微生物采油需要进一步解决的问题

探讨制约微生物采油技术发展的关键问题，认为制约的主要因素不是油藏条件，而是研究技术本身不够完善。有两个问题值得注意：其一，对油藏中微生物结构认识的局限性。目前鉴定和分析微生物使用传统的微生物培养和显徽技术，只能发现生态环境中很少的一部分微生物，不能得到油藏产出液中有多少种微生物及其含量、所希望的微生物种群在其中是否属优势菌群等关键参数。其二，物理模拟驱油实验的局限性。目前的微生物驱油物理模拟研究基本沿用化学驱物理模拟研究设备和方法，一般使用人造岩心(国外多数使用天然岩心)，不能真实模拟油藏环境而准确反映微生物驱油的真实效果，研究得出的参数也就不能用于现场试验。最后，提出了微生物采油技术需要进一步解决的关键问题及其解决方法．参15     

Bacillus菌株提高碳酸盐油藏采收率的实验研究

微生物驱油技术(MEOR)近年来在世界多个油田取得了成功,大部分的实验室研究和现场应用都是针对砂岩油藏进行的,该技术在碳酸盐油藏中的研究很有限.两株Bacillus细菌在特定的温度下繁殖后,其代谢物被用于油水界面张力测试、玻璃模型驱油实验和碳酸盐岩心采收率实验.结果表明,细菌代谢物可大幅降低界面张力,并有效提高采收率.根据实验现象,微生物在碳酸盐岩石中的驱油机理是对高渗透率裂缝的选择性封堵.     

聚驱后微生物调驱菌种室内优选实验研究

简要介绍了聚合物驱后用微生物驱微生物菌种的筛选方法。考察了培养基溶液温度和pH值对微生物菌种生长的影响,结果表明,在温度45℃,pH值6．0-9．0时,微生物1号菌种2号菌种菌数均可达10^9个／mL。考察了微生物菌种驱油效果,结果表明,在含油饱和度78％以上的岩心中,微生物混合菌种含量2．5％时,聚合物驱后,再用微生物驱,驱油效率提高5．0％-8．7％。     

The Application of Microbial Enhanced Oil Recovery Technology in Shengli Oilfield

For the last 20 years Shengli oilfield has done research into the application of microbial enhanced oil recovery (MEOR). The authors summarize and analyze MEOR progress in mechanism research and field application in Shengli oilfield. The results indicate MEOR could improve oil recovery after water flooding and polymer flooding with multiple mechanisms. Cumulative oil increment of MEOR application on seven blocks was 212,366 t. The research and application of MEOR should concentrate on air assisted microbial flooding and indigenous microbial flooding in the future.     

Emulsifying action of Pseudomonas aeruginosa L6-1 and its metabolite with crude oil for oil recovery enhancement

Pseudomonas aeruginosa L6-1 was isolated from formation brine of Xinjiang Oilfield, China. Strain L6-1 showed perfect emulsification activity to crude oil and transformed mixture of crude oil and water into emulsion when crude oil was used as sole carbon source; thus, this method is a promising approach for emulsification and mobilization of residual oil in oil reservoirs and enhancement of its recovery. Average diameters of emulsified crude oil were between 1 and 8 µm. Interfacial tension of crude oil and water was reduced to 0.8 mN m^?1. Strain L6-1 produced 2.2 g L^?1 of rhamnolipid biosurfactant. Core flooding tests were carried out to investigate application potential of strain L6-1 for microbial enhanced oil recovery (MEOR). Enhanced oil recovery efficiencies ranged from 9.23% to 12.58% in both core models, with and without oxygen injection. These results revealed that strain L6-1 is a candidate functional microorganism for MEOR application.     

A Microbial-enhanced Oil Recovery Trial in Huabei Oilfield in China

This study discusses microbial-enhanced oil recovery (MEOR) application in Unit Jian-12 in Huabei Oilfield, China. The pilot field was a heavy oil reservoir (50°C, 204 mP.s) with high temperature (75.6°C). Unit Jian-12 was undergoing a waterflooding pattern; however, ordinary waterflooding no longer recovered residual oil efficiently that the MEOR method was strongly recommended in the stripper wells in the unit. A series of laboratory studies was conducted prior to the pilot test. The selected microbial consortia exhibited a positive effect on enhanced oil recovery and potential for application. A two-cycle trial was conducted and the production performance of the unit was monitored. The characteristics of crude oil were modified by biodegradation and the fluidity was improved. The residual oil in the formation was stimulated by the metabolic activities and metabolites, which greatly enhanced the displacement efficiency. In addition, an injection profile improvement was also observed in one injector (J 12–14) after the trial, indicating that the MEOR method could improve the heterogeneity of the reservoir and enhance the sweep efficiency. The results in this study were of academic and theoretic significance to microbial-enhanced oil recovery applications in heavy oil reservoirs.     

Using biosurfactant producing bacteria isolated from an Iranian oil field for application in microbial enhanced oil recovery

Microbial enhanced oil recovery (MEOR) is a useful technique to improve oil recovery from depleted oil reservoirs beyond primary and secondary recovery operations using bacteria and their metabolites. In the present study, the biosurfactant production potential of Bacillus licheniformis microorganisms that were isolated from oil samples of Zilaei reservoir in the southwest of Iran was explored under extreme conditions. Growth media with different temperatures of 40, 50, 60, and 70°C; salinities of 1, 3, 5, and 7 wt%; and yeast extract concentrations of 0.5, 1, 1.5, and 2 g/L were used to find the optimum growth conditions. The results demonstrated that bacteria grown in a mineral salt solution with temperature of 50°C, salinity of 1 wt% and yeast extract concentration of 1 g/L has the highest growth rate and therefore, these conditions are the optimum conditions for growing the introduced bacterium. This isolate was selected as the higher biosurfactant producer. The obtained biosurfactants by bacteria isolated in a medium with these conditions could reduce the interfacial tension of crude oil/water system from 36.8 to 0.93 mN/m and surface tension of water from 72 to 23.8 mN/m. The results of the core flooding tests showed that the tertiary oil recovery efficiency due to the injection of microorganisms was 13.7% of original oil in place and bacteria could reduce the oil viscosity by 41.242% at optimum conditions. Based on these results, the isolated microorganism is a promising candidate for the development of microbial oil recovery processes.     

Comparison of in-situ and ex-situ microbial enhanced oil recovery by strain Pseudomonas aeruginosa WJ-1 in laboratory sand-pack columns

Microbial enhanced oil recovery (MEOR) applies biotechnology to improve residual crude oil production from substratum reservoir. MEOR includes in-situ MEOR and ex-situ MEOR. The former utilizes microbial growth and metabolism in the reservoir, and the latter directly injects desired active products produced by microbes on the surface. Taking biosurfactant-producing strain Pseudomonas aeruginosa WJ-1 for research objects, in-situ enhanced oil recovery and ex-situ enhanced oil recovery by biosurfactant-producing strain WJ-1 were comparatively investigated in sand-pack columns.The results showed that P.aeruginosa WJ-1 really proliferated in sand-pack columns, produced 2.66 g/L of biosurfactant, altered wettability, reduced oil-water interfacial tension (IFT) and emulsified crude oil under simulated in-situ process. Results also showed that higher biosurfactant concentration, lower IFT, smaller average diameters of emulsified crude oil were obtained in in-situ enhanced oil recovery experiment than those in ex-situ enhance oil recovery experiment. Similar wettability alteration was observed in both in-situ and ex-situ enhanced oil recovery experiment. The flooding experiments in sand-pack columns revealed that the recovery of in-situ was 7.46%/7.32% OOIP (original oil in place), and the recovery of the ex-situ was 4.64%/4.49% OOIP. Therefore, in-situ approach showed greater potential in enhancing oil recovery in contrast with ex-situ approach. It is recommended that the stimulation of indigenous microorganisms rather than injection of microbial produced active products should be applied when MEOR technologies were employed.     

施工因素对微生物驱油效果影响的物理模拟研究

为了提高微生物驱油效果,开展了施工因素对微生物强化采油效果影响的物理模拟试验。利用"四因素三水平"正交试验设计方法,将注入方式、注入量、关井时间及重新开井时的微生物驱替速度分3个水平进行微生物驱替试验。驱替试验按在水驱之后注入微生物关井一段时间、再利用微生物发酵液驱替的顺序进行。评价各因素在不同水平组合下的采收率,从而优选出各因素最佳水平。利用正交试验设计方法设计的驱替试验结果优化,采用无机培养基和接种活化的菌液按照1:1的段塞注入方式,注入量为0.6倍孔隙体积,关井2 d,重新开井时的驱替速度为3倍孔隙体积/h时微生物强化采油效果最佳,这一最优组合方式在水驱产水率达到95%的基础上,采收率可以进一步提高近32百分点。这表明微生物注入方式等施工参数对微生物强化采油效果有较大影响,在实际施工中应先进行参数优化,以取得最佳强化采油效果。      

提高原油采收率试验菌的筛选和评价方法

本文根据大庆油田微生物地下发酵提高原油采收率先导性矿场试验中取得的认识，介绍了可用于ＭＥＯＲ菌种的基本条件，初步筛选方法及评价方法，探讨了筛选和评价ＭＥＯＲ菌种的研究工作今后的发展。     

微生物采油技术研究进展与发展趋势

近十几年来,主要有两方面原因促使微生物采油技术进入快速发展阶段,一是基于16S rRNA的微生物生态分析技术的应用,尤其是高通量测序技术的应用,实现了油藏极端环境微生物群落结构与动态演变规律的快速准确解析;二是以聚合物驱为主导的化学驱油技术的应用已经越过其高峰期,适合化学驱的油藏资源越来越少,对接替技术的迫切需求让微生...     

A thermotolerant surfactant-producing strain XT-1 applied for exogenous microbial enhanced oil recovery

A surfactant-producing strain XT-1 was isolated, identified and evaluated for exogenous microbial enhanced oil recovery (e-MEOR) in this study. The strain XT-1 was identified as bacillus subtilis through 16S-rDNA phylogenetic analysis, could grow and produce bio-surfactant at a wide temperature range from 20°C to 57°C with the highest surfactant yields of 830 mg/L. The bio-surfactant produced by the strain showed high degree of temperature-stability. Microbial core flooding experiment using three different types of crude oil at 35°C– 55°C indicated XT-1 can increase oil recovery of 6.88%?13.38%. These results demonstrate XT-1 have great potential for e-MEOR.     

聚合物驱后油藏激活内源微生物驱油现场试验

针对聚合物驱后油藏内源微生物的生长特点,对大庆油田萨南开发区南二区东部聚合物驱后典型油藏开展了激活内源微生物驱油现场试验。通过优选由玉米浆干粉、硝酸钠和磷酸氢二铵构成激活剂,与保护剂聚合物交替注入,并运用分子生态学末端限制性片段长度多态性方法分析了内源微生物激活前后群落结构的变化规律,研究了利用内源微生物驱油技术的可行性。现场试验结果表明：聚合物驱后油藏中有明显的产气增压效果;油藏驱动压力的动态变化及代谢产物气体组分CH₄和CO₂的δ¹³C同位素含量波动,验证了激活剂的加入促使油藏内源微生物微氧和无氧代谢交替进行;产出液的各项生化监测指标均有明显变化,激活后优势菌群为Pseudomonas、Thauera和Arcobacter,且丰度增高;试验区阶段累计增油3 068.13 t,含水率下降2.2% ,驱油增产效果明显。该试验的成功实施证明了聚合物驱后油藏采用激活内源微生物驱油的工艺方法是可行的,并为同类油藏进一步提高采收率提供了可借鉴的方法和途径。     

Microbial Enhanced Oil Recovery (MEOR)

Microbial enhanced oil recovery (MEOR) represents the use of microorganisms to extract the remaining oil from reservoirs. This technique has the potential to be cost-efficient in the extraction of oil remained trapped in capillary pores of the formation rock or in areas not swept by the classical or modern enhanced oil recovery (EOR) methods, such as combustion, steams, miscible displacement, caustic surfactant-polymers flooding, etc. Thus, MEOR was developed as an alternative method for the secondary and tertiary extraction of oil from reservoirs, since after the petroleum crises in 1973, the EOR methods became less profitable. Starting even from the pioneering stage of MEOR (1950s) studies were run on three broad areas, namely, injection, dispersion, and propagation of microorganisms in petroleum reservoirs; selective degradation of oil components to improve flow characteristics; and metabolites production by microorganisms and their effects.     

胜利油田微生物采油技术研究与应用进展

胜利油田微生物采油技术历经二十多年的室内研究和现场试验,机理研究取得深入认识,技术体系日趋完善,已进入工业化应用阶段.微生物界面趋向性、嗜烃乳化、界面润湿改性等主导驱油机理认识更加深入,并实现了量化表征,为菌种(群)改造和调控指明了方向;建立系统的油藏菌群结构分子生物学分析、采油功能菌激活调控、三维物理模拟驱油等微生物...     

Microbial Enhanced Oil Recovery (MEOR)

Abstract

Microbial enhanced oil recovery (MEOR) represents the use of microorganisms to extract the remaining oil from reservoirs. This technique has the potential to be cost-efficient in the extraction of oil remained trapped in capillary pores of the formation rock or in areas not swept by the classical or modern enhanced oil recovery (EOR) methods, such as combustion, steams, miscible displacement, caustic surfactant-polymers flooding, etc. Thus, MEOR was developed as an alternative method for the secondary and tertiary extraction of oil from reservoirs, since after the petroleum crises in 1973, the EOR methods became less profitable. Starting even from the pioneering stage of MEOR (1950s) studies were run on three broad areas, namely, injection, dispersion, and propagation of microorganisms in petroleum reservoirs; selective degradation of oil components to improve flow characteristics; and metabolites production by microorganisms and their effects.     

Organic nutrients for microbial enhanced oil recovery

Abstract

Glass vial tests were conducted to quickly screen nutrient mixtures for microbial enhanced oil recovery (MEOR). Common nutrients, such as food grade milk, were applied to 190 vial cultivation experiments. Five of the nutrient mixtures used in the glass vial tests showed no hydrogen sulfide (H₂S) production. These five were then assessed for oil recovery in a core flooding test. Four of the five nutrient mixtures showed an increased oil recovery of 10%, without H₂S production. Thus, the glass vial test was useful for screening through multiple nutrient mixtures quickly before analysis in the core flooding test.     

微生物采油技术的研究与应用

简要阐述了微生物采油技术、微生物采油技术的发展及微生物采油优势。介绍了用于微生物采油的自然菌和工程菌以及我国微生物采油菌的分离、筛选、产物分析、提高采收率机理研究的方法、采用手段和所取得的研究成果,在对微生物采油机理研究基础上提出了微生物采油数学模型。分析我国微生物采油矿场试验的成败后,指出微生物采油更适合于我国下列油藏;小于40℃的低温油藏;普通稠油油藏;含蜡油藏;含水小于80%的断块小油藏。     

微生物采油技术在国内外的研究现状及实例

介绍了微生物提高石油采收率的发展概况，基本原理与方法，探讨了ＭＥＯＲ技术的应用条件，综述了ＭＥＯＲ的矿场应用及效果。根据微生物处理的油层筛选标准，提出了中原油田部分油区可以利用ＭＥＯＲ的技术提高采收率。     

大庆油田微生物采油技术研究及应用

大庆油田微生物采油技术始于20世纪60年代,历经50多年的持续攻关,基础研究和现场应用均取得一定进展.研究发现微生物存在主动趋向原油、黏附原油、产表面活性剂乳化原油3种趋向原油方式,确定实验菌株以氧化方式降解烷烃、芳香烃的降解机理.在室内研究的基础上,针对特低渗透油田开展外源微生物现场试验,实施微生物吞吐试验93口井,...