影响本源微生物采油效果的因素分析和对策

Main Factors Affecting Indigenous Microbial Flooding Efficiency and Countermeasures

基于大港港西和孔店两试验区油藏地质和开发状况，讨论了影响本源微生物驱油效果的6项主要因素。①油藏温度：港西油田（45℃）从注入混气营养液到见效的时间明显短于孔店油田（60℃），适宜本源微生物驱油油藏的温度应为30～55℃。②油藏潜力即油藏中有益茵落数量：给出了注水井返排液和油井产出液中有益茼（HOB．TGB，ZB,MGB）数量下限和有害茼（SRB）数量上限，现场数据表明港西潜力大于孔店，驱油效果也好于孔店。③激活体系：在接近极端条件的油藏，仪补充氮源和磷源是不够的，在长期注水油藏还需补充碳源如轻质油。④注入工艺：保证有充足的空气（氧）与营养液一起注入。施工次数增加时。激活强度应相应提高。⑤油井排液量：在使用电潜泵的孔店油田以120m^3／d为限，相当于水驱速度〈2m／d。⑥流体性质：矿化度应〈50g／L。原油含蜡量应〉5％，在原油含蜡量低的孔店油田，营养液中补充碳源后驱油效果改善。图2表3参11。

Six main factors affecting efficiency of indigenous microbial flooding （IMF） are presented and discussed on the basis of the results of Gangxi and Kongdian field trials as well as the reservoir characteristics and the developmental history. （1） Reservoir temperature, TR： the time duration from aerated nutrients injection to positive response appearing in oil wells at Gangxi of 45℃ is notably much shorter than at Kongdian of 60℃, the TR suitable to IMF is in range 30--55℃. （2） Reservoir polential, or population of advantageous bacterial flora： the practical limits of advantageous （HOB, TGB, ZB, and MGB） and harmful （SRB） flora population in backflows of injected fluids and in produced waters are tabulated, field monitoring data show greater potential and hence high IMF efficiency at Gangxi than at Kongdian. （3） Activating fluids, supply of N and P sources only is not enough for reservoirs under nearly extreme conditions, supply of C source such as light oil additionally is necessary in highly water flooded reservoirs. （4） Injecting technology： plenty of air （oxygen） should be injected together with nutrients, the intensity of activation should be boosted with increasing number of injections. （5） Well output： the output of wells working with electric submersible pumps at Kongdian should be 〈 120 m^3/d, that is, the speed of flooding water in reservoirs -〈 2 m/d. （6） Fluids characteristics： the TSD value in formation waters should be 〈50 g/L and the wax content in oil --〉5% ; at Kongdian, where the oil contains less wax, additional supply of C source has increased efficiency of IMF.