Abstract:

Ansai Oilfield is a oilfield with particularly low permeablilty,Chang-6 oil reservoir is the main one.Waterflooding started in the early producing stage.The geotemperature decreased 2.18℃～4.11℃ from 1986 to 1996 AD.,and crude oil viscosity increased 0.094～0.177 mPa ·s.Simulation result indicates that the maximum viscosity would not surpass 3.4 mPa·s (when geotemparature decreases from 50℃ to 20℃)by waterflooding.It is considered that waterflooding has very little influence on Chang-6 reservoir recovery efficiency.