微生物采油技術(shù)在中國(guó)勝利油田羅801區(qū)塊試驗(yàn)a英文譯文2(存儲(chǔ)版)
【正文】 ry of Same Type Fault Block Oil Reservoir Blocks Luo9 and Luo801 of Luojia Oilfield are of the same type development units with similar reservoir conditions. Luo9 is situated to the south of Luo801, its main oilbearing stratum is S1 of sand section. It was put into operation in 1989, and switched to flooding recovery in 1990 (Table 2). The parameters of the two blocks are listed in the following table. Table 2 Reservoir data sheet of Blocks Luo9 and Luo801ItemBlockItemBlockLuo801 Luo9 Luo801 Luo9Reservoir typeLithologic structuralLithologic structuralReservoir temperature (℃)758095Oil bearing area (km2)Oil volume factorReserves(104t)291231Ground oil viscosity(mPas)Commissioning dateOriginal oil and gas ratio3289Injection dateRelative densityReservoir depth(m)1680192020202040Porosity (%)2123Net thickness(m)Oil saturation (%)6066Air permeability (103um2)174Formation water TDS (mg/L)50001100011000Oil freezing point（℃）112029Formation water typeNaHCO3NaHCO3By parison, it is clear that the nature of oil from Luo9 is better with the ground oil viscosity , formation oil viscosity , sulfur %, wax %, freezing point 29℃and its water and oil ratio is lower than that of Luo801. It was water injected during the initial stage so as to pensate the formation energy in time, ensuring the flooding development effect. Its benchmark flooding recovery is %. The reservoir temperature of Block Luo801 is ranging from 75℃ to 80℃, the viscosity of crude oil is relatively high with the ground oil viscosity , formation crude oil viscosity and wax %. It has been degassed by dissolved gas during the stage of natural energy development. At the preMEOR stage, its ground viscosity of crude oil reached , the viscosity difference between water and oil was relatively large. The water cut and recovery percentage curves of the two blocks show when recovery percentage is greater than 20%, Luo801 curve extends downward to form a “funnel”. The development data of Luo801after adopting MEOR can establish the recovery of Luo801 as %, better than flood development recovery in Luo9. This shows that MEOR effect is better than that of water flooding (Figure 5). Figure 5 Relationship between water cut and recovery percentage curves Characteristics of Microbial Activity in ReservoirsDuring the test, microorganisms and their metabolic production of the produced fluid have been sampled and analyzed regularly. The analysis result shows that after implementing MEOR, the bacterial density increases significantly in the produced fluid, gradually stabilizing at a magnitude 1034 / ml, while density of the sample before the test is only below 10 / ml. Analysis on concentration of acetate in the produced fluid discloses that average acetate concentration from the test area is 70mg/L before the test, which changes to , averaging mg/L, after the implementation of MEOR(Figure 6). During the test, the position of produced gas was analyzed and the relative concentration of methane gas was found to increase (Figure 7). The researchers believe that as the anaerobic anaerobicbacteria in the reservoir is activated, part of the acetate is utilized by anaerobic microorganisms to have the acetate concentration decrease. Monitoring on the methanobacterium content in the produced fluid reveals that the number of total bacteria and methanogenic bacteria levels continue to rise, which might be caused by acetatelike metabol
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