Hydrophobic Small-Molecule Polymers as High-Temperature-Resistant Inhibitors in Water-Based Drilling Fluids

Water-based drilling fluids can cause hydration of the wellbore rocks,thereby leading to instability.This study aimed to synthesize a hydrophobic small-molecule polymer(HLMP)as an inhibitor to suppress mud shale hydration.An infrared spectral method and a thermogravimetric technique were used to characterize the chemical composition of the HLMP and evaluate its heat stability.Experiments were conducted to measure the linear swelling,rolling recovery rate,and bentonite inhibition rate and evaluate accordingly the inhibition performance of the HLMP.Moreover,the HLMP was characterized through measurements of the zeta potential,particle size distribution,contact angles,and interlayer space testing.As confirmed by the results,the HLMP could successfully be synthesized with a favorable heat stability.Furthermore,favorable results were found for the inhibitory processes of the HLMP on swelling and dispersed hydration during mud shale hydration.The positively charged HLMP could be electrically neutralized with clay particles,thereby inhibiting diffusion in the double electron clay layers.The hydrophobic group in the HLMP molecular structure resulted in the formation of a hydrophobic membrane on the rock surface,enhancing the hydrophobicity of the rock.In addition,the small molecules of the HLMP could plug the spaces between the layers of bentonite crystals,thereby reducing the entry of water molecules and inhibiting shale hydration.

Double-layer Modifi cation of Water-based Aluminum with SiO2 and Polyacrylic Acid by Solgel Process and in situ Polymerization

A double-layer aluminum consisting of an aluminum core and a shellof SiO2 and polyacrylic acid was synthesized.This modified aluminum was used to improve the corrosion resistance and dispersive property of aluminum in waterborne media.TEM,FTIR,XPS,and EDX determination showed that PAA and SiO2 were coated on the surface of aluminum.Evolved hydrogen detection showed that the corrosion resistance of composite particle had been markedly improved.Maximum corrosion inhibition efficiency of SiO2 coated aluminum（SiO2@Al）was 95.1% while that of double-layer coated aluminum（PAA/SiO2@Al）was 98.8%.Meanwhile,polyacrylic acid layer improved the agglomeration of aluminum significantly.According to the dispersibility test,the particle size of 50% volume fraction [d（0.5）] of aluminum,SiO2@Aland PAA/SiO2@Alwere 42,53,and 34 μm,respectively.

Synthesis and Characterization of Star-branched Polyisobutylene by Combination of Anionic Polymerization and Cationic Polymerization

A star-shaped multifunctional styrene-isoprene copolymer was synthesized with n-BuLi as initiator, divinyl benzene as coupling agent, cyclobexane as solvent by living anionic polymerization. Using this polymer as grafting agent, a novel star-shaped branched polymer, containing several polyisobutylene, was prepared via cationic ~aolymerization. The star PS-b-PI and star-branched polyisobutylene were characterized by GPC, ＇HNMR and FT-IR, and the effects of different adding order and the amount of grafting agent were investigated.

RESEARCH ON CATIONIC POLYMER WATER BASE DRILLING FLUIDS

Cationic polymer drilling fluid (CPDF) is a new water base drilling fluid in which high molecular weight (HMW) cationic polymer (CPAM) is an encapsulating and flocculating agent and organic quaternary ammonium compound (NW-1) acts as shale inhibitor. This paper describes the experimental results of cuttings recovery, particle size distribution layer spacing and Zeta potential, and discusses the inhibition of CPDF system and its major additives. The advantages of CPDF will be proved by its application in well LX-2.

Flocculating Properties of Water-Soluble Polymer-Colloid Complexes of Aluminoxane Particles with Weakly Charged Cationic Polyelectrolytes

The flocculating properties of polymer-colloid complexes (PCCs) formed via noncovalent interactions of positively charged aluminoxane particles (APs) with macromolecules of weakly charged cationic acrylamide copolymers from the Praestol and Organopol series have been studied. The PCCs that spontaneously formed during mixing of sols of a high-basicity aluminum polyhydroxochloride (APHC) with aqueous solutions of the copolymers exhibit high flocculating ability under the conditions of gravity sedimentation of the model kaolin dispersion with Сd = 8 g/dm3, and their efficiency exceeds both that of the copolymers and the earlier obtained PCCs with nonionogenic polyacrylamide (PAA). In contrast to weakly charged polycationites, the fully charged KF-99 polyelectrolyte does not form PCCs and the products of its mixing with APHC do not reveal an increased flocculating effect.

New Nano Polymer Materials for Composite Exterior-Wall Coatings

A triethylenetetramine epoxy mixture was synthesized through the reaction of a low-molecular-weight liquid epoxy resin with triethylenetetramine(TETA).Then triethyltetramine(TETA)was injected dropwise into a pro-pylene glycol methyl ether(PM)solution for chain extension reaction.A hydrophilic andflexible polyether seg-ment was introduced into the hardener molecule.The effects of TETA/DGEPG,reaction temperature and reaction time on the epoxy conversion of polyethylene glycol diglycidyl ether(DGEPG)were studied.In addition,several alternate strategies to add epoxy resin to the high-speed dispersion machine and synthesize MEA DGEBA adduct(without catalyst and with bisphenol A diglycidyl ether epoxy resin)were compared.It was found that the higher the molecular weight of triethylenetetramine,the longer the chain segment of the surface active molecule.When the equivalence ratio of amine hydrogen and epoxy group is low,the stability of lotion is good.When the ratio of amine hydrogen to epoxy group is large,the content of triethylenetetramine is small.The main objective of this study is the provision of new data and knowledge for the development of new materials in the coating and electronic industry.

Recyclable hydrolyzed polymers of intrinsic microporosity-1/Fe_(3)O_(4) magnetic composites as adsorbents for selective cationic dye adsorption

Polymers of intrinsic microporosity shows great potential for dye adsorption and magnetic Fe_(3)O_(4) are easy to be separated.In this work,hydrolyzed polymers of intrinsic microporosity-1/Fe_(3)O_(4) composite adsorbents were prepared by phase inversion and hydrolysis process for cationic dye adsorption.The chemical structure and morphology of the composite adsorbents were systematically characterized by several characterization methods.Using methylene blue as the target dye,the influences of solution pH,contact time,initial dye concentration,and system temperature on the methylene blue adsorption process were investigated.The incorporation of Fe_(3)O_(4) particle into hydrolyzed polymers of intrinsic microporosity-1 endow the adsorbent with high magnetic saturation(20.7 emu·g^(–1))which allows the rapid separation of the adsorbent.Furthermore,the adsorption process was simulated by adsorption kinetics,isotherms and thermodynamics to gain insight onto the intrinsic adsorption mechanism.In addition,the composite adsorbents are able to selectively adsorb cationic dyes from mixed dyes solution.Hydrolyzed polymers of intrinsic microporosity/Fe_(3)O_(4) shows only a slight decrease for methylene blue adsorption after 10 adsorption/regeneration cycles,demonstrating the outstanding regeneration performance.The high adsorption capacity,outstanding regeneration ability,together with simple preparation method,endow the composite adsorbents great potential for selective removal of cationic dyes in wastewater system.

Poly [ (chloromethyl) styrene-co-divinylbenzene] Continuous Rod Column of Weak Cation Exchange Chromatography and its Applications in the Separation of Biopolymers

Macroporous poly [(chloromethyl) styrene-co-divinylbenzene] continuous rod was prepared by direct polymerization of the monomers in the presence of a porogenic diluent inside an empty chromatographic column. A new 'in-situ' technique was used to modify the synthesized polymer rod for a weak cation exchanger and it has been used successfully for the separation of biopolymers. It was found that the back pressure of the continuous rod column was much lower and its surface was proved to be modified well.

Application of Polymers in Low Permeability Formations

For low-permeability sandstone reservoir with big channel, we researched the novel deep profile method alternative injection of anionic and cationic polymer. Evaluating various factors on adsorption capacity through lab test, the results show that with the increase of temperature, the adsorption capacity decreases and the cationic polymer is easier to be absorbed. With the increase of salinity, adsorption time or polymer concentration, the adsorption capacity increases. The adsorption equilibrium concentration of cationic polymer is 1500 mg/L;adsorption equilibrium time is 8 h. The adsorption equilibrium concentration of anionic polymer is 1000 mg/L;adsorption equilibrium time is 6 h. Physical simulation experiment shows that alternative injection of anionic and cationic polymer is better than injection of single polymer, and preferential injection of cationic polymer is better than preferential injection of anionic polymer. With the increase of injection rounds, sealing capacity gets better, but in view of cost, the rounds should not be more than 3. The profile control technique can obviously enhanced oil recovery, and water displacement recovery increases 41%. 2 wells were tested successfully in Henan Oilfield in June 2010. Approximate 154.47 tons of incremental oil was obtained with 2% water-cut decrease.

The effect of cations on gelation of cross-linked polymers

The effects of different cation concentrations and types on rheological property and stability of Guar, Xanthan, and Partially Hydrolyzed Polyacrylamide(HPAM) cross-linked gels were analyzed through experiments. Also, a new approach was developed to reduce the negative effects of cation by application of multi-walled carbon nano-tubes(MWCNTs). The presence of cations in cross-linked gel system will reduce the viscosity of gel, the higher the cation concentration is, the lower the viscosity will be. The bivalent cation has a greater viscosity reduction effect on gel than monovalent cation. The stability of cross-linked gels is worse with cations, this situation becomes more serious under higher salinity. MWCNTs were added to HPAM gel, cross-linked by(3-Aminopropyl) triethoxysilane(APTES), they surrounded cations and removed them from polymers and reduced the reaction possibility. This method enhances the viscosity and breakdown pressure of cross-linked gels, improves the stability of HPAM cross-linked gel under different operating conditions, and can be applied to related drilling projects.

Preparation of Cationic Chitosan-Polyacrylamide Flocculant and Its Properties in Wastewater Treatment

Chitosan derived from crab shells, was used to prepare the graft polymer in aqueous solution with acrylamide （AM） and methacrylatoethyl trimethyl ammonium chloride （DMC） as raw materials and ceric ammonium nitrate （CAN） as initiator. The flocculation ability of the resulting polymer （PCAD） was studied in waste water treatment experiments. Its properties were determined on the basis of the transmittance of waste water after flocculation. The effects of ehitosan and DMC content on PCAD＇s flocculation ability were studied. Floeculation experiments were also undertaken under various pH conditions. According to the experimental data, the flocculation ability could be improved when chitosan content decreased in the raw material, but the monomer conversion would decrease obviously. When the ehitosan＇s content was more than 65%, AM and DMC groups were less on each chitosan molecule. So PCAD＇s flocculation ability was poor. Similarly, high content of DMC would result in low monomer conversion and high flocculation ability. PCAD molecules with more DMC group had more positive charges. It was favorable to flocculation. However, monomer conversion would decrease with the increase of DMC content. The suitable conditions were that chitosan and DMC contents were 65% and 15-20%, respectively. The experiment data showed that PCAD had good flocculation ability under weak acidic condition. Its ability would be weakened by strong acidic or alkaline condition. The flocculation efficiency was the best at pH of 5.5 when PCAD＇s dosage was 8mg-Lk Compared with cationic polymer （the copolymer of AM and DMC, PAD）, PCAD showed better flocculation ability under acid and neutral conditions, but worse ability under alkaline condition.

Super-amphiphobic, strong self-cleaning and high-efficiency water-based drilling fluids

Based on the amphiphobic theory on underground rock surface, a super-amphiphobic agent is developed and evaluated which can form nano-micro papilla structure on rock, filter cake and metal surface, reduce surface free energy, prevent collapse, protect reservoir, lubricate and increase drilling speed. With this super-amphiphobic agent as the core agent, a super-amphiphobic, strong self-cleaning and high-performance water-based drilling fluid system has been developed by combining with other agents based on drilled formation, and compared with high-performance water-based drilling fluid and typical oil based drilling fluid commonly used in oilfields. The results show that the super-amphiphobic, strong self-cleaning and high-performance water-based drilling fluid has better rheology, and high temperature and high pressure filtration similar with that of oil-based drilling fluid, inhibiting and lubricating properties close to oil based drilling fluid. Besides, the super-amphiphobic system is non-toxic, safe and environmentally friendly. Field tests show this newly developed drilling fluid system can prevent wellbore collapse, reservoir damage and pipe-sticking, increase drilling speed and lower drilling cost, meeting the requirement of safe, high efficient, economic and environmentally friendly drilling. Compared with other drilling fluids, this new drilling fluid system can reduce downhole complexities by 82.9%, enhance the drilling speed by about 18.5%, lower drilling fluid cost by 39.3%, and increase the daily oil output by more than 1.5 times in the same block.

POLYMERIZATION OF 1-AZABICYCLO[4.2.0]OCTANE WITH CHIRAL TRICYCLIC AMINO ACID ESTERS FOR OBTAINING BIOMEDICAL MATERIALS

The cationic ring-opening polymerization of 1-azabicyclo[4.2.0]octane, commonly called conidine （1） was studied with some chiral tricyclic amino acid esters （6a-6f） as acylation agents to obtain optically active biopolymers （Sa-8f） of the different masses. The structures of the new compounds were confirmed by FT-IR, UV and NMR, and the distribution index of the molecular weights of the polymers was determined from SEC measurements.

Effect of cationic monomer structure on the aggregation behavior of amphoteric acrylic polymer around isoelectric point

Amphoteric polymer can be used as retanning agent in leather manufacture.It is particularly useful in chrome-free tanning systems since it can regulate the charge properties of chrome-free leather and enhance the fixation of anionic post-tanning chemicals in leather.However,the aggregation and precipitation of amphoteric polymer retanning agents around the isoelectric point(pl)hinder their wide application.Herein,we synthesized five amphoteric acrylic polymers(AAPs)by free radical copolymerization with acrylic acid and five different cationic acrylic monomers.The effect of cationic monomer structure on the aggregation behavior of AAPs was investigated.The aggregation of AAPs in aqueous solution showed pH and concentration dependence.Light scattering analysis showed that Poly(AAA-co-MAPTAC)and Poly(AA-co-DMAPMA)were in the shape of coiled linear flexible chains with small particle size(R_(g)7.6 nm and 14.8 nm,respectively)near the pl.However,Poly(AA-co-DAC),Poly(AA-co-DMC)and Poly(AA-co-DMAEMA)were in the shape of hollow spheres and exhibited serious aggregation.Quantum chemical calculations suggested that the amide groups in the cationic monomers MAPTAC and DMAPMA enhanced the nucleophilicity of AAPs.Thus the corresponding AAPs could carry a large number of cationic charges to slow their aggregation when the pH just climbed over the pl.The results are expected to provide theoretical reference for the synthesis and wide-spread application of AAPs.

隐形酸完井液用黏土稳定剂的合成及评价

隐形酸完井液用黏土稳定剂的合成与评价是一个复杂而重要的过程,它直接关系到油气井的完井效果和储层保护。以下是对完井液用黏土稳定剂的合成与评价的综合概述:PDADMAC24合成工艺简单,所用化工原料种类较少,生产工艺简单易行。室内实验结果表明,PDADMAC24是一种非常有效的完井液用黏土稳定剂,与缓蚀剂及添加剂的配伍性好,耐温高,稳定作用强,防膨率高达91.00%以上,可明显提高完井和保护储层的效果,并且施工简便。

高分子絮凝剂在制革废水处理的实验研究

制革废水含有大量难降解的有机污染物及有毒有害物质,直接排放将严重影响生态环境与人类健康。文章以制革废水为研究对象,使用阳离子聚丙烯酰胺(C-PAM)絮凝剂处理制革废水,对处理工艺参数进行优化。通过试验,确定制革废水处理最佳工艺条件:阳离子聚丙烯酰胺(C-PAM)投加量为1.5 mg/L,调节废水的p H值为9,沉降时间约20 min,COD去除率最高为89.6%。

“Grafting from”法制备高载量大孔弱阳离子交换层析介质

针对大孔聚合物层析介质孔径大、比表面积低而导致的蛋白结合容量低的问题,采用“graftingfrom”策略,以大孔聚丙烯酸酯微球为基质,通过氧化还原引发甲基丙烯酸在微球表面接枝聚合,制备了高载量弱阳离子交换层析介质.研究了单体浓度、过硫酸钾浓度及反应温度等因素对蛋白结合容量的影响.所得介质的蛋白静态结合容量和动态结合容量分别达到252.21和157.25mg/mL;同时发现具有一定离子交换容量的该类介质能够在0.2 mol/L NaCl缓冲液中保持100 mg/mL的蛋白结合容量.将该层析介质用于鸡卵清中溶菌酶的纯化,获得了较高的纯化效率.

阳离子-π动态交联高性能聚芳吲哚醚酮的构筑

玻璃化转变温度(Tg)和热稳定性是聚合物重要的物理性能,影响了材料的应用领域。交联被认为是提高Tg和热稳定性的重要方法之一。本文以4,4-二氟二苯酮和4-羟基吲哚为单体,通过亲核取代反应成功制备了线型聚芳吲哚醚酮(PINEK),并通过简易的浸泡碱性水溶液的方式实现了PINEK的阳离子-π动态交联。与传统的线型聚醚醚酮(PEEK)和PINEK相比,交联型聚芳吲哚醚酮(C-PINEK)表现出较高的Tg(Tg=251℃)和优异的热分解温度(Td=501℃)。

压裂液用阳离子聚合物稠化剂的合成

针对压裂液稠化剂所存在的杂质含量较高、储层伤害较大、耐温抗盐性较差、耐剪切性不足等问题,以丙烯酰胺(AM)和二甲基二烯丙基氯化铵(DMDAAC)为单体,采用水溶液聚合法制备了压裂液用阳离子聚合物稠化剂,考察了反应条件对产物相对值分子量和阳离子度的影响。实验结果表明,优化合成条件为:单体总质量分数为40%,n(AM)∶n(DMDAAC)=3∶1,反应温度45℃,引发剂用量(与单体质量比)0.05%,pH值为7;在聚合物加量为0.8%时,基液黏度为80.1 mPa·s,交联后体系黏度可达335 mPa·s。