Isolation, Identification And Crude-oil-degradating Characteristics On Thermophiles In Petroleum Reservoirs

Microbial Enhanced Oil Recovery(MEOR) is a novel comprehensive technique afterthree times of revolution of traditional EOR technologies, which utilize microorganisms andtheir metabolites to enhance oil recovery. Firstly, we described the development process andmechanisms of microbial enhanced oil recovery（MEOR）and its leading-edge in contrast tothe traditional oil extraction technology. Then we presented the pressing need to applythermophiles to oil extraction and described the necessity of thermophiles in enhanced oilrecovery and the research application status in China and abroad. Finally, according to today’sworldwide oil production situation, we proposed the idea of using thermophiles in the studyof recovering crude oil, focused on thermophiles and the mechanisms of its thermo stability,as well as the mechanisms of enhanced oil recovery and relevant thermophiles groups.In this study, we sampled the high temperature crude-oil from Henan and Zhongyuanoilfield reservoir recovery and used a variety of culture conditions and methods. Atotal of299strains of thermophiles were isolated and purified, classification and identification of thosestrains were performed on the basis of16S rDNA and the taxonomic status of strains wasinitially identified. Physiological and biochemical identification,16S rDNA gene sequencingand construction of phylogenetic tree were performed to identify the taxonomic position ofthree strains. Results show that strain P98-18A1belongs to Bacillus tequilensis10bTwith thesimilarity of99.724%, strain P388-53belongs to Bacillus altitudinis41KF2bTwith thesimilarity of99.932%, strain SHY-33belongs to Aeribacillus pallidus DSM3670Twith thesimilarity of99.661%.At the same time two ways of screening oil hydrocarbon degradation function strainwere used: the amplification of each strain’s hydrocarbon oil degradation function gene (alkB)and the method of using petroleum hydrocarbon as the sole carbon source in flask culture thenobserving the crude oil wave apparent phenomenon. After repeat screening thermophiliusstrains of crude oil degradation function, we finally screened the functional strain numberedP98-18A1. The effects of oil degradation of this strain were thoroughly analyzed, from thetotal hydrocarbon of the crude oil, the short chain of normal alkane’s degradation characteristics to physiological and biochemical characteristics of strains. Results show thatstrain P98-18A1has the selective abilities of using long chain of crude oil hydrocarbon andshort chain hydrocarbon under the different culture condition, but there are differencesbetween them. Comparisons of characteristics of degradation of short chain of normal alkanesof three strains from high temperature reservoir were analyzed in this study. Strain P98-18A1can effectively utilize of C6-C16n-alkanes and with a certain selective utilize ability of thechain longer than C16alkanes under the optimum conditions.In sum, we created the resource of lots of strains of thermophilic microorganisms,screened some strains with the abilities of degrading petroleum hydrocarbon, accumlated theexperience of the subsequent thermophilic microorganisms in oil production, and provided thestrains of the relevant thermophilic microorganisms, with a sinificant meaning of how toperfectly understand the reservoir environmental microbial structure, analyze thebiogeography characteristics of the formation of reservoir, and effectively utilize thethermophilic microorganisms in oil production.