【作者】 孔祥平；

【导师】 王修林； 李希明； 包木太；

【作者基本信息】 中国海洋大学 ， 海洋化学， 2004， 硕士

【摘要】 在对胜利油田单12区块内源微生物群落结构分析的基础上，以内源微生物选择性激活剂配方筛选为重点，通过物理模拟驱油试验对内源微生物采油技术进行了较为系统的研究，为单12区块实施内源微生物采油技术奠定了基础。具体研究内容如下： 1．胜利油田单12区块内源微生物群落结构分析 利用选择性培养基，采用最大或然数(most probably number，MPN)法和倾注平板法对单12区块注入水和5口油井产出水中的主要内源微生物群落结构进行了分析。结果表明，单12区块内源微生物类群较为丰富，石油烃降解菌、脱氮菌、产甲烷菌等有益菌和硫酸盐还原菌、铁细菌、硫细菌、腐生菌等有害菌普遍存在，各类菌的含量不同，总体含量较低；可利用微生物间生存竞争关系，通过注入合适的营养物，选择性地激活有益菌，抑制有害菌，提高原油采收率。 2．胜利油田单12区块内源微生物群落选择性激活剂筛选 以俄罗斯科学家伊万诺夫(Ivanov)提出的好氧微生物—厌氧微生物演替降解石油的两阶段生物过程为理论基础，依据经济实用的原则，以活菌数、培养液表面张力降低率和原油乳化降解率为考察指标，筛选出了以玉米糖为主体的ST-12Y激活剂配方。该配方可以将单12区块的有益菌较大程度的激活，其中石油烃降解菌提高了4个数量级，脱氮菌和产甲烷菌提高了2个数量级；而非有益菌基本上处于抑制状态。内源微生物激活后，原油中短链饱和烃组分增加，长链饱和烃组分减少，出现明显的乳化现象，原油的流动性增强。内源微生物培养过程中醋酸根含量的变化反映了培养液中好氧微生物—厌氧微生物的变化。 3．内源微生物物理模拟驱油试验研究 采用单12区块原油和原生水，模拟地层条件，进行了内源微生物物理模拟驱油试验研究，对残余油采收率、系统压力、醋酸根含量、生物气产量及组成进行了检测。结果表明，采用空气辅助(液气比1：10)激活好氧微生物，经过36天的培养驱替，残余油采收率提高了4.7％；依赖于整个油层生态系统的改善，在激活的厌氧微生物的主导作用下，经过两轮次77天的培养驱替，残余油采收摘要率提高了8.3%;试验结果验证了注水油层中好氧微生物一厌氧微生物演替降解石油的两阶段生物过程，生物气中甲烷的含量随培养时间的增加而增加，最高达74.45%;而始终未检测出硫化氢，说明硫化氢的产生得到了有效抑制。以上结果表明胜利油田单12区块适合实施内源微生物采油技术。 本论文的研究成果将为内源微生物采油矿场试验设计提供一定的理论基础和技术支撑。目前已应用于胜利油田单12区块单12一16井组内源微生物驱油矿场试验方案设计，矿场试验正在进行中。更多还原

【Abstract】 Based on the analysis of community structure of indigenous microorganisms at S12 block in Shengli Oilfield, a formula of selective-activating agent was screened out and the feasibility of activating indigenous microorganisms at S12 block to enhance oil recovery was studied through physical simulation experiments. The main research contents were listed as follows:1. Analysis of community structure of indigenous microorganisms at S12 block in Shengli OilfieldWith selected media, the community structure of indigenous microorganisms in six water samples (including recycled produced water for flooding reservoir at S12 block in Shengli Oilfield and produced waters from five oil wells of the reservoir) was analyzed. The results proved the bio-diversity of microorganisms at S12 block, including both the beneficial bacteria (hydrocarbon degrading, denitrifying, and methane-producing bacteria) and the detrimental bacteria (iron, sulfur, sulfate reducing, and total growth bacteria). It supports the possibility that the oil recovery at S12 block can be enhanced by injecting proper nutrients, selectively activating the beneficial stratal microorganisms and inhibiting the detrimental ones in the reservoir formations.2. Screening of activation agent to stimulate the stratal microflora selectively at S12 block in Shengli OilfieldBased on the theory of bio-inversion of oil in reservoir by Ivanov, the activation agent ST-12Y, which was mainly made up of corn syrup, was screened out by considering the population of living bacteria, surface-tension reducing efficiency, emulsification efficiency and the economical budget. It could effectively activate the beneficial bacteria and restrain the detrimental bacteria with desirable results. The hydrocarbon degrading bacteria increased from 1-10 to 105-106 cell/ml, theABSTRACTdenitrifying bacteria increased from below 10 to 103-104 cell/ml, and the methane-producing bacteria increased from below 10 to 10-102 cell/ml. After the activation of the indigenous microorganisms, an increase of saturated short-chain hydrocarbons and a decrease of saturated long-chain hydrocarbons content in the crude oil occurred. Thus the enhancement of hydrocarbon emulsification and the fluidity were observed obviously. The change of acetate concentration reflected the succession from aerobic to anaerobic microorganisms in the culture.3. Physical simulation study on indigenous microbial floodingIn order to determine the oil recovery efficiency from waterflooded residual oil, the change of system pressure, the concentration of acetate, the yield and the composition of biogas, the indigenous microbial flooding process in stratum was simulated through laboratory experiments with the crude oil and connate water from S12 block. The results showed that the oil recovery from residual oil had been increased by 4.7% after 36 days culture by adopting air-assistant technique (liquid/air 1:10 v:v). Based on the synergistic effect of the ecosystem of reservoir, 8.3% of the in-situ residual oil after waterflooding was recovered after two treatments of 77 days, mainly depending on the anaerobic microorganisms. The results strongly support the theory of the bio-inversion of oil in reservoir. The concentration of methane in the biogas increased with incubation time and the maximum concentration could reach 74.45%. The H2S was not checked out throughout the experiment, which showed that the yield of H2S had been effectively restrained.The results of this thesis will hopefully provide the theoretical basis and technologic support for the design of enhanced oil recovery project by activating indigenous microorganisms. And it has been put into use in-situ at S`I2 block.更多还原