluid loss additive named PAASD. This copolymer was obtained through the solution polymerization of four kinds of monomers. The synthesis conditions with the optimal API filtration were studied by single synthetic experiment, and the chemical structure of final product was confirmed by FTIR spectroscopy. The target product was carried out with thermal stability analysis, rheological property, filtrate property, temperature resistant capacity, salt tolerance capacity, micro-crosslink structure property, particle size distribution and the compatibility performance experiment. The results showed that PAASD was an efficient fluid loss additive, and the API filtration of fresh water drilling fluid containing 2% PAASD was only 5.2 mL, it was 10.6 mL after aging at the condition of 200°C and 16 h. Besides, PAASD has a good thermal stability, salt tolerance, and it could improve the rheological property of drilling fluid system obviously. Therefore, it could be used as fluid loss additive of water-based drilling fluid in salty and high-temperature environment.     

有机改性膨润土对水中钙黄绿素的吸附性能

在微波作用下用十六烷基溴化吡啶(CPB)、十六烷基三甲基溴化铵(CTMAB)和盐酸萘乙二胺(NETH)对天然膨润土进行改性,制得了CPB-膨润土(CPB-Bt)、CTMAB-膨润土(CTMAB-Bt)和NETH-膨润土(NETH-Bt),并比较了它们对水中钙黄绿素的吸附性能.结果表明,在钙黄绿素浓度25 mg·L-1、...     

Modified bentonite by polyhedral oligomeric silsesquioxane and quaternary ammonium salt and adsorption characteristics for dye

To remove methylene blue dye from water by adsorption, bentonites were modified by polyhedral oligomeric silsesquioxane (POSS) and three kind of quaternary ammonium surfactants (dodecyl trimethyl ammonium bromide, tetrabutyl ammonium bromide, cetyl trimethylammonium bromide) in aqueous solution. Systematic adsorption experiments were carried out, the adsorption mechanism was studied, and the factors governing the adsorption of methylene blue on modified bentonite were discussed. The adsorption capacity of methylene blue on all three modified bentonites in 1000 mg·L⁻¹ solutions quickly reached equilibrium within 2000 s, and the removal rate was basically 100%; however, the removal rate in raw bentonite samples was only 60%. The pseudo second-order kinetic model can provide satisfactory kinetic data fitting. The obtained adsorption isotherms fit well with the Dubinin-Radushkevich isotherm model. The thermodynamic results showed that the adsorption process was a spontaneous endothermic physical adsorption process. With increasing pH and KCl concentration, the removal of methylene blue increased significantly. The results of this study confirmed that the modified bentonite is a candidate material as a cationic dye adsorbent.     

甲基葡萄糖苷对钻井液性能的影响

甲基葡萄糖苷对钻井液性能的影响;甲基葡萄糖苷;抑制作用;膜效率;活度;钻井液     

Ca-Fe/bentonite载氧体煤化学链燃烧反应特性

以天然石膏粉、膨润土(bentonite)和Fe(NO3)3·9H2O为原料,通过机械混合造粒法制备了钙基复合载氧体。在小型流化床反应器中,水蒸气作为气化-流化介质,研究了温度、活性组分含量及循环次数对复合载氧体反应活性的影响,同时考察了不同煤种化学链燃烧反应特性。实验结果表明,CaSO4含量为60%,Fe2O3为活性助剂的CaSO4-Fe2O3/ben(Ca-Fe/ben)载氧体平均磨损速率为0.089%/h。反应温度为900℃时,碳转化率达到95%所需的时间为20.8min,CO2平均干基浓度为95.99%,表现高的反应活性。10次氧化/还原反应后,CO2平均干基浓度保持在80%,载氧体保持良好的循环反应活性。同时,实验发现高挥发分高灰分的煤种更适于煤的化学链燃烧,且CO2浓度均保持在90%以上。粒径分布曲线表明循环反应中载氧体表现强的抗磨损能力。