Study on the in situ desulfurization and viscosity reduction of heavy oil over MoO_(3)–ZrO_(2)/HZSM-5 catalyst

Heavy oil is characterized by high viscosity.High viscosity makes it challenging to recover and transport.HZSM-5,MoO_(3)/HZSM-5,ZrO_(2)/HZSM-5 and MoO_(3)–ZrO_(2)/HZSM-5 catalysts were developed to promote in situ desulfurization and viscosity reduction of heavy oil.The physical and chemical properties of catalysts were characterized by XPS,XRD,TEM,NH3-TPD,etc.The effects of temperature,catalyst type and addition amount on viscosity and composition of heavy oil were evaluated.The results showed that the presence of MoO_(3)–ZrO_(2)/HZSM-5 nanoparticles during aquathermolysis could improve the oil quality by reducing the heavy fractions.It reduced viscosity by 82.56%after the reaction at 280℃ and catalyst addition of 1 wt%.The contents of resins and asphaltic in the oil samples were 5.69%lower than that in the crude oil.Sulfur content decreased from 1.45%to 1.03%.The concentration of H2S produced by the reaction was 2225 ppm.The contents of sulfur-containing functional groups sulfoxide and sulfone sulfur in the oil samples decreased by 19.92%after the catalytic reaction.The content of stable thiophene sulfur increased by 5.71%.This study provided a basis for understanding the mechanism of heavy oil desulfurization and viscosity reduction.

Synthesis of Hierarchical Porous Fe_(2)O_(3)/Al_(2)O_(3) Materials and Study on Catalytic Viscosity Reduction of Heavy Oil

Fe_(2)O_(3) nanoparticles were first dispersed in a sol solution containing an aluminum component introduced by an initial doping method.Composite catalyst Hierarchical Porous Fe_(2)O_(3)/Al_(2)O_(3) materials(HPFA)were then synthesized through a sol-gel method via phase separation.The performance of HPFA was compared with that of Fe_(2)O_(3) nanoparticle catalysts.The structure of the composite catalyst was characterized by scanning electron microscopy,X-ray diffraction,N_(2) adsorption/desorption,and crush strength testing.The results showed that the Fe_(2)O_(3) nanoparticles could be loaded into the porous skeletons of Hierarchical Porous Al_(2)O_(3) materials(HPA)to achieve a uniform dispersion while avoiding agglomeration,which improved the mechanical strength of the porous materials significantly.The HPFA was then used as a catalyst in the hydrothermal viscosity reduction process of Tuha heavy oil,and the viscosity reduction was investigated.The viscosity reduction rate of HPFA was 81%,which was better than that of the Fe_(2)O_(3) nanoparticles(56%)and HPA(47%).

Enhancing Heavy Crude Oil Flow in Pipelines through Heating-Induced Viscosity Reduction in the Petroleum Industry

The process of transporting crude oil across pipelines is one of the most critical aspects of the midstream petroleum industry.In the present experimental work,the effect of temperature,pressure drop,and pipe diameter on the flow rate of heavy crude oil have been assessed.Moreover,the total discharge and energy losses have been evaluated in order to demonstrate the improvements potentially achievable by using solar heating method replacing pipe,and adjusting the value of the initial pressure difference.Crude oil of API=20 has been used for the experiments,with the studied pipelines sections connecting the separator unit to the storage tank operating at a temperature of 25℃-100℃,pressure drop of 3,4,5,and 6 kg/cm^(2),and with pipe diameter of 4,6,and 8 in.The results show that on increasing the temperature and/or the pressure drop,the flow rate through the pipeline becomes higher,thus raising the total pumping energy(as the pipe diameter increase),while energy losses increase from the last separator to the storage tank in the field.A pipe diameter increase can also produce a growth of the total pumping energy(i.e.,energy losses increase).The results of the present analysis suggest that employing an optimal temperature(50℃)is needed to ensure good performance.

Experimental investigation of the effects of various parameters on viscosity reduction of heavy crude by oil-water emulsion

The effects of water content, shear rate, temperature, and solid particle concentration on viscosity reduction （VR） caused by forming stable emulsions were investigated using Omani heavy crude oil. The viscosity of the crude oil was initially measured with respect to shear rates at different temperatures from 20 to 70℃. The crude oil exhibited a shear thinning behavior at all the temperatures. The strongest shear thinning was observed at 20℃. A non-ionic water soluble surfactant （Triton X-100） was used to form and stabilize crude oil emulsions. The emulsification process has significantly reduced the crude oil viscosity. The degree of VR was found to increase with an increase in water content and reach its maximum value at 50 % water content. The phase inversion from oil- oil emulsion occurred at 30 in-water emulsion to water-in- % water content. The results indicated that the VR was inversely proportional to temperature and concentration of silica nanoparticles. For water-in-oil emulsions, VR increased with shear rate and eventually reached a plateau at a shear rate of around 350 s^-1. This was attributed to the thinning behavior of the continuous phase. The VR of oil-in-water emulsions remained almost constant as the shear rate increased due to the Newtonian behavior of water, the continuous phase.

Synthesis and mechanism analysis of a new oil soluble viscosity reducer for flow improvement of Chenping heavy oil

Oil soluble viscosity reducers have gradually attracted the attention of petrochemical research due to their cleanliness and high efficiency.Considering the high viscosity and non-Newtonian fluid properties of Chenping heavy oil found in China,a series of new oil soluble viscosity reducers with different proportions and molecular weights were prepared by free radical polymerization using octadecyl acrylate,2-allylphenol and N-methylolacrylamide as monomers.The viscosity reducer was applied to different types of heavy oil and found that it exhibited a better effect on heavy oils with high asphaltene content.The test of rheological behavior of heavy oil with additive was performed at wide range of shear rate(3–90 s^(-1))and temperature range(30–100°C).The apparent viscosity reduction rate was up to 70.09%,which was better than the industrially relevant ethylene–vinyl acetate copolymer under the same test condition.In addition,the effect of viscosity reducers on the components of heavy oil and the energy change of the system simulated by molecular dynamics simultaneously was investigated.The consistency of the simulated and experimental results show that the effect of viscosity reduction closely related to the crystallization process of wax and the viscosity reducer can reconstruct the surface structure of asphaltene and diminish the connection of benzene ring.

Synthesis of silica/metatitanic acid nanocomposite and evaluation of its catalytic performance for aquathermolysis reaction of extra-heavy crude oil

A lipophilic silica/metatitantic acid（denoted as Si O2/H2 TiO 3） nanocomposite was synthesized by hydrothermal reaction with surface-modified Si O2 as the lipophilic carrier. As-synthesized Si O2/H2 TiO 3nanocomposite was used as a catalyst to promote the aquathermolysis reaction of extra-heavy crude oil thereby facilitating the recovering from the deep reservoirs at lowered temperature. The catalytic performance of the as-synthesized Si O2/H2 TiO 3catalyst for the aquathermolysis reaction of the heavy oil at a moderate temperature of 150 °C was evaluated in relation to the structural characterizations by TEM,FTIR,XRD and FESEM as well as the determination of the specific surface area by N2adsorption–desorption method. Findings indicate that as-synthesized Si O2/H2 TiO 3nanocomposite exhibits an average size of about 20 nm as well as good lipophilicity and dispersibility in various organic solvents; and it shows good catalytic performance for the aquathermolysis reaction of the extra-heavy oil extracted from Shengli Oilfield of China. Namely,the assynthesized Si O2/H2 TiO 3catalyst is capable of significantly reducing the viscosity of the tested heavy oil from58,000 c P to 16,000 c P（referring to a viscosity reduction rate of 72.41%） at a mass fraction of 0.5%,a reaction temperature of 150 °C and a reaction time of 36 h,showing potential application in downhole upgrading heavy crude oils.

Effects of Reservoir Minerals and Chemical Agents on Aquathermolysis of Heavy Oil during Steam Injection

以便有效地在蒸气注射期间减少重油的粘性，一个催化剂系统，由水库矿物质，镍硫酸盐，和蚁的酸组成，被用来在从显示的 Liaohe oilfield.Experimental 结果提取的重原油的 aquathermolysis 上施加催化效果在实验使用的所有水库矿物质在 aquathermolysis 和油粘性减小率上有催化效果，这在 aquathermolysis reaction.If 镍硫酸盐 w 以后从24%～36%

Numerical Study on Viscosity Reduction in Mining Heavy Oil by Circulating Hot Water

Viscosity reduction is an important process in mining heavy oil.To predict the temperature variation and viscosity variation of heavy oil in flow direction,computational fluid dynamics(CFD) was adopted to simulate the process of heat transfer and flow in this paper.Moreover,an objective function,namely viscosity reduction efficiency,was established to analyze the effect of viscosity reduction.The results indicate that circulating hot water can reduce viscosity significantly,and that the effect of viscosity reduction depends on the inlet temperature and inlet volumetric flow rate of hot water.There is a maximum temperature of heavy oil in flow direction.With the inlet volumetric flow rate of 2.0m3/h and the inlet temperatures of 60,℃,70,℃ and 80,℃,viscosity reduction efficiencies are 94.6%,96.7% and 97.3%,respectively.With the inlet temperature of 70,℃ and the volumetric flow rates of 1.5m3 /h,2.0 m3/h and 2.5m3/h,viscosity reduction efficiencies are 94.4%,96.7% and 97.2%,respectively.

Aquathermolysis of conventional heavy oil with superheated steam

This paper presents a new aquathermolysis study of conventional heavy oil in superheated steam. A new high temperature autoclave was designed, where volume and pressure could be adjusted. Aquathermolysis was studied on two different conventional heavy oil samples under different reaction times and temperatures. Experimental results show that aquathermolysis does take place for conventional heavy oil. As reaction time increases, the oil viscosity reduces. However, the reaction will reach equilibrium after a certain period of time and won＇t be sensitive to any further reaction time any more. Analysis shows that, while resin and asphaltenes decrease, saturated hydrocarbons and the H/C ratio increase after reaction. The main mechanism of aquathermolysis includes hydrogenization, desulfuration reaction of resin and asphaltenes, etc.

Aquathermolysis of heavy crude oil with ferric oleate catalyst

Oil-soluble catalysts could be of special significance for reducing the viscosity of heavy crude oil, because of their good dispersion in crude oil and high catalytic efficiency toward aquathermolysis. Ferric oleate was synthesized and applied as catalyst in the aquathermolysis reaction of Shengli heavy oil. It was found that ferric oleate was more efficient for heavy oil cracking than Co and Ni oleates. Besides, it was superior to oleic acid and inorganic ferric nitrate and achieved the highest viscosity reduction rate of up to 86.1%. In addition, the changes in the components of Shengli heavy oil before and after aquathermolysis were investigated by elemental analysis, Fourier transform infrared spectrometry, and ^1H nuclear magnetic resonance spectroscopy. Results indicated that ferric oleate contributed to a significant increase in the content of light components and decrease in the content of resin, N and S. The as-prepared ferric oleate showed good activity for reducing the viscosity and improving the quality of the heavy crude oil, showing promising application potential in aquathermolysis of heavy crude oil.

In situ preparation of well-dispersed CuO nanocatalysts in heavy oil for catalytic aquathermolysis

We developed an in situ synthesis strategy for preparing well-dispersed CuO nanoparticles as aquathermolysis catalyst for viscosity reduction in Shengli heavy oil(China). A Cu(OH)_2-contained microemulsion was employed as a carrier to disperse the precursor Cu(OH)_2 to the heavy oil phase. Under aquathermolysis condition(240 ℃, 2.5 MPa of N_2), the Cu(OH)_2 precursors would first be converted in situ to well-crystallized and size-homogeneous CuO nanoparticles naturally, catalyzed by which the viscosity of Shengli heavy oil could be reduced as much as 94.6%; simultaneously, 22.4% of asphaltenes were converted to light components. The agglomeration of the in situ prepared monoclinic CuO nanoparticles could be negligible throughout the catalytic reaction. Based on the characterization results of ~1 H NMR, elemental analysis and GC-MS of oil samples before and after catalytic aquathermolysis, the mechanism for viscosity reduction of heavy oil in the catalytic system was investigated.

Heating of heavy oil by circulating hot water in closed double casing in ultra-deep wells

In heavy oil production,the loss of energy to ambient surroundings decreases the temperature of the heavy oil flowing upwards in a vertical wellbore,which increases the oil viscosity and the oil may not flow normally in the wellbore.Therefore,it is necessary to lower the heavy oil viscosity by heating methods to allow it to be lifted easily.Heating of heavy oil in an oil well is achieved by circulating hot water in annuli in the well（tubing-casing annulus,casing-casing annulus）.In this paper,based on heat transfer principles and fluid flow theory,a model is developed for produced fluids and hot water flowing in a vertical wellbore.The temperature and pressure of produced fluids and hot water in the wellbore are calculated and the effect of hot water on heavy oil temperature is analyzed.Calculated results show that the hot water circulating in the annuli may effectively heat the heavy oil in the tubing,so as to significantly reduce both oil viscosity and resistance to oil flow.

Experimental study of Iranian heavy crude oil viscosity reduction by diluting with heptane, methanol, toluene, gas condensate and naphtha

Due to the high viscosity of heavy crude oils,production from these reservoirs is a demanding task.To tackle this problem,reducing oil viscosity is a promising approach.There are various methods to reduce viscosity of heavy oil:heating,diluting,emulsification,and core annular flow.In this study,dilution approach was employed,using industrial solvents and gas condensate.The viscosity of two Iranian heavy crude oils was measured by mixing with solvents at different temperatures.Dilution of both oil samples with toluene and heptane,resulted in viscosity reduction.However,their effect became less significant at higher concentrations of diluent.Because of forming hydrogen bonds,adding methanol to heavy crude oil resulted in higher viscosity.By adding condensate,viscosity of each sample reduced.Gas condensate had a greater impact on heavier oil;however,at higher temperatures its effect was reduced.Diluting with naphtha decreased heavy oil viscosity in the same way as n-heptane and toluene.Besides experimental investigation,different viscosity models were evaluated for prediction of heavy oil/solvent viscosity.It was recognized that Lederer'model is the best one.

稠油乳化黏度测量曲线与乳液特性的关系

稠油化学驱过程中降黏剂浓度对稠油乳化影响明显,通过测量不同浓度降黏剂的稠油乳状液黏度-时间曲线,以黏度、降黏率为指标分析了黏度曲线与乳液特性的关系。结果表明,当降黏剂的浓度远大于临界乳化浓度时,形成稳定O/W乳状液,黏度低、降黏率大于95%。当降黏剂的浓度大于临界乳化浓度时,形成O/W乳状液,而后随着表面活性剂向油相的迁移,油滴聚并、分层。当降黏剂的浓度与临界乳化浓度相当时,乳状液油O/W转化为W/O,黏度大幅度提高。当降黏剂的浓度小于临界乳化浓度时,只能形成W/O乳状液。

表面活性剂对水驱普通稠油油藏的乳化驱油机理

为了研究乳化降黏驱油剂对不同渗透率的水驱普通稠油油藏的驱油效率和孔隙尺度增效机理,选取了烷基酚聚氧乙烯醚(J1)、α-烯基磺酸盐类表面活性剂(J2)、十二烷基羟磺基甜菜碱(J3)、J3与烷基酚聚氧乙烯醚羧酸盐复配表面活性剂(J4)作为驱油剂,开展了4种驱油剂一维驱油和微观驱油模拟实验,明确了乳化降黏驱油剂在孔隙尺度的致效机理。结果表明,降低界面张力对提高驱油效率的作用大于提高乳化降黏率。在油藏条件下,乳化降黏驱油剂需要依靠乳化降黏和降低界面张力的协同增效作用,才能大幅提高驱油效率。乳化降黏驱油剂的乳化能力越强、油水界面张力越低,驱油效率增幅越大。当化学剂乳化降黏率达到95%时,油水界面张力从10^(-1)mN/m每降低1个数量级,化学剂在高渗透和低渗透岩心中的驱油效率依次提高约10.0%和7.8%。乳化降黏驱油剂注入初期通过降低界面张力,使得高渗透岩心和低渗透岩心中的驱替压力分别为水驱注入压力的1/2和1/3,从而提高注入能力。注入后期大块的原油被乳化形成大量不同尺寸的油滴,增强原油流动性,提高驱油效率。乳化形成的界面相对稳定的稠油油滴,能暂堵岩石的喉道和大块稠油与岩石颗粒形成的通道。油滴的暂堵叠加效应,使高渗透和低渗透岩心的驱替压差分别为水驱压差的5.2倍和32.3倍,大幅提高了注入压力,从而扩大平面波及面积。降黏驱油剂驱油实现了提高驱油效率的同时扩大波及范围。研究结果为水驱稠油开发用驱油剂的研发提供参考,为大幅提高水驱普通稠油采收率奠定基础。

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。

扶余油田外围区块生物胶降黏压裂技术试验

扶余油田外围区块原油密度大、黏度高、凝固点高、含蜡量高,采用常规胍胶携砂压裂技术无法有效开采,压裂投产后初期产量较低,达不到效益产能,外围区块基本处于未开发动用状态。为此,研发了生物胶降黏剂体系与压裂工程技术相配套的降黏压裂技术,并进行了实验评价。评价结果显示,该生物胶具有降凝、降黏、防蜡、乳化、驱油等性能,可显著提高原油流动性。现场试验分为生物胶降黏加砂压裂和生物胶降黏不加砂压裂两种技术方式,共在扶余外围及稠油区块累计实施45口井。前置液胍胶造主裂缝+支撑剂+生物胶降黏剂+支撑剂+后置液降黏剂的技术方法应用在新投产的外围及稠油区块,对比老区内部,在储层物性变差的条件下,投产后产油量超设计产能1.6倍,是老区内部的1.4倍。生物胶降黏不加砂压裂技术主要应用在老井二次压裂或多轮次压裂稠油区块或黏度上升井层,同等条件下对比,黏度由压裂前的70mPa·s下降到25mPa·s,增产量是同区块常规压裂的1.3倍。

“双碳”背景下医疗废弃物用于原油流动性改进剂综合性实验设计

为了进一步提高应用化学专业本-硕学段学生的创新思维和综合实验技能,根据新工科建设要求,渗透“医疗废弃物回收与资源化利用”助力“双碳”目标实现这一理念,以废弃口罩为研究对象,设计了系列聚丙烯基原油流动性改进剂综合性实验,评价其降黏效果。该实验将化学基础理论知识用于油田应用化学领域,将实验技能与现场作业相结合,提升学生的专业技能和油田现场适应能力;帮助学生深入了解降黏剂降黏机理,掌握其在不同环境的降黏剂评价方法和数据处理能力,进而提高创造性解决问题的能力。

稠油化学降黏剂研究进展与发展趋势

在双碳背景下,以热采为主的稠油开采技术如何经济、高效、绿色地提高稠油采收率是研究者关注的重点问题。实现稠油油藏的商业开采,其本质是降低稠油黏度,提高流动能力。文章系统分析了稠油的致黏机理以及各类降黏剂的降黏机理,总结了乳化降黏剂、油溶性降黏剂、纳米降黏剂的合成工艺,评价了不同降黏剂的优势与不足。并对降黏剂发展趋势进行讨论与展望。对现有化学降黏剂的梳理有助于新型降黏剂体系的开发,提高稠油油藏开采效率。

CO_(2)响应型β-环糊精材料用于稠油降黏

制备了一种环境友好型马来酸酐改性β-环糊精(MAH-β-CD),温和条件下将其与聚醚胺(JD230)通过静电作用合成了具有CO_(2)响应性的表面活性剂(MJD230)。MJD230能与稠油形成稳定的水包油乳液,进而有效降低溶液的表面张力。在CO_(2)调控下,MJD230可重复用于稠油的乳化降黏和破乳。利用FTIR对MJD230结构进行了表征。通过观察降黏率和乳液粒径优化MJD230的合成条件,同时对降黏效果和乳液的稳定性进行了考察。将在反应温度为60℃,反应时间为60min,MAH-β-CD与JD230物质的量比为2∶1条件下制备的MJD230配成质量分数为0.5%的MJD230水溶液,其与稠油按照体积比为3∶7乳化后,稠油降黏率可达99.19%。反应体系pH和电导率的可逆变化证明了MJD230溶液对CO_(2)的响应性,这为表面活性剂驱油和CO_(2)捕集相结合提高稠油采收率提供了可行的途径。