海上弱固结砂岩储层膨胀注水工艺研究

Technical Study of Expansion Waterflooding in Offshore Weak Consolidated Sandstone Reservoirs

针对我国渤海弱固结砂岩油田注水井近井污染问题,提出膨胀注水解堵工艺技术,考虑随距井筒距离变化的污染程度,结合流固耦合效应,编写ABAQUS子程序,建立有限元分析模型,模拟渤海油田某注水井膨胀注水解堵效果。结果表明,在一定污染程度下,存在一个可达到解堵目的的最小注入速度,并在此基础上,建立渤海弱固结砂岩储层膨胀注水图版。结合实际,提出配套阶梯式膨胀注水工艺,增强现场运用的安全性和灵活性。

For the near well plugging problem of injection wells in weak consolidated oilfield in Bohai Area,a technique of expansion waterflooding for blocking removal was proposed.Combined with the degree of contamination of variation with distance and the matching effect of fluid-solid coupling,a finite element analysis model is established with ABAQUS subroutine to simulate the effect of expansion waterflooding in a water injection well in Bohai Area.The result shows that a minimal injection rate can be obtained for plugging removal at a certain degree of contamination.Based on the study,a plot is established waterflooding in weak consolidated reservoirs.In combination with practical application,a technique of stepped expansion waterflooding is proposed to enhance the security and flexibility in oilfield application.