渤海P油田层内生成CO2调驱技术

In-Situ CO2 Generation Technology in Bohai P Oilfield

针对渤海P油田储层非均质性强、注水强度大,注入水突进和无效循环导致水驱开发效率低的问题,开展了层内生成CO2调驱技术研究。通过生气效率评价试验优选出最优生气体系,并利用Waring-Blender法和填砂管流动试验优选了配套发泡剂和稳定剂。室内试验结果表明:最优生气体系为生气剂A+释气剂D,其生气效率可达96.2%;发泡剂体系为0.2%发泡剂2+0.1%发泡剂5,其发泡体积为740 mL,析液半衰期为219 s;发泡体系中加入稳定剂1,对渗透率2 000~10 000 mD填砂模型的封堵率在90%以上。渤海P油田15个注采井组应用了层内生成CO2调驱技术,累计增注量69 986 m^3,累计增油量33 413 m^3,有效率达100%,有效期长达5个月。研究表明,层内生成CO2调驱技术技术对渤海P油田具有良好的适用性,解决了注水开发存在的问题。

In order to solve the problem of low water flooding development efficiency caused by strong reservoir heterogeneity,high water injection intensity,injected water influx and ineffective circulation in the Bohai P Oilfield,a study of in-situ CO2 generation technology was carried out.Firstly,the optimal gas generation system was selected by evaluating gas generation efficiency.Then,the foaming agent and blocking agent were screened by the Waring-Blender method and sandpack column flow experiment.Laboratory test results showed that gas generation efficiency could reach 96.2% when the gas system was blowing agent A+gas release agent D.The optimal foaming agent system was 0.2% foaming agent 2+0.1% foaming agent 5.The foaming volume was 740 mL and the half-life of dissolve-out liquid could be maintained for 219 seconds.When blocking agent 1 was added in the foaming system,the plugging rate could be maintained above 90% in the sandpack column with a permeability of 2000-10000 mD.The in-situ CO2 generation technology had been used in 15 injector producer pairs of the Bohai P Oilfield,resulting in the enhancement of accumulative oil recovery of 33413 m^3 by injecting 69986 m^3 of CO2 in total,with the effective rate reaching 100% and effective period up to 5 months,which indicated that in-situ CO2 generation technology had good applicability in Bohai P Oilfield and dissolves the problems existing in the water flood development of this field.