Catalytic Performance of Aquathermolysis and Viscosity Reduction of Heavy Oil over a WO_(3)/ZrO_(2) Solid Acid

Tungstated zirconia(WO_(3)/ZrO_(2))solid acid catalysts with different WO_(3) contents were prepared by a hydrothermal method and then used in the catalytic aquathermolysis of heavy oil from Xinjiang.The WO_(3)/ZrO_(2) solid acid catalyst was characterized by a range of characterization methods,including X-ray diffraction,NH3-temperature programmed desorption,and pyridine infrared spectroscopy.The WO_(3) content of the WO_(3)/ZrO_(2) catalysts had an important impact on the structure and property of the catalysts.When the WO_(3) mass fraction was 20%,it facilitated the formation of tetragonal zirconia,thereby enhancing the creation of robust acidic sites.Acidity is considered to have a strong impact on the catalytic performance of the aquathermolysis of heavy oil.When the catalyst containing 20%WO_(3) was used to catalyze the aquathermolysis of heavy oil under conditions of 14.5 MPa,340℃,and 24 h,the viscosity of heavy oil decreased from 47266 to 5398 mPa·s and the viscosity reduction rate reached 88.6%.The physicochemical properties of heavy oil before and after the aquathermolysis were analyzed using a saturates,aromatics,resins,and asphaltenes analysis,gas chromatography,elemental analysis,densimeter etc.After the aquathermolysis,the saturate and aromatic contents significantly increased from 43.3%to 48.35%and 19.47%to 21.88%,respectively,with large reductions in the content of resin and asphaltene from 28.22%to 25.06%and 5.36%to 2.03%,respectively.The sulfur and nitrogen contents,and the density of the oil were significantly decreased.These factors were likely the main reasons for promoting the viscosity reduction of heavy oil during the aquathermolysis over the WO_(3)/ZrO_(2) solid acid catalysts.

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.

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.

Rheological properties and viscosity reduction of South China Sea crude oil

The rheological properties of South China Sea （SCS） crude oil were studied. A group of synthetic long-chain polymers, including octadecyl acrylate-maleic anhydride bidodecyl amide copolymer （VR-D）, octadecyl acrylate-maleic anhydride bioctadecyl amide copolymer （VR-O） and octadecyl acrylate-maleic anhydride phenly amide copolymer （VR-A）, were employed to serve as viscosity reducers （VRs）. Their performance was evaluated by both experimental and computational methodologies. The results suggest that the SCS crude oil has low wax content yet high resin and asphaltene contents, which lead to high viscosity through formation of association structures. Additionally, the SCS crude oil appears to be a pseudoplastic fluid showing linear shear stress-shear rate dependence at low temperature. Interestingly, it gradually evolves into a Newtonian fluid with exponential relationship between shear stress and shear rate at higher temperature. Synthetic VRs demonstrate desirable and effective performance on improvement of the rheological properties of SCS crude oil. Upon the introduction of 1000ppm VR-O, which is synthesized by using octadecylamine in the aminolysis reaction, the viscosity of SCS crude oil is decreased by 44.2% at 15 ℃ and 40.2% at 40℃. The computational study suggests significant energy level increase and shear stress decrease for VR-containing crude oil systems.

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.

Drag reduction by linear viscosity model in turbulent channel flow of polymer solution

A further numerical study of the theory that the drag reduction in the turbulence is related to the viscosity profile growing linearly with the distance from the wall was performed.The constant viscosity in the Navier-Stokes equations was replaced using this viscosity model.Some drag reduction characteristics were shown comparing with Virk's phenomenology.The mean velocity and Reynolds stress profiles are consistent with the experimental and direct numerical simulation results.A drag reduction level of 45% was obtained.It is reasonable for this linear viscosity model to explain the mechanism of turbulence drag reduction in some aspects.

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.

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.

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.

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%).

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.

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.

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.

Mechanism of sulfide effect on viscosity of HPAM polymer solution

The effect of sulfide on HPAM solution viscosity was studied using BROOKFIELD DV-II viscometer,and the interaction mechanism was discussed.The HPAM solution viscosity was investigated through fully reducing sulfide by the addition of hydrogen peroxide oxidation,and the mechanism of increasing polymer viscosity was investigated.The experimental results also show that there is a critical concentration of 15 mg/L.Below it,the loss rate of HPAM solution viscosity increases more rapidly,but becomes slowly above the critical concentration.A theoretical guidance for oilfields to prepare polymer solution using sewage-water by eliminating sulfide,and it is also importance to prepare polymer solution using sewage-water and save fresh water.

The Effects of Dispersed Phase Morphology Induced by Flow on the Bulk Viscosity of HDPE/PA Blends

The apparent shear viscosity （ηα） of a blend composed of 97 wt % high-density polyethylene （HDPE） and 3 wt % polyamide （PA-66） was measured by capillary rheometry at different shear rates, below, near and above the melting point of PA-66, i.e. 240℃, 260℃ and 280℃, respectively. At 260℃ and a high shear rate, ηα of the blend reduced abnormally; and at 260℃, was lower than that at 280℃. The images of etched surface of extrudate observed by the SEM showed different dispersed phase morphology, induced by flow at different temperatures. It is suggested that the formation of fibrillar morphology of dispersed phase is a key factor for the abnormal reduction of ηα for the HDPE/PA blend.

A Model for FeSiMg Alloy Production by Reduction Technique

Ferrosilicon magnesium is basic foundry alloys used for the production of ductile cast iron. Magnesium content plays an important role in the produced alloy grades from dolomite ore. The focus of the present work is to simulate mathematical model to predict magnesium content in the ferrosilicon magnesium, which produced by silicothermic reduction of calcined dolomite. The basic assumptions of this model are: constant low viscosity of molten charge, the reaction is irreversible of second order and the reaction is isothermal. The reaction is based on the following equation: 2MgO+2Si →Mg2Si+SiO2 The results of previous work was found to be in a good coincidence with the predicted values by the model [Mg]=(MgO0)[Si0][eKt[(MgO0)-[Si0]]-1]/ (MgO0)[eKt[(MgO0)-[Si0]]-[Si0]] where [Mg] is the concentration of magnesium metal in ferrosilicon magnesium alloy in mol/L. [Si0] and (MgO0) are the initial concentration of silicon and magnesium oxide in charge in mol/L, while t is time in second, K is the reaction rate constant ( 3.26588x10-7 L Sec-1 mol-1). The predicted values are greater than the experimental values;this may be attributed to the use of concentration instead of the activity. The predicted values of magnesium content in ferrosilicon magnesium alloy are in a good agreement with the experimental results obtained in previous work at low viscosity.

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。

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。

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。

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。