Experimental Study Of Microbial Flooding In High Teamperature And High Pressure

With the development of the microbial enhanced oil recovery (MEOR), it becomes more and more important to study the percolation characteristic and components of crude oils before and after biodegradation by microbes, which can reveal effectively the interactions between crude oils and microorganisms and their metabolites. Obtained results could add our understandings of the mechanism related to the microbial enhanced oil recovery.In order to know the multi-phase seepage law and the flooding mechanism in microbial flooding process and subsequent water flooding process, the oil-water relative permeability curves of Sheng Ii reservoir in Qing He area before and after the microbial flooding of indigenous bacteria and indigenous bacteria+GS1were measured under the reservoir condition of50’C and15MPa.the irreducible water saturation, the residual oil saturation, the absolute permeability and the relative permeability of cores before and after the microbial flooding are compared. The results show that, compared with before microbial flooding, the irreducible water saturation increases, the residual oil saturation decreases, the absolute permeability changes a little and the water saturation at equal permeability point obviously increase.Thin-layer chromatography/flame ionization detector (TLC/FID), chromatography, mass spectrometric (GC-MS) were used to analyze and characterize the7samples from Sheng Ii oil-fields and Da Qing oil-fields in the study. Four components in crude oil is given priority to with saturated hydrocarbon and aromatic hydrocarbon, microbial action after different degrees of changes have taken place in each component content. Qing He oil testing results showed that exogenous bacteria GS1is helpful for other components in crude oil as saturated hydrocarbon conversion; Pr/Ph、 Pr/nC17、 Ph/nC18description and exogenous bacteria indigenous fungus into GS1appear to the degradation of crude oil has strong effect, especially the exogenous bacteria GS1∑nC21-/∑nC22++value increases, the carbon peak shift to the left, and exogenous bacteria indigenous fungus that GS1can effectively degrade Qing He oil are long chain alkanes. Da Qing crude oil testing results showed that in different under the action of activation agent, four components in the same change trend. Pr/Ph-. Pr/nC17、Ph/nC18values increase slightly, weak degree of microbial effects on crude oil.∑nC21-/∑nC22+value decreases, and shows that the relative contents of crude oil are long chain alkanes increases, especially under the no.2and no.3action of activation agent. Main carbon moves to the irghtto further illustrate the relative contents of crude oil are long chain alkanes. Aromaticcompounds evident changes of naphthalene seires and seires, the second seires of biphenylcompounds are easy to microbial degradation, at the same time heterocyclic aromatichydrocarbons, such as the two coumarone in Qing He oil has a certain amount ofdegradation.The series of naphthalene and philippine before and after biodegradation changedsignificantly. The biphenyl and the heterocyclic aromatics, and the dibenzofurans in the oilfrom Henan oil-filed, were also degraded.