草舍油田CO2驱防气窜调驱体系研究及性能评价

草舍油田注CO2驱油开发后期,由于油藏渗透率级差大,CO2易通过大孔道窜至生产井,造成油井气油比上升,严重影响气驱效果。为了解决气窜问题,开展CO2驱防气窜调驱体系室内实验研究和性能评价,研制了一种适合于该油藏特征的聚合物凝胶–无机沉淀复合调驱体系。结果表明,聚合物凝胶–无机沉淀复合调驱体系气测封堵率达99.74%,突破压力为28643 kPa,封堵性能良好,能够满足草舍油田CO2驱防气窜调驱的需要,同时可以有效地降低作业成本,提高经济效益。该研究成果为提高草舍油田CO2驱防气窜工艺及整体开发水平提供了新的技术保证。

Research and performance evaluation of CO2 flooding gas channeling prevention and profile control flooding system in Caoshe oilfield

In the process of CO2 flooding in Caoshe oilfield,due to the large permeability difference of reservoir,CO2 is easily channeled to production wells through large channels,resulting in the increase of gas oil ratio of oil wells,which seriously affects the effect of gas drive.In order to solve the problem of gas channeling,a laboratory study and performance evaluation of CO2 flooding gas channeling prevention and profile control flooding system are carried out.A polymer gel inorganic precipitation composite flooding system suitable for reservoir characteristics is developed.The system is a combination of polymer gel system and inorganic precipitation system.The inorganic precipitating system can compensate for the decline of plugging rate after long time operation of polymer gel system,which can effectively reduce operation cost and increase economic benefits.The results show that the plugging rate of polymer gel inorganic precipitation composite flooding system is 99.74%,the breakthrough pressure is 28643 kPa,and the plugging performance is good.It can meet the needs of CO2 flooding and gas channeling and flooding in Caoshe oilfield.Meantime,it can effectively reduce the operating costs and improve the economic benefits.The research results provide a new technical guarantee for improving CO2 flooding and gas channeling prevention technology and overall development level in Caoshe oilfield.