Investigation On The Deep Profile Modification And Oil Displacement Under Microorganism Condition Of The Baolige Oil Field

Field test of deep profile control and flooding has been carried out for more than nine years in Baolige oilfield of Huabei Oilfield Company.Application of the polyacrylamide organic chrome crosslinking system in the oil-field has been proven,but some issues have been presented in the application,such as short time validity and unsteady gum performance.To address the key issues during the development,studies on deep profile control and flooding technology optimization have been conducted.Based on the comprehensive analyses on the geology characteristic and microorganism huff and puff of Baolige oilfield,considering the severe microorganism channeling and difficult microorganism field establishment due to the formation heterogeneity,through indoor research,gel formula and injection process meeting the requirement of deep profile control and flooding in different formation under microorganism environment have been developed to address the issues of horizontal and vertical reservoir and the inner layer and interlayer comflicts.For the overbank phase,the gel viscosity is controlled within 1000~1500 mPa·s For the main channel,the gel viscosity is controlled within 1500~2000 mPa·s.For the water channeling within fracture,the gel viscosity is controlled within 2000~3000 mPa·s.The gel experiment test has been conducted under reservoir temperature and fluid.The gel formula has been optimized based on gelling mechanism of organic chromium gel system and the effect of oxygen containing of water on the gel stability,so that to improve the control and flooding system stability.The optimal injection time has been determined based on the physical modeling.The injection process has been optimized mainly based on the injection concentration,injection velocity and injection volume.When the overall water content is within 40~80%,the oil recovery could be maintained at high level,and the conflicts of horizontal and vertical pay zone and the in-layer and interlayer could be relieved.The function of microorganism field in the formation could be fully played,so that to decrease crude oil viscosity and increase the sweep area of injected water,improving the whole development performance of Baolige oilfield.