大庆油田微生物采油现场试验进展

本文介绍近十几年以来大庆油田利用具有产气、降解原油、产生物表面活性剂及堵调性能的菌剂,通过地下发酵,开展微生物采油现场试验取得的进展.分析了该项技术适用的油藏条件和应用特点.截止到2012年底,应用微生物采油技术增产原油达12×104 t.其中微生物单井吞吐518口,累计增油6.3×104t,实施微生物驱和调驱项目10项(45个井组),累计增油5.7×104 t,为大庆油田稳产发挥了重要作用.     

大庆聚驱后油藏微生物群落结构分析

目的:进一步研究大庆聚驱后油藏微生物种类.方法:应用T-RFLP方法比较系统地分析比较了聚驱后油藏微生物多样性,分析了与采油功能相关的主要微生物组成,初步研究了聚驱后油藏微生物分布特点及规律.结果:利用聚驱后油藏细菌群落16S rDNA构建克隆文库,共挑取了49个阳性克隆,T-RFLP分型结果,共出现21个不同类型.所得的序列在Genbank中比对的结果表明细菌克隆可分为5个类群,分属于变形杆菌、拟杆菌、脱铁杆菌、厚壁菌以及未确定分类的类群;同时构建了聚驱后油藏古菌群落16S rDNA的克隆文库,共挑取了48个阳性克隆,根据T-RF分型结果共有5个类群,构建的古菌克隆文库的12个阳性克隆分属5个不同的类群,这些克隆和产甲烷菌亲缘关系很近.结论:该研究为大庆油田本源微生物采油技术的应用提供了可靠的理论依据.     

微生物提高原油采出率的室内研究

微生物采油技术是一种提高原油采出率的卓有成效的方法。本文通过在实验室条件下模拟江苏油田韦4区块的储层情况,进行岩芯的驱替实验,对微生物采油技术在韦4区块的运用作了一些研究和评价,并得出应用结论,为该技术在现场的实验奠定了理论基础。     

油藏微生物的代谢特征与提高原油采收率技术

油藏是一个高温、高压、少氧、寡营养和封闭的极端环境,油田经过多年注水开发后,在油藏内部形成了相对稳定的微生物群落体系,这些微生物以石油烃分解为起始,形成了一个复杂的食物链,对油藏碳、硫和金属离子的元素地球化学循环起着非常重要的作用。微生物提高原油采收率技术(MEOR)是利用微生物及其代谢产物与油藏和原油发生作用来提高原油采收率的一种新技术,具有成本低、适应性强和环境友好等特点,因此有望成为未来化学驱后油藏和高含水油藏进一步提高采收率的重要手段。对油藏内源微生物及其介导的生化反应,微生物采油原理、发展历程和现场试验进行综述,并提出了未来的发展方向。     

厌氧产表面活性剂微生物提高原油采收率的研究进展

微生物强化采油(microbial enhanced oil recovery,MEOR)是近年来在国内外发展迅速的一项提高原油采收率技术。微生物在油藏中高效生产表面活性剂等驱油物质是微生物采油技术成功实施的关键之一。然而,油藏的缺/厌氧环境严重影响好氧表面活性剂产生菌在油藏原位的生存与代谢活性;油藏注空气会增加开采成本,且注入空气的作用时效和范围难以确定。因此,开发厌氧产表面活性剂菌种资源并强化其驱油效率对于提高原油采收率具有重要意义。本文综述了国内外近年来利用厌氧产表面活性剂微生物提高原油采收率的研究进展,简述了微生物厌氧产表面活性剂的相关驱油机理、菌种资源开发现状以及油藏原位驱油应用进展,并对当前的研究提出了一些思考。     

油藏微生物群落研究的方法学

油藏微生物群落的解析和认知是开发和应用微生物采油技术的基础。利用各种提高油藏微生物可培养性的方法和非培养技术解析不同油藏微生物的群落结构、功能和多样性,对定向调控油藏微生物群落、开发和应用有效微生物驱油技术具有重要的指导意义。通过调查新近发展的提高微生物可培养性的方法和措施以及不依赖于培养的分子微生物生态学技术,总结了油藏微生物群落研究方法学的最新进展。提高微生物可培养性的方法和措施主要通过模拟微生物的生存环境,减少富营养的毒害作用、添加信号分子维持微生物细胞间的作用和提供新型电子供体和受体等手段采用稀释法、高通量培养法等方法得以实现;不依赖于培养的分子微生物生态学技术主要包括荧光原位杂交、末端限制性片断长度多态性分析、变性梯度凝胶电泳和构建克隆文库等技术。这些方法学的进展为更有效的获得各种油藏微生物资源、调控油藏微生物群落以提高石油采收率提供理论指导。     

内源微生物采油技术的历史与现状

内源微生物采油技术的研究已有多年的历史 ,因其工艺简单、成本低而具有较好的发展前景。综述了国内外在该领域的基础研究进展和矿场试验情况。     

油藏微生物及其在石油工业中的应用

油藏是一种特殊环境,其高温、高压、高矿化度、无氧、多孔介质及其流体等因素对微生物的存活及生长繁殖都会产生明显影响。油藏极端环境对微生物群落结构组成和数量也会有大的影响。该文介绍了与微生物采油关系紧密的微生物群落的生理生化特征及其多样性。主要有烃降解菌、发酵菌、硫酸盐还原菌及产甲烷菌。还介绍了激活本源微生物和筛选外源微生物在提高石油采收率方面的应用。最后就分子生物技术在研究油藏中可培养微生物和未培养微生物中的应用进行了讨论。     

微生物在油藏中的地球化学活动——提高采油

微生物提高采油方法的发展是以研究栖息在油层中的微生物的地球化学活动及其生物学为基础的。 苏联开始研究石油微生物区系可追溯到1926年,在那年首先在油层水中发现了细菌。这种新生境的分析揭示了微生物在油藏中的分布有一定的规律。     

用PCR-DGGE 方法分析渤海原油降解过程微生物群落结构变化

针对渤海油田原油粘度大、含水上升快、常规措施作用不明显的特点, 采用微生物采油技术开展提高稠油采收率研究。通过室内物理模拟实验, 结合变性梯度凝胶电泳(Denature Gradient Gel Electrophoresis, DGGE) 技术及原油粘度测定分析研究均质、非均质岩心驱替前后稠油采收率变化、微生物群落丰度结构变化、原油理化性质变化, 尝试分析微生物提高稠油采收率机理。物模结果表明: 微生物采油体系能够有效提高稠油采收率, 在均质岩心和非均质岩心驱替中, 微生物体系可分别提高采收率14.4%、29.4%; DGGE 结果显示: 微生物体系出口端丰度明显高于注入端;原油粘度测定显示: 出口端原油粘度明显下降。三者结合说明微生物体系能够利用稠油作为碳源, 在地层环境中生长,菌种在地层中有较强的适应性, 同时能够降低稠油粘度, 提高其采收率。     

Recent Advances in Petroleum Microbiology

Recent advances in molecular biology have extended our understanding of the metabolic processes related to microbial transformation of petroleum hydrocarbons. The physiological responses of microorganisms to the presence of hydrocarbons, including cell surface alterations and adaptive mechanisms for uptake and efflux of these substrates, have been characterized. New molecular techniques have enhanced our ability to investigate the dynamics of microbial communities in petroleum-impacted ecosystems. By establishing conditions which maximize rates and extents of microbial growth, hydrocarbon access, and transformation, highly accelerated and bioreactor-based petroleum waste degradation processes have been implemented. Biofilters capable of removing and biodegrading volatile petroleum contaminants in air streams with short substrate-microbe contact times (<60 s) are being used effectively. Microbes are being injected into partially spent petroleum reservoirs to enhance oil recovery. However, these microbial processes have not exhibited consistent and effective performance, primarily because of our inability to control conditions in the subsurface environment. Microbes may be exploited to break stable oilfield emulsions to produce pipeline quality oil. There is interest in replacing physical oil desulfurization processes with biodesulfurization methods through promotion of selective sulfur removal without degradation of associated carbon moieties. However, since microbes require an environment containing some water, a two-phase oil-water system must be established to optimize contact between the microbes and the hydrocarbon, and such an emulsion is not easily created with viscous crude oil. This challenge may be circumvented by application of the technology to more refined gasoline and diesel substrates, where aqueous-hydrocarbon emulsions are more easily generated. Molecular approaches are being used to broaden the substrate specificity and increase the rates and extents of desulfurization. Bacterial processes are being commercialized for removal of H₂S and sulfoxides from petrochemical waste streams. Microbes also have potential for use in removal of nitrogen from crude oil leading to reduced nitric oxide emissions provided that technical problems similar to those experienced in biodesulfurization can be solved. Enzymes are being exploited to produce added-value products from petroleum substrates, and bacterial biosensors are being used to analyze petroleum-contaminated environments.     

海洋石油降解微生物及其降解机理

微生物修复作为一种新型环保的生物修复技术,已成为海洋石油污染生物修复的核心技术。对海洋石油降解微生物的种类即细菌、蓝藻、真菌以及藻类进行了总结,对微生物对石油烃的降解途径与降解机理进行了综述。微生物降解烷烃的过程包括末端氧化、烷基氢过氧化物以及环己烷降解3种形式。微生物对芳香烃的降解是通过芳香烃被氧化酶氧化导致苯环开环来实现的。微生物对多环芳烃的降解是在单加氧酶或双加氧酶的催化作用下被最终降解为二氧化碳和水而被分解。并对影响石油烃降解微生物的因素包括温度、营养物质等因素进行了分析。     

Enumeration of petroleum-degrading microorganisms.

A variety of factors, including concentration of oil, antibiotics, dyes, and inoculum washes, were examined to determine their effect on the total counts of microorganisms on oil-containing media. The media found to be best for enumerating petroleum-degrading microorganisms contained 0.5% (vol/vol) oil and 0.003% phenol red, with Fungizone added for isolating bacteria and streptomycin and tetracycline added for isolating yeasts and fungi. Washing the inoculum did not improve recovery of petroleum degraders. Specifically, silica gel-oil medium and a yeast medium are recommended for enumeration of petroleum-degrading bacteria and yeasts and fungi, respectively. It is suggested that counts of petroleum degraders be expressed as percentage of the total population rather than total numbers of petroleum degraders per se. Incubation temperature and presence of oil was found to influence the numbers of petroleum-degrading microorganisms at a given sampling site.     

Surfactants in microbiology and biotechnology: Part 2. Application aspects

Surfactants are amphiphilic compounds which can reduce surface and interfacial tensions by accumulating at the interface of immiscible fluids and increase the solubility, mobility, bioavailability and subsequent biodegradation of hydrophobic or insoluble organic compounds. Chemically synthesized surfactants are commonly used in the petroleum, food and pharmaceutical industries as emulsifiers and wetting agents. Biosurfactants produced by some microorganisms are becoming important biotechnology products for industrial and medical applications due to their specific modes of action, low toxicity, relative ease of preparation and widespread applicability. They can be used as emulsifiers, de-emulsifiers, wetting and foaming agents, functional food ingredients and as detergents in petroleum, petrochemicals, environmental management, agrochemicals, foods and beverages, cosmetics and pharmaceuticals, and in the mining and metallurgical industries. Addition of a surfactant of chemical or biological origin accelerates or sometimes inhibits the bioremediation of pollutants. Surfactants also play an important role in enhanced oil recovery by increasing the apparent solubility of petroleum components and effectively reducing the interfacial tensions of oil and water in situ. However, the effects of surfactants on bioremediation cannot be predicted in the absence of empirical evidence because surfactants sometimes stimulate bioremediation and sometimes inhibit it. For medical applications, biosurfactants are useful as antimicrobial agents and immunomodulatory molecules. Beneficial applications of chemical surfactants and biosurfactants in various industries are discussed in this review.     

油藏微生物及其压力适应机制

目前我国油田开发主要处于高含水后期,微生物驱提高石油采收率技术(MEOR)以低成本、环境友好等独特的优势引起了石油工业界的重视。实际上,经过半个多世纪的发展,MEOR已经成为提高采收率的重要前沿技术。高压是油藏的主要环境特征,在影响油藏微生物生存与活性等方面具有重要作用。本文从油藏及其微生物的主要特征、微生物对高压环境的适应机制以及高压下微生物降解烃的代谢特征等方面进行了综述。介绍了对油藏微生物资源、群落结构、微生物在油水相中分布的认识,微生物乳化原油机制,以及微生物在油藏厌氧环境中协同代谢、受温度和压力影响的特点,并列举了MEOR的矿场应用。在高压适应机制上,微生物主要通过改变和调整细胞膜结构、增加胞内脂质组分和表达胞内特殊酶等作用来实现对压力的适应;在高压下烃降解微生物代谢速率低于常压,而且耐压菌和嗜压菌具有不同的烃降解效率。     

Effect of Photosynthetic Bacteria and Compost on Degradation of Petroleum Products in Soil

Addition of diesel fuel and waste engine oil to soil was found to stimulate hydrocarbon-oxidizing microorganisms. Corynebacteria constitute a large group of hydrocarbon-oxidizing microorganisms. Addition of a liquid culture of photosynthetic bacteria to soil facilitates degradation of petroleum products and also stimulates growth of hydrocarbon-oxidizing microorganisms. Combined addition of photosynthetic bacteria and compost to soil polluted with petroleum products produces a greater increase in the number of hydrocarbon-oxidizing bacteria and substantially augments the rate of pollutant degradation.     

Effect of photosynthetic bacteria and compost on degradation of petroleum products in soil

Addition of diesel fuel and waste engine oil to soil was found to cause biostimulation of hydrocarbon-oxidizing microorganisms. Corynebacteria constitute a large group of hydrocarbon-oxidizing microorganisms. Addition of a liquid culture of photosynthetic bacteria to soil not only facilitates degradation of petroleum products, but also stimulates growth of hydrocarbon-oxidizing microorganisms. Combined addition of photosynthetic bacteria and compost to soil polluted with petroleum products causes even a more significant increase in the count of hydrocarbon-oxidizing bacteria and substantially increases the rate of pollutant degradation.     

Treatment of petroleum industry oil sludge in soil

Petroleum refining unavoidably generates large volumes of oil sludge. The environmentally acceptable disposal of oil sludge is a current challenge to the petroleum industry. Many soil microorganisms possess a remarkable capacity to degrade various components of crude oil. The land treatment of oil sludge — land farming — is an environmentally acceptable and economically feasible disposal method. The development of efficient hydrocarbon-degrading microorganisms and their use for cleaning oil sludge in soil are discussed.     

Biodegradation of crude oil by soil microorganisms in the tropic

Five microorganisms, three bacteria and two yeasts, capable of degrading Tapis light crude oil were isolated from oil-contaminated soil in Bangkok, Thailand. Soil enrichment culture was done by inoculating the soil in mineral salt medium with 0.5% v/v Tapis crude oil as the sole carbon source. Crude oil biodegradation was measured by gas chromatography method. Five strains of pure microorganisms with petroleum degrading ability were isolated: three were bacteria and the other two were yeasts. Candida tropicalis strains 7Y and 15Y were identified as efficient oil degraders. Strain 15Y was more efficient, it was able to reduce 87.3% of the total petroleum or 99.6% of n-alkanes within the 7-day incubation period at room temperature of 25 ± 2 °C.     

Bioremediation of oil contaminated beach sediments using indigenous microorganisms in singapore

The potential of using indigenous microorganisms in beach sediments to degrade petroleum hydrocarbons emanating from marine oil spillages in the Straits of Singapore was investigated. A field trial was conducted using oil contaminated beach sediments from Pulau Semakau – a small island 15 km south of Singapore. The results clearly show that the addition of inorganic nutrients to beach sediments significantly enhanced the activity of indigenous microorganisms (measured using the dehydrogenase enzyme assay and viable cell count techniques), as well as the removal of total recoverable petroleum hydrocarbons (TRPH) over a 50-day study period (with up to 44% in the case of nutrient addition). The potential of exploiting in-situ bioremediation techniques for oil spill clean-up operations in tropical marine environments is discussed.