微生物单井处理技术及其现场应用效果分析

通过分析含蜡原油和常规稠油的不同族组分的特点,有针对性地筛选出具防蜡作用的细菌F18 菌组和具降黏作用的F16菌组,并通过其与原油作用实验探索细菌防蜡和降黏的机理。研究表明,F18 菌组对长链脂肪烃的降解能力强,产表面活性剂能力强,经F18菌组作用后,原油中对结蜡贡献较大的烷烃组分减少,使原油含蜡量和凝固点下降;F16 菌组能降低原油黏度,对黏度50~3000 mPa·s(50℃)的原油的降黏率在30%~85%,经F16 菌组作用后,原油的非烃组分减少,同时代谢产物中的生物表面活性剂能有效地改善常规稠油的流动性。已在696 口油井上实施了微生物单井处理,取得了显著的增油和油井维护效果。已累计增油72 843.5t,平均单井增油104.66t。其油井维护作用(特别是对含蜡油井)主要表现为延长热洗周期甚至代替热洗和减少化学药剂的用量。图7表1参11     

表面粘附菌膜及微生物清防蜡作用机理研究

研究了嗜蜡菌在钢铁表面的生长，证明了菌膜的存在，用细菌瓶法测定菌膜中的菌量与矿化度、菌液浓度及作用时间的关系，同时观察到嗜蜡菌对含蜡原油清防蜡及乳化作用的效果。结果表明，嗜蜡菌在钢铁表面形成的菌膜有显著的防蜡作用，可改变金属表面的润湿性，阻止蜡沉积，嗜蜡菌产生的生物表面活性剂能明显分散原油。盐度低于15％时菌量较多，高于15％后菌量明显减少，且随着菌液浓度增加而增加，接种量到15％时趋于稳定。     

复配型石蜡基原油乳化降黏剂的研制和评价

针对大庆油田高含蜡原油开采和集输中采用的传统加热方式存在能耗大、成本高、占用设备及人力多、停输有凝管堵塞危险等问题,利用FZ区块原油样品,进行乳化剂ZX-1的制备及性能研究。结果表明:乳化剂ZX-1最佳配方是AE1910∶SDBS配比为1∶2,在温度40℃条件下,降黏率可达78%;乳化剂ZX-1具有优良的乳化降黏和防蜡性能,有助于原油脱水。其降黏和防蜡机理为:加入乳化剂后,含水原油形成O/W型乳状液,乳化剂分子在油滴表面和油管壁面做定向排列,水分子围绕活性剂的单分子层形成极性水膜,从而既防止了蜡在管壁表面的黏附,又防止了油滴的聚集。     

萨北过渡带本原微生物采油菌种的评价研究

为有效开发萨北过渡带地区低产低效及稠油井，进行了本原微生物采油菌种的培养、筛选、分离和提纯，获得了本原微生物降粘菌种并对其性能进行了评价。筛选菌种经乳化、降粘实验等综合评价，对萨北过渡带原油有一定的效果，能利用原油组分产气、有机酸和生物表面活性剂等代谢产物。测试结果表明，配伍菌的效果好于单菌株，特别是对原油粘度大于80mPa·s、含蜡大于20％、含胶高于30％的油样效果突出，降蜡率平均为20．2％；降胶率在15％～25％。筛选菌种对提高原油采收率具有明显的作用。     

Pseudomonas aeruginosa菌的原油除蜡降黏性能

采用单细胞Raman-D2O同位素标记技术确定了5种原油嗜蜡菌中的优势菌种;考察了其最佳生长条件,并对其代谢产物及其对原油的除蜡降黏性能进行测定.结果表明:优势原油嗜蜡菌种为SS1,属于铜绿假单胞菌属(Pseudomonas aeruginosa);其最佳生长条件为温度36℃、pH值7、NaCl质量浓度5 g/L;该菌...     

产表面活性剂菌与稠油降解菌复配对原油黏度的影响

稠油微生物降解是微生物采油的重要机理之一,但其效率较低,不能明显改变稠油化学组成,降低稠油黏度,从而影响采油效率。针对这一问题,将产表面活性菌与稠油降解菌复配,通过测定菌种作用前后原油的黏度确定产表面活性菌与稠油降解菌的最佳复配比例;通过原油四组分分析和变性梯度凝胶电泳,研究了生物表面活性剂对稠油生物降解的强化作用。结果表明,产表面活性菌T-1、X-3与稠油降解菌QB26、QB36适宜的复配体积比为2∶2∶1∶1。菌种复配作用后,稠油黏度明显降低,与单独使用降解菌相比降黏率平均提高33.1%,胶质与沥青质平均降解率提高8.0%和4.9%。产表面活性剂菌的加入增加了表面活性剂含量,降低了胶质沥青质等相对重质组分的含量;产表面活性剂菌通过产生表面活性剂,使原油降黏增溶,形成小液滴,易于被稠油降解菌捕获降解,不仅降低稠油黏度,还提高了稠油降解菌的数量。生物表面活性剂对稠油生物降解具有明显的强化作用,在微生物采油技术中具有良好的应用潜力。图1表1参19     

高温产乳化剂菌原位生长下的微观驱油机理

以高温产乳化剂菌嗜热脂肪地芽孢杆菌SL-1为对象,研究该菌株的生长和界面趋向性,同时利用微观仿真可视模型,研究SL-1菌对水驱后残余油的驱替作用和机理。结果表明:该菌具有嗜烃性能,在高温(65℃)和高压(10MPa)复合极端环境中,SL-1菌能够以原油为唯一碳源进行繁殖代谢,降解原油;代谢产生的生物表面活性剂具有乳化原油和改变岩石润湿性的作用,残余油被乳化分散成油滴;此外,该菌可降低油水界面张力和原油粘度,改善残余油的流变性。膜状残余油、柱状残余油以及盲端残余油等不同类型的残余油都能被有效驱替,最终提高原油采收率为12.84%。     

油井清蜡降黏剂的室内研究

开发研制环保、高效、多功能的油井清蜡降黏剂,是未来清防蜡剂的发展方向。在对不同性能表面活性剂及助剂对蜡的分散性、清蜡性能以及对大港油田稠油的降黏效果评价基础上,筛选出了性能好的烷基苯磺酸盐ABL、酰胺非离子表面活性剂XE 和木质素磺酸盐EM,通过正交试验优选出油井清蜡降黏剂配方组成,并对其综合性能进行了评价。结果表明,配方F6（ABL、XE）样品溶液稳定,且对蜡沉积物的分散性能好,具有较好的清蜡性能和降黏性能,对混合蜡的清蜡率和对大港油田稠油的降黏率分别达到98%和99%.     

含氟碳原油降凝剂的开发与应用

高含蜡原油管输过程中具有凝固点高、黏度大、流变性差的特点,为改善管输原油的低温流动性。借鉴徐高分子材料的应力诱导理论,利用氟碳表面活性剂电负性强、空间位阻大、相邻原子间排斥力大,吸附分散能力强的特征,"协同"性能不同的降凝剂复配得到含氟碳表面活性剂,筛选出最佳的配方和投药量,考察其对荆深管输原油降凝效果、加剂前后蜡晶形态。现场应用表明,含氟碳表面活性剂能将荆深管输原油凝固点降低12~14℃,同时,可使高凝原油井抽油机最大悬点负荷降低。满足了现场管输原油降凝降黏和高凝原油井正常生产。     

大芦湖油田微生物防蜡技术

胜利大芦湖油田原油含蜡多,凝点高,油井井筒结蜡严重。根据油藏特性从胜利采油院微生物中心菌种库筛选出两种芽孢杆菌、一种假单胞菌,均为兼性厌氧菌,将三种菌以不同比例混合得到三个混合菌组F18-C、F18-D、F18-F,可耐盐40g/L,生长pH4～9,生长温度30～90℃,适应含蜡10%～20%或大于20%,含沥青质10%～20%的原油,代谢脂肪酸、醇、二氧化碳。3种菌在隔氧条件下于60～65℃与4口井产出的原油、地层水一起培养7天后,原油降黏率和降凝幅度随油井而异,一般降黏率高于20%,最高超过55%,降凝幅度一般不小于5℃;与两口井原油作用后,菌液表面张力降低38.3%～34.1%;与菌液作用后的一口井的原油,碳数≥20的烷烃质量分数由0.22降至0.178。建立了一套油井微生物防蜡工艺,每隔20天从套管加入混合菌液200kg。2004年9月在5口井,2005年3月在9口井进行微生物防蜡试验均获得成功,2008年于60口井,2009年于98口井推广应用。2008年统计,60口井的洗井周期平均由32天延长至149天。含蜡量低(10%)而含胶质沥青质高(25%)的3口井,微生物防蜡效果差。图2表5参2     

Microbial treatment of waxy crude oil for mitigating wax precipitation and improving liquidity

The wax deposition of crude oil during transportation reduces the inner diameter, blocks the pipeline, and eventually increases the cost of petroleum production. This study reports a paraffin-degrading bacterial strain DG2 isolated from petroleum-contaminated soil. The effect of this strain on the removal of paraffin in crude oil was investigated. DG2, identified as Pseudomonas, produced biosurfactant that reduced the surface tension to 35.7?mN/m^?1 and exhibited high emulsification activity. Results of gas chromatography–mass spectrometry analysis of the waxy crude oil treated by DG2 showed decreased heavy hydrocarbon fractions (C25 and C32). The degradation test revealed that DG2 reduced the wax appearance temperature by 4.16?°C and the viscosity by 23% of the waxy crude oil. These findings indicate that paraffin-degradation strain DG2 may be used for effective paraffin biodegradation.     

长庆白豹油田固体防蜡技术研究

长庆白豹油田在油田的开发过程中存在着比较严重的结蜡问题,影响原油的正常生产。本文分析了白豹油田结蜡井的原油和蜡样:结蜡井原油中蜡含量高,在15%~20%,胶质和沥青质含量相对较小;蜡样碳数分布主要集中在C26~C39,以微晶蜡为主。应用原油动态结蜡率测试仪和流变仪两种方法测试了MH化学固体防蜡器的性能,它能降低高含蜡原油粘度>80%,降低原油凝点达11℃,防蜡率可达到75%以上。MH化学固体防蜡器在白豹油田现场试验15口油井。现场试验表明,化学固体防蜡器应用后,抽油机载荷明显低于加药前,且能有效地减少常规的清防蜡作业,延长检泵周期。     

Influencing factors governing paraffin wax deposition of heavy oil and research on wellbore paraffin remover

Abstract

Wax deposition is harmful to oil wells, especially for waxy heavy oils at low temperature. The influencing factors on wax deposition of heavy oil were studied and a kind of O/W emulsion type wellbore wax remover was investigated. The results showed that the wax deposition rate of Jinghe heavy oil increased with the increasing wax content and asphaltenes content but decreased with the increasing water content. The oil in water emulsion type paraffin remover was prepared and it showed both good wax dissolution and paraffin prevention ability and can save large quantities of solvent. The results of this study provides a possible way for waxy heavy oils to dissolve wax, to prevent wax deposition and reduce the viscosity of heavy oils by emulsification together, which is helpful to reduce the frequency of hot washing and enhance oil recovery for waxy heavy oils.     

石油烃降解菌Pseudomonas sp.及其生物表面活性剂对原油处理效果分析

从辽河油田受石油污染土壤中筛选出1株能够以液体石蜡为唯一碳源产生生物表面活性物质的W12#菌株,研究其对原油流动性的作用效果。结果表明：W12#菌株在生长代谢过程中产生的表面活性物质可以形成排油圈,其疏水性达到89.55%,乳化指数高达62.5%。通过傅里叶红外光谱仪测定,其代谢产物为糖脂类。原油经过 W12#菌株处理,蜡质量分数由9.78%降至6.39%,除蜡率为34.66%;在40 ℃条件下,降黏率达到63.75%,提高了原油的流动性能。     

含蜡原油热处理过程中若干组分的作用

本文研究了大庆、南阳原油中的胶质—沥青质,石蜡—正构烷烃和微晶等组分在含蜡原油热处理过程中的作用,从而指出:(1)只有当原油中含有石蜡和适量的胶质—沥青质时,才具备用热处理方法来改善其低温流动性能的可能性。(2)胶质—沥青质在含蜡原油中具有非常显著的分散作用增粘作用。它们通过吸附、共晶等作用改变原池中石蜡的结晶习性、形态及结构强度,从而取得降凝、降粘等效果。(3)各种原油中胶与正构烷烃之比在0.43～5.2之间,经过最佳条件热处理就可显示出热处理效果。胶—正烷烃比在0.6～3.0之间热处理效果最佳。(4)微晶蜡在含蜡原油热处理过程中,其本身不能显示热处理效果,当加热温度高达微晶蜡能在原油中大量溶解的温度时,在降温重结晶过程中,微晶蜡的析出将恶化热处理效果。     

Experimental study and a proposed new approach for thermodynamic modeling of wax precipitation in crude oil using a PC-SAFT model

A powerful method is necessary for thermodynamic modeling of wax phase behavior in crude oils,such as the perturbed-chain statistical associating fluid theory(PC-SAFT).In this work,a new approach based on the wax appearance temperature of crude oil was proposed to estimate PC-SAFT parameters in thermodynamic modeling of wax precipitation from crude oil.The proposed approach was verified using experimental data obtained in this work and also with those reported in the literature.In order to compare the performance of the PC-SAFT model with previous models,the wax precipitation experimental data were correlated using previous models such as the solid solution model and multi-solid phase model.The results showed that the PC-SAFT model can correlate more accurately the wax precipitation experimental data of crude oil than the previous models,with an absolute average deviation less than 0.4 %.Also,a series of dynamic experiments were carried out to determine the rheological behavior of waxy crude oil in the absence and presence of a flow improver such as ethylene–vinyl acetate copolymer.It was found that the apparent viscosity of waxy crude oil decreased with increasing shear rate.Also,the results showed that the performance of flow improver was dependent on its molecular weight.     

The action mechanism of wax inhibitors (WI) on pour point and viscosity of mixed waxy oil

Several methods had been used to minimize the problems caused by wax deposition in crude oil pipelines during the production and transportation of waxy crude oil; among them, the continuous addition of wax inhibitor (Abbreviation for WI) is considered as the most efficient one. This study uses two kinds of polymeric compounds as wax inhibitors with different solvents on the pour point and viscosity of mixed waxy oils evaluated. These four wax inhibitors defined as WI-1, WI-2, WI-3, WI-4, respectively. Five types of mixed waxy oil have the same wax content but different resin contents. Meanwhile, different resin contents affect the pour point and viscosity of mixed oils. Under different processing temperature, the viscosity of mixed oil measured when the temperature changes among 20 to 60°С. In this work, the results were that the effect of WI-1 and WI-3 relied on the resin content, processing temperature and dosing concentration. For mixed waxy oils, the pour point reductions contacted with dosing concentration and the resin content. The wax inhibitor shows good efficiency when the resin content was between 1.01 and 4.03 wt %. When the WI-1 added, the pour point of mixed oil-1 reduced 30°С at most and viscosity of mixed waxy oil greatly reduced. In sum, toluene as solvent shows better performance of wax inhibitors.     

EFFECT OF ASPHALTENE AND RESINS ON THE STABILITY OF WATER-IN-WAXY OIL EMULSIONS

Asphaltene, resins and paraffin waxes, their mutual interactions and their influence on the stability of water-in-oil emulsions have been studied. 20 wt % paraffin wax dissolved in decalin was used to model the waxy crude oil. Asphaltene and resins separated from a crude oil were used to stabilize the water-in-oil emulsions. Synthetic formation water was utilized as the aqueous phase of the emulsion. The emulsion stability increased with increasing the concentration of asphaltene with a subsequent decrease in the average particle size distribution of the emulsion. Resins alone are not capable of stabilizing the emulsion, however, in the presence of asphaltene they form very stable emulsions. Dynamic viscosity and pour point measurements provided evidence for resins-paraffin waxes interactions. Asphaltene in the form of solid aggregates form suitable nuclei for the wax crystallites to build over with a mechanism similar to that of paraffin wax crystal-modifiers. As asphaltene are polar in nature they are derived at the oil/water interface which was proved by the ability of asphaltene to reduce oil/water interfacial tension. Consequently, nucleation of the wax crystallites by asphaltene and resins at the interface will add to the thickness of the oil-water interfacial film and hence increase the stability of the emulsion.     

空心杆电加热技术在宝力格油田的应用

针对宝力格油田原油含蜡量高、凝固点高、黏度高,影响油井正常生产问题,应用了空心杆电加热技术,将专用加热电缆下入空心抽油杆内,使空心抽油杆和加热电缆组成集肤效应加热体,从而达到提高油管内原油温度、防止油管内壁结蜡、降低原油黏度、改变原油流动性的目的.加热电缆具有输出功率的可调性,可以根据不同的油井井况进行调整,达到所需的温度,实现自动化控制.该技术成功解决了油井停抽后不能启抽及油井定期清蜡问题,保证了油井的正常生产,取得了较好的开采效果和经济效益,对类似油田的开发具有一定的借鉴意义.