长庆油田低渗透油藏聚合物微球深部调驱工艺参数优化

Optimization of Operational Parameters for Deep Displacement Involving Polymer Microspheres in Low Permeability Reservoirs of the Changqing Oilfield

为了提高聚合物微球深部调驱技术在长庆油田低渗透非均质性油藏的应用效果,在先导试验的基础上,在室内开展了不同粒径聚合物微球微观测试和模拟岩心流动试验,优选了低、中、高含水阶段的微球粒径,模拟优化了不同含水阶段聚合物微球深部调驱注入工艺参数及段塞组合。该技术在安塞、西峰、靖安、姬塬等油田43口井进行了现场应用,油井产量自然递减率平均降低3.0百分点以上,含水上升率平均降低2.2百分点,累计增油16 000t以上,累计降水21 400m^3。室内试验和现场应用结果表明,聚合物微球深部调驱技术对长庆油田低渗透油藏具有较好的适应性,解决了长庆油田低渗透油藏开发中存在的油井多向性见水、含水上升快和单井产能低等问题。

To enhance the application effect of deep displacement with polymer microspheres in low-permeability and heterogeneous reservoirs of the Changqing Oilfield,the lab tests for observing polymer microspheres of different sizes and simulating core flow have been performed on the bases of the pilot test,and optimized microsphere sizes in different stages with low,medium and high water cuts,respectively.The lab tests also determined the operation parameters and slug combinations for deep displacement by polymer microspheres in stages with various water cuts.The innovative technology has been deployed in 43 wells in Ansai,Xifeng,Jing’an,Jiyuan and other oilfields,with average natural productivity decline rates over 3.0 percentage point,average reduction of watercut increase rate of 2.2 percentage point,cumulative oil increment over 16 000 tons,cumulative water production drop of 21 400 m 3.Indoor and field test showed that deep displacement with polymer microspheres had better adaptability to low permeability reservoirs in the Changqing Oilfield,it has effectively eliminated the problems,including water production in different directions,quick increases in water cuts,low productivity of single wells etc.,in development of low permeability reservoirs in the Changqing Oilfield.