| During the period of high water cut,oil control and deferring decline mainly depend on water shutoff profile control technology.The effect of water shutoff profile control is getting worse due to the influence of reservoir heterogeneity and multiple wheel profile control.It is difficult to play a role in the ultra-high water cut stage by relying solely on the plugging and adjusting macro-control.Therefore,it is necessary to assist the micro-control means to start the multi-pass residual oil and expand the micro-sweep degree to improve the plugging effect.According to the reservoir conditions of shengtuo oil field,a self-emulsifying deep tone drive system was optimized by screening and compounding.The static characteristics,displacement characteristics and microscopic mechanism of the system were studied through performance characterization,laboratory physical model oil displacement test,NMR seepage experiment and microscopic visualization experiment.The results show that under the condition of 85?,0.4% from deep emulsified oil displacement system in slightly under the action of external force,do not need to achieve ultra-low interfacial tension,can be emulsified crude oil,wash oil experiment in the process of the formation of the emulsion droplet distribution range is wide,the average particle size of 16.8 ?m,under the microscope droplet coalescence and bridge phenomenon.The indoor displacement test showed that the recovery range of the emulsifying system could be more than 25% after the water content in the core reached 98%.Nuclear magnetic resonance percolation experiment showed that the self-emulsifying deep titration system mainly displaces the remaining oil in the small and medium pores with the pore throat radius of 6-28 ?m.There are three kinds of micro-regulation and drive mechanism of self-emulsifying system,namely,differential force dynamic steering mechanism of capillary force,interfacial emulsification mechanism,and particle orifice and throat matching mechanism. |
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