渤海油田多轮次层内生成CO2调驱效果优化

Multi-round profile control effect optimization of in-situ carbon dioxide generation in Bohai Oilfield

杨寨 郑玉飞2

中海石油（中国）有限公司天津分公司辽东作业公司，天津 300452 中海油田服务股份有限公司油田生产事业部，天津 300459

Liaodong Operation Company, Tianjin Branch of CNOOC Ltd., Tianjin 300452, China Production Department of China Oilfield Services Limited, Tanggu 300459, China

为解决渤海油田多轮次层内生成CO2调驱后增油效果逐渐变差的问题，通过岩心驱替实验分析了其原因，并对比了不同封堵体系对调驱效果的改善作用。研究表明：1轮次层内生成CO2调驱可使原油采出程度在水驱基础上提高25.61百分点，2轮次调驱采出程度在1轮次基础上仅提高0.38百分点，3轮次调驱已无增油效果；在3轮次调驱前注入0.2 PV的聚合物，增油效果提高不明显，而注入同样体积的凝胶体系，采出程度比只进行3轮次层内生成CO2调驱提高10.19百分点，表明凝胶体系能够有效封堵高渗层，使后续层内生成CO2调驱溶液转向低渗层，从而显著改善多轮次层内生成CO2调驱效果。研究结果为在渤海油田强非均质性储层开展多轮次层内生成CO2调驱提供了参考依据。

In order to solve the problem that oil increase effect gradually decreases after multi-round profile control of in-situ carbon dioxide generation in Bohai Oilfield, core flooding experiments were conducted to analyze reasons for poor performance of multi-round profile control of in-situ carbon dioxide generation. The effects of different plugging systems on control flooding were studied. The results show that the recovery rate of first-round flooding can be increased by 25.61% on the basis of water flooding, and the recovery rate of second-round flooding can be increased by 0.38% on the basis of first-round. Third round of flooding has no effect. 0.2 PV polymer injected before the third round of in-situ carbon dioxide generation shows no significant change in the effect of oil increase. 0.2 PV gel system injected before the third round of in-situ carbon dioxide generation will improve the recovery rate by 10.19% on the basis of second-round, which indicates that gel system can effectively block the hypertonic layer and turn the subsequent reagent solution into the low permeability layer. Thus mult-round profile control effect of in-situ carbon dioxide generation can be significantly improved. The results of the study provide a reference for multi-round profile control of in-situ carbon dioxide generation in strong heterogeneous reservoirs of Bohai Oilfield.

10.6056/dkyqt201901028