Research On Oil Displacement Performance Of Microbial Active Agents

In this research,a variety of experimental methods are used to systematically evaluate the typical microbial active agents extracted and separated from the oil layers of Shengli Oilfield from the aspects of oil-water IFTs,emulsifying properties and wettability.To study the effect of oil displacement performance of the microbial active agents on oil displacement efficiency;to provide reference for exploring new technologies of the endogenous microbial active agents.Among the six microbial active agents evaluated,the active agent HTZ,which is mainly composed of sophorolipids,has the lowest extreme IFTs with crude oil(up to 10^-2m N/m),and its ability to emulsify and improve wettability is weak.Therefore,HTZ is an active agent whose main function is to reduce the oil-water IFTs.The active agent TH whose main component is lipopeptide has the strongest oil-water emulsifying ability（the emulsification coefficient reaches 0.81）,and has the strongest ability to improve wettability,and its extreme IFTs is only 10^-1m N/m It is a microbial active agent with strong emulsification and strong wetting improvement.The oil film displacement device was used to evaluate the oil film displacement ability of the microbial active agent with the oil film displacement efficiency as the index.For the original continuous oil film,among the six microbial active agents,the lowest IFTs sophorolipid active agent HTZ had the highest displacement efficiency.The residual oil film after the original continuous oil film was flooded was fully contacted with the active agent and then flooded.Among the six microbial active agents,the lipopeptide active agent TH,which was improved by strong emulsification and strong wetting,had a great effect on the displacement efficiency of the discontinuous residual oil film.From the experimental results,it can be inferred that reducing the oil-water IFTs plays a leading role in improving the displacement efficiency of continuous oil film;the key properties of the active agent that determine the displacement efficiency of discontinuous residual oil film are emulsification and improvement of wettability.The artificial inorganic cemented long core,which is non-toxic to biological agents,is used to carry out the simulation experiment of microbial active agent flooding.After water flooding,microbial active agent was used for flooding.Sophorolipid active agent HTZ and lipopeptide active agent TH both improved the microscopic oil displacement efficiency by more than 17%.Although the extreme oil-water IFTs of lipopeptide active agent TH is only in the order of 10^-1m N/m,due to its better oil-water emulsification and wetting improvement properties,the range of microscopic oil displacement efficiency is similar to that of low-tension sophorolipid active agent HTZ.It can be seen that,in addition to its ultra-low oil-water IFTs,the microbial active agent for oil displacement in the reservoir after water flooding,its strong emulsifying ability and strong wetting improvement characteristics are also the key performance indicators to determine the improvement of microscopic oil displacement efficiency.