Study On Migration Of Activator And Growth Of Microbe In Simulated Reservoir Condition

As the development of modern technology, the microbial enhanced oil recovery (MEOR) was upgraded and improved in the application. At present the MEOR was applied to ehhance recovery in many oil fields both in domestic and abroad, meanwhlie the effect was remarkble. But there were many problems and challenges need to be resolved. In the past the studies were mainly included the microbe were influenced by the physicochemical property of oil reservior, the strains filtration and identification of the educable stratal microflora in the stratum. But it was insufficient to studied the migration of activator in the porous media of oil reservior; the microbial community was changed in simulated reservoir condition; in addition the more intensive study of activator, microbe and metabolic product, effect of displacement of reservoir oil were necessary in the physical model tests. Based on the problems, this paper was carried out as follows:1 when the activator was injceted in the stratum, the porous media of reservoir must be had an effect on the migration of activator. If the activator was adsorbed, or even plugged in the porous media. The function of activator was not showed, and the growth of stratal microflora were restricted, at last the oil recovery was influenced. Though the study, the results as follows:1) when the activator was migrated in the porous media, the blockage was appeared in the different cores(unsaturated oil and saturated oil). The glucose was not influenced by the porous media, but the corn flour and starch could be impacted in the cores.In the saturated oil cores the corn flour was smoothly migrated than in the unsaturated oil cores. When the concentration was about 10 g·L-1, the pressure was max.1.7 MPa that was not produced blocking seriously. Besides changing the injection rate, the blocking was also became seriously both in saturated oil cores and unsaturated oil cores.2 Because the oil reservoir was high temperature and pressure, the traditional cultural method was not characterized the microbial community in the stratum. In this part the PCR-DGGE was used to analyzed the stratal microflora in simulated reservoir condition of Zhan 3 block in Shengli oil field. At last the reasonable substrate concentration was obtained, this may be provided reference and basis in the field used.1) The stratal microflora in the injected water and produced water was activated by different nutrition. From the bands of DGGE, it was concluded that the stratal microflora were growed when the time was 20 days, and that the microbe were obviously difference by the different activators.2) Further more the concentration of glucose was changed in the later experiment. The resuts showed that the microbe in the produced water was much more than in the injected water, at the same time the proper concentration of glucose was 5-7.5 g·L-1.3 In simulated reservior condition the microbial community structure, the effcet of displacement of oil, the metabolic products and the enivronmental parameters were studied by the physical model tests. Meanwhile the different formula and the condition of activating were also investigated.1) the experiment proved that the stratal microflora were growed after activated by the starch hydrolysates and the effect of displacement of oil was remarkable. Meanwhile when the incubation time was increased, the microbial community structure was also changed obviously. The population quantity of bacteria was reduced in the later period, however the archaebacteria were dominated in the later period and the species were tended to single. The entire experiment indicated that the transformation of microbe from aerobic to anaerobic in the oil deposit, this provided reasons for the change of stratal microflora and the dynamic change in the reservoir.2) The small molecule acid was tested by the gas chromatogram, the result showed that the acetic acid was decreased when the time was 70 days, this reflected the growth and metabolism of microorganism. At the same time the methane was increased in the later period. At the same time the accumulate of metabolite was important for enhanceing the oil recovery.