耐温抗盐聚合物PAMA的表征及溶液性能研究

合成了新型单体4-烯丙基庚烷基苯酚（AHP ）,然后以丙烯酰胺（AM）为主要原料、引入单体AHP,同时引入适量的2-丙烯酰胺基-2-甲基丙磺酸（AMPS）,采用水溶液自由基胶束聚合法合成了疏水缔合AM-AMPS-AHP三元共聚物（PAMA）。利用1H-NMR和FT-IR分别对AHP和PAMA进行表征。考察AHP加入量、聚合物浓度、NaCl浓度和温度对共聚物溶液黏度的影响。结果表明,引入AHP单体使共聚物具有优良的增黏和抗盐能力,含AHP（摩尔分数为1.0%）、质量浓度为1 500 mg/L的 PAMA溶液在53 ℃、20 000 mg/L NaCl盐水中的黏度达到178.6 mPa?s,在90 ℃、7 000 mg/L NaCl盐水中的黏度达到110.8 mPa?s,显示出良好的耐温、抗盐性能。     

Influence of Polyalkylmethacrylate VIIs on Boundary Film Formation,Friction,Wear and Efficiency of Lubricants

Polyalkylmethacrylates (PAMAs) are well-known as viscosity index improvers and dispersant boosters. This paper shows that PAMAs are able to adsorb from oil solution on to metal surfaces, to produce thick, viscous boundary films.These films enhance lubricant film formation in slow speed and high temperature conditions and thus produce a significant reduction of friction. A systematic study of this phenomenon has made use of the highly flexible nature of PAMA chemistry. A range of dispersant and non-dispersant polymethacrylates has been synthesized. The influence of different functionalities, molecular weights and architectures on both boundary film formation and friction has been explored using optical interferometry and friction-speed charting. From the results, guidelines have been developed for designing PAMAs having optimal boundary lubricating properties.Through their ability to form boundary films PAMAs can significantly contribute to reduce wear in engine, gear and hydraulic lubrication. As a consequence of their viscometric and tribological performance PAMAs can furthermore improve fuel and energy efficiency in different, namely engine and hydraulic applications.Extensive work is currently conducted in the lubricant industry to develop engine oils with lower sulfur, phosphorus and metal content (low SAPS) and to optimize their frictional properties through the use of friction modifiers or synthetic base stocks. We have investigated the contribution of PAMA viscosity index improvers and boosters to improve fuel economy and to reduce wear levels. This paper reports our efforts to develop a new range of PAMAs that have been optimized in terms of composition, architecture, molecular weight and functionality and which can be used in low viscosity, low SAPS formulations to help meet the stringent requirements of modern engine oils.     

Influence of Polyalkylmethacrylate VII on Boundary Film Formation,Friction,Wear and Efficiency of Lubricants

1 Influence of PAMAon Boundary Fil mFormation and Friction1.1 Experi mental methodsUltra-thin optical interferometry has been used tostudy thinlubricating fil ms for more than a decade and theexperi mental details of this technique have been reportedpreviously[1].The principle of the test setup is shown inFigure1.A polished steel ball is loaded and rolled againstthe flat surface of a glass disc that is coated with a thinsemi-reflecting chromiumlayer and a silica spacer of about500nmthickne…     

马氏漏斗黏度计测定钻井流体流变参数新方法的建立

目前使用马氏漏斗黏度计作为流变仪使用,所得到的数学模型计算过程繁琐、精度不足,无法满足现场测定钻井流体流变参数的需求。笔者针对牛顿型与非牛顿型钻井流体,优化了流量系数、壁面剪切速率、壁面剪切应力及流变曲线的数学模型,得到了测定牛顿黏度、表观黏度、塑性黏度以及动切力的新数学模型。结果表明,模型下矿物油、合成油、燃料油、绒囊冲洗液及甲酸盐钻井液的流变曲线与HAAKE MARS Ⅲ流变仪所测得的流变曲线之间存在很强的正相关性,相似度很高;模型下5种钻井流体的牛顿黏度、表观黏度、塑性黏度以及动切力的测量值与ZNN-6旋转黏度计的测量值之间的误差分别为1.40%、4.29%、2.78%与10.13%;说明了,建立的新方法可准确、简便地求得钻井流体的流变参数,计算准确度与ZNN-6旋转黏度计相符,可满足现场钻井流体流变学设计的需求。      

钻井液降黏剂SSMA的本体聚合制备与性能

为探究本体聚合法合成的磺化苯乙烯-马来酸酐（SSMA）在水基钻井液中降黏性能的优劣,以苯乙烯（St）、马来酸酐（MA）为原料,分别采用本体聚合和溶液聚合制得苯乙烯-马来酸酐（SMA）,磺化后制得SSMA,并对不同方法制得的磺化苯乙烯-马来酸酐（SSMA）在钻井液中的降黏效果和抗温抗盐性能进行评价。结果表明,2种方法合成的SSMA都可有效地拆散钻井液中黏土颗粒形成的空间网状结构,但在盐水和高温条件下2者表现出不一样的降黏效果。①在淡水基浆中,2者均表现出好的降黏效果,当加量达到0.75%时,本体聚合制得的SSMA在淡水基浆中降黏率可达95.38%,溶液聚合制得的SSMA在基浆中的降黏率为85.54%。②在盐水基浆中,与溶液聚合制备的SSMA相比,本体聚合制备的SSMA的降黏作用更强,具有更好的抗盐性能,当加量达到1%时,其降黏率可达53.33%。③在高温老化实验中,本体聚合制得的SSMA在基浆中的降黏性能较溶液聚合制得的SSMA受高温影响较小,在老化温度为230℃时,仍可保持40%以上的降黏率,具有更好的抗温性能。④在高密度基浆中,本体聚合法制备的SSMA具有较高的降黏率,220℃老化后降黏率仍在60%以上,高于溶液聚合法制备的SSMA在高密度基浆中47.45%的降黏率。      

New formula for acid fracturing in low permeability gas reservoirs: Experimental study and field application

One of the main stimulation techniques to enhance gas production in low permeability reservoirs is acid fracturing. Controlling the leak-off of reactive fluids is the key to a successful acid fracturing. In this study, new chemicals and techniques have been developed to control the leak-off by increasing the viscosity of the fluid systems after the acid fracturing fluids were injected into formations. The initial viscosity of the acid fluids was low. The viscosity increased with the increase in the amount of acid injected. Experiments have been conducted in laboratory to prove the efficiency of leak-off control using the new chemicals. The experimental results showed that the new fluid systems reduced the leak-off significantly compared to the gelled and normal acids. The leak-off rate of the new fluid systems was close to that of non-reactive fluids. Because the targeted reservoirs had a high temperature, the thermal stability was also tested and the results showed that the new chemical fluids were stable at 120 °C. Because of the remarkable experimental results, acid fracturing stimulations have been conducted using the new chemical fluid systems in 26 wells in Changqing gas field. The production performance has been evaluated after acid fracturing using the new chemicals. The field test results showed that the gas production was increased remarkably using the new chemical fluids and techniques, compared to the routine gelled acid fracturing. A plan has been embarked to apply the proposed techniques in Changqing gas field widely because of the satisfactory pilot field test results and the low cost of the chemicals.     

基于含硅类增稠剂的新型超临界CO2压裂液的流变特性及岩心伤害评价

针对超临界CO2压裂液黏度低、携砂能力差的应用现状合成了含硅类增稠剂,并研究了超临界CO2压裂液的流变特性及岩心伤害情况,旨在为增稠剂的优选以及现场压裂施工提供参考依据。通过溶液聚合法室内合成了聚甲基倍半硅氧烷PMSQ和聚甲基倍半硅氧烷-醋酸乙烯酯PMSQ-VAc二元共聚物增稠剂,采用红外光谱测试验证了增稠剂样品的主要官能团,运用高压长管管流实验法测试了超临界CO2压裂液的增黏效果及其流变特性,最后评价了超临界CO2压裂液在人造裂缝天然长岩心中的滤失性、岩心伤害率。研究结果表明,随着温度、压力的升高,2种增稠剂的增黏效果均先增大后减小;随着增稠剂注入量的增大,2种CO2压裂液的黏度先增大后减小;在超临界CO2流体中,PMSQ-VAc的增黏效果相对较好,可使其黏度最大达到3.892 mPa·s;在渗透率为0.551 mD的岩心中,PMSQ-VAc与超临界CO2流体混合后压裂液的滤失系数为1.435×10-2 m/min1/2,滤失速度为0.010 m/min,岩心的伤害率为16.33%~25.36%,滤失系数和滤失速度较小,伤害程度属弱。     

基于含硅类增稠剂的新型超临界CO2压裂液的流变特性及岩心伤害评价

针对超临界CO₂压裂液黏度低、携砂能力差的应用现状合成了含硅类增稠剂,并研究了超临界CO₂压裂液的流变特性及岩心伤害情况,旨在为增稠剂的优选以及现场压裂施工提供参考依据。通过溶液聚合法室内合成了聚甲基倍半硅氧烷PMSQ和聚甲基倍半硅氧烷-醋酸乙烯酯PMSQ-VAc二元共聚物增稠剂,采用红外光谱测试验证了增稠剂样品的主要官能团,运用高压长管管流实验法测试了超临界CO₂压裂液的增黏效果及其流变特性,最后评价了超临界CO₂压裂液在人造裂缝天然长岩心中的滤失性、岩心伤害率。研究结果表明,随着温度、压力的升高,2种增稠剂的增黏效果均先增大后减小;随着增稠剂注入量的增大,2种CO₂压裂液的黏度先增大后减小;在超临界CO₂流体中,PMSQ-VAc的增黏效果相对较好,可使其黏度最大达到3.892 mPa·s;在渗透率为0.551 mD的岩心中,PMSQ-VAc与超临界CO₂流体混合后压裂液的滤失系数为1.435×10-2 m/min1/2,滤失速度为0.010 m/min,岩心的伤害率为16.33%~25.36%,滤失系数和滤失速度较小,伤害程度属弱。      

耐高温低碳烃无水压裂液室内研究

针对目前国内低碳烃无水压裂液耐温能力差的问题,用戊烷、磷酸酯胶凝剂LPEA-1和黏度促进剂FS-1配制了耐高温低碳链烃无水压裂液（戊烷基Frac-H压裂液）,并对其性能进行了初步评价。通过室内试验研究,确定戊烷基Frac-H压裂液的基本配方为95.8%戊烷+2.0% LPEA-1+2.2% FS-1,按此配制的压裂液在180 s后黏度达到最大;在温度为130℃、剪切速率为170 s-1条件下连续剪切120 min后的黏度大于50 mPa·s;破胶时不需加入破胶剂,且破胶液无残渣;戊烷基Frac-H压裂液对页岩储层的伤害稍大于致密性储层,但显著低于水基压裂液对页岩岩心的伤害。研究结果表明,用戊烷、磷酸酯和黏度促进剂配制的戊烷基Frac-H压裂液,可以满足非常规储层高温油气井压裂施工对压裂液性能的要求。      

新型油基降滤失剂FCL的研制及评价

采用α-烯烃与苯乙烯乳液聚合的方法,利用乙酸酐与浓硫酸进行适度磺化,得到一种亲白油的高分子量聚合物,这种高聚物经过进一步氢化反应,制得一种油基钻井液降滤失剂FCL,其在白油中以胶体形式出现,不会破坏钻井液性能,同时这种胶体尺寸能封堵泥饼中的孔隙,从而达到降滤失的效果。性能评价结果表明,其最佳加量为1.5%,在180℃、3.5 MPa的高温高压滤失量为8.4 m L,优于国外同类产品phlips D21;在密度低于1.5 g/cm3时,油基降滤失剂FCL对油基钻井液的流变性影响较小,在高密度油基钻井液中,表现出更高的降切性能,可使密度为2.0 g/cm3的油基钻井液动切力维持在15 Pa以下。     

钻井液马氏漏斗黏度与表观黏度的关系

马氏漏斗黏度和表观黏度在钻井流体性能表征上均有其重要作用,但对于它们的相互关系目前尚未有明确的结论.为此,基于漏斗黏度测定原理,探讨钻井流体在漏斗中流出的全过程,建立马氏漏斗黏度和表观黏度之间的关系式,采用室内配制钻井流体的测定结果,证实所建关系式的可靠性.结果表明,钻井流体的漏斗黏度反映了随漏斗剪切速率变化的表观黏度;当已知钻井流体的马氏漏斗黏度时,可用漏斗黏度与表观黏度的关系式估算其表观黏度,计算结果可靠,为钻井流体表观黏度和漏斗黏度的应用提供了方便.     

新型高温高密度盐水钻井液研究

针对中国高温高密度盐水钻井液普遍存在的"使用处理剂种类过多,加量过大,钻井液老化后HTHP造壁性和流变性难以控制,配制成本和维护成本居高不下"的难题,分析长期攻关而至今没能很好解决的原因,在此基础上提出了"以利用钻井液中处理剂高温交联作用为基础,结合使用优化重晶石级配以解决高密度钻井液黏度高、HTHP失水量大、且性能很难调控的难题,综合形成了高温高密度盐水钻井液研究"新的技术路线,并由此研发出性能好（HTHP失水量低,流变性良好……）而处理剂种类少（共4种）、总用量大幅度降低（仅为现用量的1/2~1/3）的高温高密度盐水钻井液体系,而且具有高温条件下使用性能越来越好,性能维护方便的潜力和趋势,为有效解决中国高温高密度盐水钻井液多年未能很好解决的技术难题,提供一条可行的途径。      

Application of silica (SiO2) nanofluid and Gemini surfactants to improve the viscous behavior and surface tension of water-based drilling fluids

Further studies into drilling fluids especially to reduce the use of oil and synthetic-based drilling fluids are ever-growing due to their contributions to environmental pollution. This study, therefore, attempts to evaluate the thermal, viscosity, surface tension, and filtration loss properties of water-based drilling fluids (WBDFs) upon the addition of Gemini surfactant-silica nanofluid. This surfactant-nanofluid was formed by dissolving silica nanofluid in the surfactant solution, and ultra-sonication was used to attain homogeneity. Characterization of the Gemini surfactant-silica (SiO₂) nanofluid was done by Fourier Transform Infrared Spectroscopy (FTIR). The viscosity, surface tension, and filtration loss properties were studied using the rheometer, tensiometer, and low-pressure, low-temperature (LPLT) filter press respectively. The experimental results showed that Gemini surfactants contributed to the highest increase in drilling fluid viscosity compared to a conventional surfactant. Also, when combined with silica-nanoparticles showed better thermal stability with an 11% average change in viscosity with increasing temperature and a decrease in surface tension and filtration loss both showing a 17% and 12% decrease respectively.     

压裂液破胶效果对支撑剂回流影响的实验研究

川西浅层蓬莱镇组气藏地层温度低,容易出现压裂液破胶不彻底的情况,压后排液时常常导致支撑剂的回流返吐。研究压裂液破胶效果对支撑剂回流的影响规律,确定一个合适的破胶液粘度,对于压裂液配方优化调整具有重要的现实意义。文章对压裂液破胶效果与支撑剂回流返吐的影响关系作了详细的实验评价,证实破胶液粘度的临界点为10mPa.s,破胶液粘度低于10mPa.s时基本上不会对支撑剂回流产生影响。     

基于马氏漏斗黏度的油基钻井液表观黏度预测方法

为了研究油基钻井液漏斗黏度与表观黏度之间存在的联系，从马氏漏斗黏度计的结构出发，在水基钻井液研究成果的基础上，分析了油基钻井液在马氏漏斗黏度计中的流动规律，研究了利用油基钻井液马氏漏斗黏度预测表观黏度的可行性，推导了流体漏斗黏度计算公式，建立了油基钻井液马氏漏斗黏度与表观黏度函数之间的数学模型，并对该模型分别进行了室内试验和现场试验的验证。试验结果显示，室内和现场计算的表观黏度与实测表观黏度的最大相对误差分别为6.8%和8.2%，均在合理范围内；现场试验中，油水比从70:30增大到91:9，预测结果没有受到影响。研究结果表明，基于马氏漏斗黏度的表观黏度预测模型能够较准确地估测油基钻井液的表观黏度，钻井现场可以利用油基钻井液的马氏漏斗黏度估算其表观黏度，这为现场预测油基钻井液的表观黏度提供了方便。      

压裂液悬砂及支撑剂沉降机理实验研究

压裂液的携砂性能优劣直接影响着支撑剂在裂缝中的输送铺置效果及压后裂缝的有效导流能力。研制了“XS-I型”压裂液悬砂及支撑剂沉降物理模拟实验装置;开展了3种陶粒支撑剂（70/140目、40/70目、30/50目）在SRFP-1型压裂液中的悬砂特性研究,分析了支撑剂在携砂液中的沉降量、沉降速率以及二者随沉降时间的变化规律,得出影响压裂液悬砂性能的主控因素。实验研究表明,携砂液中支撑剂沉降分为快速沉降、缓慢沉降、稳定平衡3个阶段。压裂液黏度是影响压裂液悬砂性能的最主要因素,其次是支撑剂粒径、携砂液砂比。低黏度压裂液仅对70/140目支撑剂有一定悬浮能力（支撑剂充分沉降时间10～20 min）,对40/70目和30/50目的支撑剂悬浮性能较差（支撑剂充分沉降时间仅为1.0 min～5.5min）,整体悬砂能力较差。中黏度压裂液对70/140目支撑剂悬浮效果好（仅有9.9%～11.1%的支撑剂沉降）,在小于15%砂比下对40/70目及30/50目支撑剂有较好的悬浮能力（支撑剂充分沉降时间80 min～240 min）。中高黏度压裂液中,大粒径（30/50目）支撑剂在高砂比（25%～30%）条件下加入,也仅有12%～13.1%的支撑剂沉降,悬砂性能优,适宜作为主加砂阶段的携砂液。研究结果丰富了压裂液悬砂能力测试方法及支撑剂优选评价手段,为压裂液、压裂施工参数的优化及支撑剂的优选,提供基础数据依据。      

新型固井冲洗液评价装置适用性分析

为了明确新型固井冲洗液评价装置的适用范围,根据评价装置内筒外壁面处与固井环空壁面剪切速率相等的原理,结合罗伯逊-斯蒂夫流变模式推导了冲洗液为牛顿、宾汉和幂律流体时其在内筒外壁处剪切速率的计算公式,并分析了不同流变模式冲洗液内筒外壁面处剪切速率与固井环空壁面剪切速率的误差。分析结果为:当冲洗液为牛顿流体时,评价装置在内筒外壁面处的剪切速率与固井界面处相等,不存在理论误差;当冲洗液为宾汉和幂律流体时,评价装置内筒外壁面处的剪切速率大于固井界面处,且剪切速率增量与内外筒间隙和冲洗液流变性质有关;当评价装置外内筒半径比限定在1.04~1.20时,冲洗液为幂律流体且流性指数大于0.6或为宾汉流体且动塑比小于1 Pa/（mPa·s）时,剪切速率相对误差在10%以内。研究结果表明,评价装置外内筒半径比越小,相对误差越小,其适用范围越大。      

高粘度复合变性淀粉的流变性与降滤失性能

以马铃薯淀粉和氯乙酸为主要原料,通过交联-醚化制备了高粘度复合变性淀粉(CM-CMS),考察了高粘度CM-CMS糊液的流变性能及其在钻井液中的降滤失性能,探讨了其降滤失机理。结果表明:CM-CMS糊液表现为假塑性流体特征;其在饱和盐水钻井液及4%盐水钻井液中的增粘、降滤失性能明显优于中粘羧甲基纤维素钠(MV-CMC),在淡水钻井液中与MV-CMC接近。     

流动模拟器在测定原油乳状液粘度中的应用

简要叙述了用流动模拟器(FLOWSIMULATOR)测定密闭、带压体系粘度的可行性 ,并进行低粘度的、高粘度的实液和原油乳状液的粘度测量 ,实验结果表明利用流动模拟器能够准确地测定上述流体的粘度。同时 ,给出了原油乳状液管输的沿程摩阻 (f)。     

A generalized rheological model for shear thinning fluids

A generalized rheological model for shear thinning fluids has been developed. The new model relates shear stress to shear rate for this type of fluids and predicts the behaviour of hyperbolic, parabolic, elliptic, and Newtonian fluids with or without yield stress at one or both extremes of the shear rate. It correlates the shear stress to the shear rate for a variety of drilling fluids better than both the power-law and Hershel-Bulkley model. It can also predict the viscosity of these fluids. The shear stress and viscosity are required for pressure drop calculations of flow in pipes, annuli, and packed beds.