摘要
为解决渤海油田多轮次层内生成CO_2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CO_2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CO_2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CO_2调驱溶液转向低渗层,从而显著改善多轮次层内生成CO_2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CO_2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 multi-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.
作者
杨寨
郑玉飞
YANG Zhai;ZHENG Yufei(Liaodong Operation Company,Tianjin Branch of CNOOC Ltd.,Tianjin 300452,China;Production Department of China Oilfield Services Limited,Tanggu 300459,China)
出处
《断块油气田》
CAS
CSCD
北大核心
2019年第1期123-126,共4页
Fault-Block Oil & Gas Field
基金
国家科技重大专项"大型油气田及煤层气开发"(2016ZX05058)
