Viscosity Reduction of Heavy and Extra Heavy Crude Oils by Pulsed Electric Field

Abstract

The ever-increasing world energy demand would require the use of all hydrocarbon resources available, especially heavy and extra-heavy crude oils in the near future. However, transportation of these crudes is very difficult due to their high viscosity and low mobility. There are many different methods to reduce heavy crude oil viscosity. Some of these methods are heating, blending, water-in-oil emulsion formation, upgrading, and core annular flow. But each of these methods has several problems. The aim of this research is to investigate a new method to reduce viscosity for pipeline transportation. In this method asphalt molecules, which are mainly responsible for high viscosity, are aggregated temporarily to micronized clusters while going through a pulsed electric field, causing a reduction of the viscosity. This method does not change the oil's temperature and is very suitable for underwater pipelines. The authors applied electric fields in the range of 0.5 to 1.8 KV/mm an Iranian heavy crude oil and viscosity reduction up to 7% was observed.     

用磺化稠油降低稠油粘度的初步研究

在低温下 (15～ 2 0℃ )用 5 0 %～ 6 0 %的硫酸将辽河稠油磺化 ,得到了一系列磺化稠油 ,在 5 0℃粘度为 115 3mPa·s的辽河稠油中按质量比 2 g/kg加入磺化稠油 ,使 5 0℃粘度降至 786～ 914mPa·s ,降粘率为 19.8%～31.8%。将磺化反应进行优化 ,得到磺化稠油的最好制备条件 :5 5 %硫酸 ,用量为稠油的 1.5 % ,在 15℃反应 2h。得到的磺化稠油在加剂量为 2 g/kg时使稠油 5 0℃粘度下降 30 .8%。稠油降粘率与加剂量的关系曲线很复杂 ,经过一个明显的极大值和一个极小值 ,极大值对应的加剂量为 2 g/kg ,即最佳加剂量。讨论了稠油降粘机理。图 1表 1参 2。     

The Viscosity of Crude Oils in 1,4-Dioxan

Viscosities of crude oil solutions from 0.1 to 1.0% (v/v) have been studied in 1,4-Dioxan as a solvent at temperature ranging from 293 to 313 K. Huggins, Kraemer, Martin, and Schulz-Blaschke relations were used by viscosity data to evaluate intrinsic viscosities and viscometric constant values. Degree of viscosity reduction (DVR) was also calculated. The size of the isolated molecule was evaluated in terms of intrinsic viscosity and shows that interactions between solute and solvent decrease with the rise in temperature.     

外磁场对原油粘度的影响

介绍处磁场原油性质影响的机理，提出了计算外磁场对原油粘度影响的模型，计算结果表明：外磁场对原油粘度的影响是各异性好的，当外磁场方向与原油流动方向垂直时，原油的粘度是下降，的且其降粘率随温度的升高而降低，在场强较小时，且温度高于原油凝固点的温区，理论与实验结果相答，当外磁场方向原油流动方向平行时，原油的粘度是增高的。     

4种委内瑞拉稠油乳化降黏特性实验研究

研究了含水量不同的4种委内瑞拉稠油的乳化降黏特性。所用乳化剂代号WS-4,为复配以其他活性物质的双金属催化聚醚,配成设定浓度的水溶液,加量按O/W乳状液计为250 mg/L。4种O/W稠油乳状液的流变特性不同,其中稠油2393（30℃黏度10.50 Pa.s,密度0.896 g/cm^3,含胶质沥青质35.6%）的乳状液（真实油水体积比60.1∶39.9,水相中WS-4表观浓度628 mg/L）流变性能最佳,在恒定剪切速率下（3.4-34 s^-1）表观黏度随温度升高（30-70℃）先略有增大,以后大幅度下降,随剪切时间延长（0-120 min）先略有增大,以后趋于下降,在恒定温度下（30-70℃）表观黏度随剪切速率增大（3.4-34 s^-1）持续下降,测试过程中乳状液不发生反相,最高表观黏度不超过530 mPa·s。稠油J-20的乳状液有相似的流变特性。在显微镜下观察到这两种稠油乳状液中,乳化剂水溶液完全铺展在油滴表面,原油充分分散,显示近似双连续相结构。从润湿热力学角度讨论了乳化降黏机理,还讨论了液滴尺寸与液滴聚并的关系。图16表2参12。     

A Viscosity Reduction Study on Chinese Extra Heavy Oil by the Addition of Synthesized Novel Oil-Soluble Viscosity-Reducing Agents

Abstract

A series of oil-soluble viscosity-reducing agents (VRAs), which includes two types of compounds, namely, copolymers and macromolecules, has been purposely synthesized and used as flow improvers (FIs) for Chinese extra heavy oil transportation treatment. In comparison with commercial FIs/pour point depressants (PPDs), the viscosity-reducing rates of the synthesized VRAs for extra heavy oil are significantly higher than those of commercial PPDs of T808A and ethylene-vinyl acetate copolymer (EVA) as FIs in higher temperature range (HTR), and their viscosity-reducing effects are similar to those of both EVA and T808A in the lower temperature range. The experimental results show good prospects in the development of highly efficient oil-soluble VRAs for extra heavy oil in HTR. It has provided a feasible basis for transporting dehydrated extra heavy oil by adding VRAs in HTR instead of by heating to a high temperature of 80°C, which can greatly reduce energy exhaustion. The effects of the related factors, such as type, composition, and carbon chain length of VRA molecules on their viscosity-reducing behaviors were also studied and are reported herein.     

超稠油乳化降粘剂SHVR-02的研制

用荧光法测得辽河油田杜84块杜54 30井超稠油(室温粘度54.8Pa·s)乳化剂的最佳HLB值为10.8。根据这一HLB值,由主剂脂肪醇聚氧乙烯醚、一种生物表面活性剂及辅剂快速渗透剂JFC配成了超稠油乳化降粘剂SHVR 02。当油水体积比为1.0∶0.7、水相中SHVR 02浓度为1g/L时,超稠油乳状液的粘度为492mPa·s,水相浓度增大至5g/L时乳状液粘度降至268mPa·s。在油水体积比1.0∶0.7、水相SHVR 02浓度3g/L、混合温度50℃条件下,粘度在6.2～20.9Pa·s的8种辽河稠油形成的乳状液,粘度在53～148mPa·s之间。乳状液在40～80℃放置10h后,粘度随放置温度升高略有下降(378→248mPa·s),放置温度为90℃时乳状液发生反相,粘度升至26.1Pa·s。SHVR 02的乳化降粘效果优于3种对比乳化剂。SHVR 02形成的超稠油乳状液易破乳,与联合站现用破乳剂配伍。表6参14。     

稠油降粘剂HP在塔河S66井的应用

报道了乳化降粘剂HP用于塔河油田S6 6井稠油开采的现场试验结果并作了分析。HP的主剂为改性酚醚表面活性剂 ,复配以表面张力改进剂和抗盐聚合物 ,在 80℃下可抗耐矿化离子的浓度高达 2 .2 6× 10 5mg/L(包括Ca2 + +Mg2 + 4 .3× 10 3 mg/L)。S6 6井原油基本不含水 ,含气一般～ 10 % ,5 0℃粘度 9.2Pa·s。该井用掺稀油工艺生产 ,产液量由泵排量决定 ,为～ 6 6m3 /d。在为时 2 2d的现场试验中 ,用矿化度 5 .6× 10 4mg/L、含Ca2 + +Mg2 +4 .3× 10 3 mg/L的井水配制的浓度 4 75 0～ 6 0 0 0m/L的HP溶液从环空连续注入井内 ,油水体积比逐渐由 6 0∶4 0变为 70∶30 ,HP加量以总液量计由 2 2 0 0mg/kg逐渐降至 14 0 0mg/kg。HP加量在 2 2 0 0～ 16 0 0mg/kg范围时 ,产出的O/W乳状液 35～ 36℃下的粘度为 17.5～ 2 0 .0mPa·s ,而掺稀油时产出原油的粘度为 30 0mPa·s。当油水比由 6 0∶4 0变为 70∶30时 ,稠油、气、水的产出量分别由 35 .6t/d ,3.96m3 /d ,2 6 .4t/d变至 4 1.6t/d ,4 .6 2m3 /d ,19.8t/d。在采用掺稀油工艺时 ,稠油和气产出量分别为 2 9.7t/d和 3.30m3 /d ,回采稀油量为 33.0t/d。在现场试验中井口油压略升并大体维持稳定 ,对产生这一现象的原因作了分析。图 1表 3参 1。     

The Performance of Toluene and Naphtha as Viscosity and Drag Reducing Solvents for the Pipeline Transportation of Heavy Crude Oil

Heavy crude oil shows high viscosity combined with low mobility, which affects the efficient transportation through pipelines. Drag has long been identified as the main reason for the loss of energy in pipeline fluid transmission and other similar transportation channels. The main contributor to this drag is the viscosity as well as friction against pipe walls, which will result in more pumping power consumption. Various methods such as heating, upgrading, dilution, core annular flow, and emulsification in water have been used for their transportation. The influence of toluene and naphtha as a viscosity and drag reducing solvent on flow of Iraqi crude oil in pipelines was investigated in the present work. The effect of additive type, concentration, pipe diameter, solution flow rate, and heating on the percentage of drag reduction (%Dr) and percentage flow increase (%FI) were the variables of study. The maximum drag reduction was observed to be 40.48% and 34.32% using heavy oil flowing in pipeline diameter of 0.0508 m I.D. at 27°C containing 10 wt% naphtha and toluene, respectively. Also, the dimensional analysis is used for grouping the significant quantities into dimension less group to reduce the number of variables.     

吉林扶余油田稠油乳化降黏实验研究

针对典型油样进行组分分析,找出原油中影响黏度的主要因素。采用A型水溶性降黏剂进行乳化降黏实验,通过静态评价试验,研究了水溶性A型降黏剂与原油之间形成乳状液的稳定性和粒径分布、油水界面张力、降黏率及洗油率,考察了该降黏剂降黏效果。实验结果表明:原油中蜡含量迭14.7%,高含蜡是影响原油黏度的主要因素;降黏剂浓度越大,乳状液分水率越低,乳状液粒径分布越集中,油水界面张力越低,乳状液越稳定;油水比越大,分水率随降黏剂浓度变化越显著;随降黏剂浓度增大和油水比降低,降黏率逐渐升高,降黏率最高可达91.5%;该降黏剂有较好的洗油效果,洗油率为61.1%。     

胜坨油田稠油催化降粘技术研究

介绍了稠油催化降粘机理,对胜坨油田催化降粘可行性进行了分析研究,对稠油降粘催化剂以及催化剂助剂进行了筛选和研究,研制出适合胜坨油田稠油特点的催化剂和催化剂助剂,降粘效率达到60％以上,制定了催化降粘的选井条件及现场施工注入工艺,为胜坨油田稠油蒸汽吞吐采收率的提高提供了新的工艺技术。     

稠油的类乳化复合降粘作用机理

讨论了油水乳状液的粘度与水外相体积分数之间关系的 3种理论公式 (Einstein ,Hatschek ,Richardson公式 )和真实乳状液的各种复杂类型 ,包括极少量水与油形成的核心 环状流。提出在稠油中加入少量的水、油溶性降粘剂、乳化剂 ,使稠油形成油相不易聚结的水外相类乳状液 ,以大大降低稠油粘度的方法并讨论了涉及的机理。将5 0℃、6 3.5s- 1 下粘度 >17.8Pa·s的胜利乐安稠油与加有 0 .1%特制乳化剂、0 .0 5 %油溶性共聚物降粘剂MSA的水在 5 0℃混合 ,油水体积比分别为 8.5∶1.5和 8.0∶2 .0 ,药剂加量以药剂与稠油的质量比表示 ,形成的类乳状液的粘度分别为 6 73.2和 2 4 1.5mPa·s (5 0℃ ,113.5s- 1 ) ,降粘率分别为 96 .6 %和 98.8%。在油水体积比 8.5∶1.5 ,MSA加量 0 .0 5 % ,乳化剂加量 0 .1% ,温度 5 0～ 80℃的条件下 ,用煤油代替水 ,在 <80℃时稠油降粘率均较小 ,且温度越低 ,降粘率差别越大。考察了MSA加量 (0 .0 1%～ 0 .1% )、乳化剂加量 (0 .0 5 %～ 0 .1% )、油水体积比 (8.5∶1.5～ 7.0∶3.0 )、乳化温度 (5 0～ 70℃ )的影响。本方法可用于稠油的井筒降粘开采。图 2表 4参 13。     

甜菜碱溶液的界面性能及其在稠油降粘中的应用

为探索稠油乳化降黏过程中乳化剂的构效关系,考察了直链烷基甜菜碱(ASB)、二甲苯基取代甜菜碱(BSB)与稠油的油/水动态界面张力和界面扩张流变参数,测定了甜菜碱溶液与稠油形成的乳状液的稳定性、粒径和黏度。结果表明：甜菜碱分子的亲水基团平铺在界面上,形成具有一定弹性和强度的油/水界面膜,易与稠油形成稳定的O/W乳状液,显著降低了油相黏度。当油/水体积比为1∶1时,2种甜菜碱在质量分数为0.1%～1.0%的范围内,降黏率大于98%。ASB分子与稠油中活性物质混合吸附、协同作用,具有比BSB更高的界面活性和更强的稳定稠油乳状液能力,能在更宽的油/水体积比范围内有效降黏。     

孤岛稠油乳化降粘剂FH-02应用性能研究

FH-02是加有抗钙镁离子剂的非离子、阴离子表面活性剂混合物。报道了该剂对孤岛稠油的乳化降粘性能。FH-02溶液用孤岛油田回注污水配制,实验温度50℃,根据静置时脱水率和SV值确定乳状液稳定性。孤岛稠油与0.5%FH-02溶液按体积比80/20、70/30、60/40混合时形成稳定性递减的O/W型乳状液,体积比50/50时形成很不稳定的W/O型乳状液,最佳油水体积比为70/30。在该体积比下,0.5%~1.5%的FH-02溶液与孤岛稠油形成稳定性相近的O/W乳状液,FH-02水溶液的最佳质量分数为0.54%;FH-02质量分数由0.1%增至0.5%时,与粘度21230 mPa.s的稠油形成的乳状液粘度由5485 mPa.s降至303 mPa.s,乳化降粘率由74.16%增至98.57%。0.5%的FH-02水溶液与粘度3546~21230 mPa.s的6种稠油形成的乳状液,粘度在82~303 mPa.s范围,乳化降粘率≥97.7%。对于粘度12871 mPa.s的稠油,FH-02的乳化降粘率(98.8%)高于孤岛油现用3种乳化降粘剂(95.7%~96.6%)。FH-02不影响现用4种原油破乳剂的效能。表6参7。     

胜坨油田稠油催化降粘技术研究

介绍了稠油催化降粘机理,对胜坨油田催化降粘可行性进行了分析研究,对稠油降粘催化剂以及催化剂助剂进行了筛选和研究,研制出适合胜坨油田稠油特点的催化剂和催化剂助剂,降粘效率达到60％以上,制定了催化降粘的选井条件及现场施工注入工艺,为胜坨油田稠油蒸汽吞吐采收率的提高提供了新的工艺技术。     

稠油磺酸盐及其对稠油的乳化降粘性能研究

乳化降粘开采稠油是一项提高稠油采收率的新技术,开发廉价高效的乳化降粘剂是该技术的关键。以大庆黑帝庙稠油为原料,发烟硫酸为磺化剂,合成了稠油磺酸盐。考察了酸烃比、反应温度、反应时间对磺化反应的影响。确定了磺化反应的最佳工艺条件为：酸烃比1．6：1,反应温度为50℃-55℃,反应时间为2h。测试了其对稠油的乳化降粘性能,结果表明,35℃时,稠油磺酸盐对稠油具有较好的乳化降粘效果,降粘率达90％以上。复配后效果更佳,且具有较好的适用性。     

绥中36-1油田稠油降粘剂HOT-RE室内研究

稠油乳化剂HOT RE是一种含有耐盐基团的表面活性剂。在HOT RE室内性能评价中所用的油样为取自绥中 36 1油田的脱气脱水稠油 ,在 4 0℃下粘度为 5 6 .2Pa·s。实验研究结果如下。在含水量由 2 4 %增至 2 8%时稠油乳状液由油包水型转变为水包油型。加入 0 .0 5 %～ 0 .3%NaOH可使油水体积比 70 30的O W型稠油乳状液 4 0℃时的粘度降至数百mPa·s,但水相矿化度为 3.5× 10 4 mg L时则无降粘作用。质量比 1∶1的NaOH +HOT RE在加量为 0 .0 5 %～ 0 .5 %时乳化降粘效果更好 ,但当水相矿化度为 3.5× 10 4 mg L时其有效加量范围减至 0 .4 %～ 0 .6 %。加入 0 .2 %～ 0 .4 %HOT RE的 70 30的O W型稠油乳状液 4 0℃时的粘度为 6 0 0～ 2 70mPa·s,温度 5 0～ 70℃时粘度有所下降 ,水相矿化度≤ 7.0× 10 4 mg L时 4 0℃粘度大体不变。加入HOT RE形成的O W型稠油乳状液用选择适当的破乳剂不难破乳 ,脱水率可高达～ 90 %。在储层岩心流动实验中 ,与海水相比HOT RE水溶液的注入压力较低 ,从油饱和岩心中驱出的油量较多。图 5表 2参 8     

单家寺稠油降粘剂SJ及其O/W型乳状液流变性研究

报道了乳化降粘剂SJ对单家寺稠油的乳化降粘作用。SJ为含少量无机碱和盐的石油磺酸盐、非离子表面活性剂的混合物 ,在 30 0℃、3.4 5MPa下热处理 2 4h后使用。实验油样为单家寺一口井所产超稠油 ,含胶质 31.9% ,含沥青质 9.1% ,酸值 1.83mgKOH/g油 ,5 0℃、1.2s-1粘度 6 3.4Pa·s。水样为该油田采出水 ,矿化度 19.5 g/L。在大范围内变化SJ加量和油水体积比 ,求得乳化剂在水中的最佳加量为 0 .3%～ 0 .5 % ,最佳油水比为 80∶2 0～70∶30 ,所得O/W型稠油乳状液 5 0℃、1.2s-1下的粘度为 4 2 0～ 180mPa·s,在 5 0℃放置 90min后脱水率 >92 %。SJ的乳化降粘性能和形成的乳状液稳定性均符合稠油生产要求。在 6 0℃、剪切速率 5 0～ 12 0 0s-1范围考察了SJ用量 0 .3%、油水比 80∶2 0～ 2 0∶80的 5个O/W乳状液的粘度 剪切速率关系 ,发现乳状液的粘度均随剪切速率增大而减小 ,在剪切速率 >10 0 0s-1后不再变化 ,但假塑性随油水比减小而减小。在 30～ 70℃范围乳状液流变性变化规律相似。图 1表 2参 3     

稠油降黏开采技术研究进展

综述了稠油降黏开采技术的近期进展，重点是乳化降黏法和微生物法中生物表面活性剂的作用，论题如下。前言：国外、国内稠油油藏及其开采。①稠油组成及其高黏实质。②物理法降黏，包括掺稀油法和蒸汽、电加热法，新疆塔河油田一口井用掺稀油法试油开采。③化学法降黏，包括催化水热裂解、乳化、破乳及油溶性降黏剂，简述了降黏机理．介绍了国内乳化降黏剂研制和应用方面的成果。④微生物法降黏：包括微生物采油机理、生物表面活性剂性质、生物表面活 性剂用于EOR、国内产表面活性剂菌种筛选。参44。     

Demulsification of Extra Heavy Crude Oil

Abstract

The demulsification of orimulsion, an extra heavy crude oil, was studied by a PDY-1 instrument of electric demulsification. Some commercial demulsifiers, including P, RN, and RB series demulsifiers, were tested; however, their dewatering efficiency was unsatisfactory. ZQ series demulsifiers were synthesized and applied. It is pointed out that the ZQX3 series demulsifier had satisfactory dewatering ability for extra heavy crude oil emulsion. In order to improve the dewatering efficiency, toluene diisocyanate (TDI) was used as a chain extender to modify the ZQ series demulsifiers and an assistant—ammonium sulfate (t1)—was added. The results indicate that the dewatering efficiency of ZQ43 and a t1 mixture reaches excellent dewatering efficiency.