Synthesis and evaluation of an oil-soluble viscosity reducer for heavy oil

To reduce the viscosity of highly-viscous oil of the Tahe oilfield （Xinjiang,China）,an oilsoluble polybasic copolymer viscosity reducer for heavy oil was synthesized using the orthogonal method.The optimum reaction conditions are obtained as follows：under the protection of nitrogen,a reaction time of 9 h,monomer mole ratio of reaction materials of 3：2：2 （The monomers are 2-propenoic acid,docosyl ester,maleic anhydride and styrene,respectively）,initiator amount of 0.8% （mass percent of the sum of all the monomers） and reaction temperature of 80 oC.This synthesized viscosity reducer is more effective than commercial viscosity reducers.The rate of viscosity reduction reached 95.5% at 50 oC.Infrared spectra （IR） and interfacial tensions of heavy oil with and without viscosity reducer were investigated to understand the viscosity reduction mechanism.When viscosity reducer is added,the molecules of the viscosity reducer are inserted amongst the molecules of crude oil,altering the original intermolecular structure of crude oil and weakening its ability to form hydrogen bonds with hydroxyl or carboxyl groups,so the viscosity of crude oil is reduced.Field tests of the newly developed oil-soluble viscosity reducer was carried out in the Tahe Oilfield,and the results showed that 44.5% less light oil was needed to dilute the heavy oil to achieve the needed viscosity.

Study on Viscosity Reducing and Oil Displacement Agent for Water-Flooding Heavy Oil Reservoir

In the process of water-flooding development of heavy oil reservoir,due to the high viscosity and oil-water mobility ratio of heavy oil,there are some problems such as poor fluidity,high residual oil saturation and low recovery efficiency,which seriously restrict the efficient development of heavy oil.The molecular structure characteristics of asphaltenes and resins in heavy oil were analyzed.Based on the three most concerned properties of chemical agents,including the emulsification performance,the interface performance and the oil washing performance,three chemical oil displacement agents for heavy oil reservoirs were developed,and the structure of the chemical agents were characterized by high resolution mass spectrometry.The performance evaluation of chemical agents and core displacement experiments show that there is no obvious correlation between the properties of chemical agents,including interfacial tension,emulsifying ability and oil washing ability.For heavy oil reservoirs,the emulsification and viscosity reduction performance of chemical agents was more important than the oil washing capacity,and the oil washing capacity was more important than the interface performance.Viscosity reduction performance was the key parameter of oil displacement agent suitable for heavy oil reservoir.The composite binary system consisting of the viscosity reducer and the polymer had better oil recovery than using viscosity reducer alone.

Effect of Continuous Phase Viscosity on Membrane Emulsification

Oil-in-water(o/w) emulsions were produced with a membrane emulsification system. The effect of the continuous phase viscosity on the emulsification was studied. The theoretical analyses show that the continuous phase viscosity influences not only the flow field of the continuous phase but also the interfacial tension. The droplet size distribution and disperse phase flux for different continuous phase viscosity were investigated experimentally at constant wall shear stress and constant volume flow rate of the continuous phase respectively.

Measurement of Viscosity Alteration for Emulsion and Numerical Simulation on Bitumen Production by SAGD Considering In-situ Emulsification

A thermal steam stimulation process, such as steam-assisted gravity drainage （SAGD）, induces water-in-oil emulsion of heavy oil or bitumen throughout the production. The present study investigated the effects of in-situ emulsification in the oil sands reservoir for SAGD process. The viscosities of water-in-oil emulsions produced were measured with respect to water-oil ratio （W/O）, shear rates, pressures and temperatures. The results therefore were employed to develop the numerical model of viscosity alteration. Numerical simulations of the SAGD bitumen production considering viscosity alteration were also carried out to investigate distribution characteristics of emulsion, water, and bitumen at steam chamber boundary and effects of in-situ emulsification on bitumen production behavior. With a model named SAGD-Emulsion Model, it was found that the net recovery factor of bitumen for this model is 5 to 10% higher than that of conventional SAGD simulation. Ultimately, it was found that the recovery factor of bitumen increased with W/O of emulsion generated in the reservoir since higher water content would invariably allow bitumen to flow at higher relative permeability, while the increase in viscosity merely delayed bitumen production.

The Viscosity-reducing Mechanism of Organic Wax Additive on CRMA

CRMA was prepared by mixing PG 64-22 asphalt with crumb rubber powder of 40 mesh size and 18% by weight of the asphalt. Sasobit, a typical organic wax additive, was selected and added into CRMA. A series of tests, namely, brookfield viscosity, environmental scanning electron microscope（ESEM）, component test, differential scanning calorimeter（DSC）, fourier transform infrared spectroscopy （FTIR） and nuclear magnetic resonance （NMR） were conducted on CRMA with and without organic wax additive, and microcosmic appearance, component content and molecular structure of various asphalt binders were obtained. The test results indicate that the addition of Sasobit~ into CRMA can effectively change the contents of components： the content of asphaltenes increases relatively, while saturates decreases. In addition, the interaction between various components of CRMA is weakened, and the state of equilibrium between the dispersant and dispersed phase is changed at the same time. That is why the viscosity decreases after the organic wax additive is added into CRMA.

Analysis of the rates of emulsification in intraocular silicone oil tamponades of differing viscosities

AIM:To investigate the rates of emulsification in silicone oil(SO)tamponades of differing viscosities used during pars plana vitrectomy(PPV)in the treatment of complicated vitreoretinal diseases.METHODS:This study was a prospective randomized clinical trial.Totally 290 cases with greater likelihoods of secondary detachment were included and randomly grouped into either Siluron 2000(n=143)or Siluron 5000(n=147)SO tamponades with 23-gauge PPV.Patient followups and data analyses were conducted 1,3,6,and 12 mo post-surgery.RESULTS:The time of the SO emulsification ranged from 1 to 17 mo,with a mean of 7.3±4.2 mo.The Siluron 5000 group showed a slower emulsification rate in comparison to the Siluron 2000 group.The Siluron 2000 group took a shorter time to show signs of emulsification,necessitating earlier SO removal.However,there were no significant differences in the occurrence of complications,including secondary retinal detachment,cataract,corneal abnormality,high intraocular pressure and hypotony.CONCLUSION:The Siluron 2000 SO tamponade shows a faster rate of emulsification than the Siluron 5000 SO,necessitating earlier removal.Both groups show similar results in terms of anatomical success and visual acuity outcome,and there is no significant difference between the SOs regarding the occurrence of complications.

Development and application of polymetric surfactant emulsification and viscosity reduction system

Compounding polymer AP-P4 with high viscosity-reducing Gemini Surfactant HD,which is used as an emulsifier viscosity reduce,to improve the stability of the O/W emulsion while the viscosity reduction rate is kept.A polymeric surfactant emulsification and viscosity reduction system capable of forming a relatively stable O/W emulsion of heavy oil(0.5%HD+0.1%AP-P4)is then compounded.The system has been characterized as a high viscosity reduction rate and high stability.Meanwhile,the production liquid does not need to be added with a demulsifier and only needs to be heated to 70°C to achieve effective demulsification.The influencing factors of the performance of the polymetric surfactant emulsification and viscosity reduction system were studied.When the oil-water ratio was 70:30 and 60:40,the viscosity reduction rate was 97.47%and 99.09%,respectively;after 15 h at 30°C,the dehydration rates were 95.8%and 99.2%,respectively.The dehydration rate after 15 h at 70°C was 98.1%and 99.4%,respectively;at 30∼50°C,the water phase temperature has a greater impact on the viscosity;at 60°C,70°C,the water phase temperature has little effect on the viscosity;as the temperature of the aqueous phase increased,the stability of the emulsion deteriorated.When the aqueous phase temperature was 30°C,50°C and 70°C,the dehydration rates of the emulsion after 15 h were 95.8%,96.7%and 98.1%,respectively;As the degree of mineralization increases,the viscosity reduction rate decreases,and the stability of the emulsion deteriorates.The system has been used in field test for 2 injection wells,and the production rate of the two wells increased with a peak value of 25 m3/d and 20 t/d,respectively.

稠油化学复合冷采技术研究与应用

我国稠油储量可观,其中60%的是深层稠油,而主流的蒸汽吞吐等热采技术采收率不足20%;稠油资源开发潜力极大,积极探索新的开采方式以提高采收率是石油领域高质量发展的必然选择。本文着重阐述稠油化学复合冷采技术体系构建及其现场应用,为中深层稠油的新型绿色低成本接替技术发展提供有效方案。在分析稠油组分的基础上,细致剖析稠油结构致黏机理,包括化学降黏机理、降低启动压力梯度机理、提高驱油效果机理在内的提高采收率机理,以丰富理论认识。面向工程应用亟需,从水溶性降黏剂分子设计与合成、自组装调堵剂研发两方面出发,突破稠油绿色化学驱油体系。基于发展的稠油化学复合冷采技术,完成了3个稠油油田示范工程应用,在提高产油量、控制含水率方面取得了良好成效。进一步梳理了分子采油理论与技术、渗流理论与数值模拟技术等方面的后续发展要点,以为深层稠油的绿色高效开发接替技术研究、稠油化学复合冷采技术推广应用研究等提供启发和参考。

分离多环芳烃用于超稠油掺稀降黏的研究

针对炼油厂催化裂化柴油大量过剩和芳烃含量过高等问题,结合稠油掺稀降黏开采掺稀比高、稀油资源紧缺的现状,从催化裂化柴油中萃取分离多环芳烃,用于超稠油掺稀降黏研究。对多环芳烃萃取进行正交试验,在筛选出的最佳操作条件(萃取温度为45℃、萃取时间为5 min、相分离时间为5.5 min和剂油体积比为1.4)下,多环芳烃产品收率为29.87%、芳烃质量分数高达99.07%。在掺稀比均为0.10时,多环芳烃和塔河稀油的掺稀降黏量率分别为94.20%和68.58%。拟合计算结果表明,多环芳烃用量仅为塔河稀油的16.32%时,即可达到塔河油田稠油掺稀降黏要求。以塔河油田稠油自喷井为例,当稠油含水率分别为0,30%和50%时,掺入多环芳烃相对掺入稀油的单井日产油增长率分别达到115.90%,84.57%,62.20%。

克拉玛依油砂沥青油溶性降黏剂的制备及性能评价

以甲基丙烯酸十八酯、N-苄基马来酰亚胺和丙烯酰胺为原料合成了针对于克拉玛依油砂沥青的新型油溶性共聚降粘剂。对单体配比、引发剂用量、反应温度等影响条件进行了优化,探究了降黏剂用量和温度等因素对降黏效果的影响。确定了该降黏剂的聚合反应条件为:聚合单体摩尔比为10∶4∶3,引发剂用量为单体总质量的1.0%,反应温度为85℃。在降黏剂添加量1000 mg·kg^(-1),反应温度50℃,反应时间60 min时降黏效果最好,在此条件下的降黏率为35.7%。

油溶性降黏剂SVM的合成及降黏机理探究

以甲基丙烯酸十八烷基酯(SMA)、4-乙烯基苯甲酸(VBA)和顺丁烯二酸酐(MA)为单体,合成一种能有效降低新疆克拉玛依稠油黏度的油溶性降黏剂(SVM)。通过单因素实验得到SVM降黏率最高为60.55%,红外和核磁分析结果证明了SVM的成功合成。通过对加入降黏剂前后的稠油体系进行分子动力学模拟发现,降黏剂主要分散了稠油中沥青质组分;进一步通过SEM、EDS和AFM探究SVM对沥青质分散情况发现,SVM降黏剂能有效破坏沥青质致密的堆叠结构,抑制沥青质聚集。稠油体系模拟得到的氢键数目从98个/帧增长到143个/帧。实验和模拟结果表明,氢键数目变化协同苯环共轭能力的增强能有效破坏沥青质的聚集,降低稠油黏度。

热复合驱中热、降黏剂、气体对原油黏度的影响

为了研究热、降黏剂、气体单独对原油黏度影响,以黏度、降黏率为指标,通过高温高压流变仪研究了复合驱中热、降黏剂、气体对原油黏度的影响规律。结果表明,升高温度是降低原油黏度的最有效方式,在一定压力范围内,N2对降低原油黏度起负作用,CO_(2)对降低原油黏度起正作用,降黏剂与CO_(2)可协同作用降低原油黏度。

抗220℃高温两性离子聚合物降黏剂的制备与性能

针对当前高温高密度水基钻井液流变性调控难题,基于分子结构优化设计和单体优选,制备了新型抗高温两性离子聚合物降黏剂HP-THIN。通过正交实验与单因素实验相结合的方法,对HP-THIN的制备条件进行了优化。采用红外光谱仪、乌氏黏度计和热重分析仪等分别对HP-THIN的分子结构、热稳定性以及相对分子质量进行表征和测定,研究了HP-THIN在220℃超高温条件下对淡水浆、盐水浆、含钙浆和高密度复合盐水浆等不同类型钻井液基浆的降黏性能。在室温下,测试了HP-THIN对基浆黏土颗粒吸附能力、Zeta电位和粒径的影响,并与国内外同类产品(Polythin和xy-27)进行了对比。结果表明,合成降黏剂HP-THIN的反应温度为60℃,反应时间为3 h,引发剂用量和链转移剂用量均为反应单体总量的1%,单体总质量分数为30%;单体AM、AA、AMPS、PTM物质的量比为1.9∶7.5∶2.1∶1。该聚合物的分子结构中含有设计官能团,其黏均相对分子质量约为8211,且具有较好的热稳定性。220℃老化后,HP-THIN在最优加量(0.3%)下对淡水基浆、盐水基浆、含钙基浆和高密度复合盐水基浆的降黏率分别达86%、72%、73%和51%,HP-THIN对不同类型钻井液基浆的高温降黏效果均优于国内外同类产品,相对于xy-27和Polythin,降黏剂HP-THIN对基浆黏土吸附能力强、Zeta电位绝对值大、黏土颗粒尺寸小,可以更好地消除黏土颗粒间网状结构,降低钻井液黏度,具有良好的应用前景。

纳米N-A降黏剂的制备及性能评价

针对普通纳米降黏剂对特稠油降黏效果差、洗油效率低等问题,制备了纳米N-A降黏剂,采用FTIR,TEM等方法表征了降黏剂的微观结构,考察了降黏剂的降黏效果、界面张力以及洗油效率。实验结果表明,纳米N-A降黏剂组成为:50%(w)纳米二氧化硅溶胶+40%(w)分散剂EB-1+4.2%(w)表面修饰剂+5.8%(w)增效剂。该降黏剂分散性能良好,粒径分布在20~60 nm之间,在降黏剂含量为1%(w)、油水质量比为7∶3、200℃,矿化度为0,8829.26 mg/L条件下老化48 h,特稠油降黏后黏度分别为6280,7213 mPa·s,降黏率分别达到83.77%,81.36%,降黏性能保持率分别为96.80%,95.39%。50℃下静置90 d后降黏性能保持率大于90%,可降低油水界面张力至0.076 mN/m,乳化液滴最大粒径9.5μm,洗油效率为30.9%,相对普通降黏剂,驱油效率提高22.3百分点。

抗裂降黏剂对硅粉抗冲磨混凝土性能提升研究

【目的】高强度硅粉混凝土普遍存在黏度高,施工难度大,开裂风险高等问题,严重影响泄水建筑物抗冲磨混凝土使用性能,因此抗冲磨混凝土设计要同时兼顾抗冲磨性能、施工性能和抗裂性能。【方法】前期通过复配膨胀组分、降黏组分和其他助剂研制了新型的混凝土抗裂降黏剂,以新疆某水利枢纽工程为对象,研究了抗裂降黏剂对不同强度等级硅粉抗冲磨混凝土的工作性、力学、变形、抗裂、抗冲磨等性能的影响,以综合评价其对硅粉抗冲磨混凝土性能改善效果。【结论】结果表明:抗裂降黏剂可用于配制C_(90)55、C_(90)50、C_(28)40不同强度等级的抗冲磨混凝土,且可显著改善硅粉抗冲磨混凝土的施工性能和抗裂性能。【结果】7%抗裂降黏剂的掺入,对混凝土坍落度、含气量、凝结时间影响不大,但可使C_(90)55、C_(90)50、C_(28)40硅粉混凝土拌合物塑性黏度减小64%~76%、屈服剪切应力减小26%~36%。相比于“硅粉”混凝土,“硅粉+抗裂降黏剂”混凝土收缩变形减小,至110 d龄期自生体积变形自始至终表现为“膨胀”,平板试验中单位面积上总开裂面积减小63%~83%,混凝土抗裂性能明显改善。此外,抗裂降黏剂的掺入,有利于提高混凝土内部密实度,可使混凝土抗压、抗拉强度略有提高,水下钢球法抗冲磨强度提高14%~40%。

生物柴油基减阻剂研制及滑溜水压裂液体系构建

为了解决常规白油基滑溜水体系在运输过程中容易分层以及减阻剂溶解太慢、对环境污染大等问题,首先通过测试不同相对分子质量及水解度的减阻剂F1~F6的溶解性和增黏性能优选了减阻剂F4;通过对稠化剂、分散剂及固液比筛选,研制了配方为34.0%生物柴油+3.0%稠化剂F-120+3.0%分散剂S-85+60.0%减阻剂F4的生物柴油基悬浮减阻剂,并将生物柴油基悬浮减阻剂与助排剂、防膨剂构建变黏滑溜水压裂液体系。实验结果表明,减阻剂F4在180℃下恒温剪切2 h后的表观黏度保留率为33.0%,热稳定性较好;变黏滑溜水压裂液具有良好的抗剪切能力和抗温性能,在剪切速率为170 s^(-1)下长期剪切后,常温下黏度保留率均可达90%以上,90℃下黏度保留率均达50%以上,其中高黏滑溜水压裂液黏度保留率可高达70%以上,低黏滑溜水压裂液的减阻率可达70%以上;高黏滑溜水压裂液的携砂性能比低、中黏滑溜水压裂液的高,且沉降速率最低,为0.005272 m/min。变黏滑溜水压裂液破胶后表面张力均小于27 m N/m,与煤油间的界面张力均小于2.0 mN/m,破胶液黏度均小于5.0mPa·s,且残渣含量均小于50 mg/L,满足标准要求。

黏重黑土条件下马铃薯收获机挖掘装置设计与试验

针对东北地区黏重黑土条件下马铃薯收获机工作阻力大、挖掘铲寿命短、挖掘质量难以保证等问题,将双行升运链式马铃薯收获机挖掘装置改进并设计一种分离式防堵马铃薯挖掘装置。采用理论分析研究方法,解析马铃薯收获机关键部件挖掘铲挖掘过程,探明影响马铃薯收获机挖掘铲工作阻力的主要影响因素;结合黏重黑土条件下马铃薯收获的农艺要求,以行驶速度、铲面铲宽和铲面倾斜角度为试验因素,以挖掘铲最大工作阻力和土壤最大压缩力为试验指标,进行多因素正交仿真试验,设计得出,挖掘铲在保证良好碎土效果且不造成马铃薯损伤的最佳参数,即行驶速度1.11 m·s^(-1),铲面铲宽150 mm,铲面倾斜角度30°时,挖掘铲最大工作阻力为566 N,土壤最大压缩力为152 N。田间验证试验表明,各项指标达到要求且均优于改进前整片式挖掘铲马铃薯收获机。

疏水缔合聚合物乳化性能及分相特征

配制了不同的疏水缔合聚合物(HAP),分析了HAP含量、疏水单体含量和油相含量对于聚合物乳化性能的影响,探讨了连续相中疏水缔合结构与油滴的相互作用规律。实验结果表明,HAP乳化时,油滴与连续相中的缔合结构相互作用,形成新的分子链间网络节点,构成了新的三维网络结构,使乳状液增黏。HAP的乳化增黏幅度由连续相与分散相的性质共同决定,其中,HP-1乳状液表观黏度最高增幅为36%。随着HAP中疏水单体含量的增加,乳化增黏幅度逐渐上升;HAP含量一定时,随油相含量增大,HAP乳状液乳化增黏幅度先增大后稳定、稳定性增强,但富集相体积存在最大值。HAP乳化性能及分相特征取决于连续相中的疏水缔合结构与油滴相互作用。

稠油化学降黏剂研究进展与发展趋势

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