海上稠油油藏蒸汽吞吐周期注汽量优化研究

Cyclic steam injection volume optimization of steam huff and puff in offshore heavy oil reservoirs

海上稠油油田蒸汽吞吐开发与陆上油田相比更为复杂,周期注汽量的合理选择已越来越受到重视。以渤海油田某稠油油藏为研究对象,根据海上油田特点建立概念模型,运用数值模拟方法对蒸汽吞吐周期注汽量进行优化研究,首先设计7种方案对各周期注汽段塞进行了定性研究;在此基础上,针对开发效果最好的注汽段塞方案又设计12种方案进行定量细化研究。结果表明,研究区蒸汽吞吐开发时各周期注汽量应随着周期数的增加而增加,且各周期注汽量递增率均为20%时开发效果最好。M油藏实际区块数值模拟结果表明,吞吐10周期后,蒸汽吞吐周期注汽量最优方案比各周期注汽量相同的注汽方式的累积产油量提高4.58×104m3,采出程度提高0.53%。

Due to the big discrepancy between onshore and offshore oilfields, the development of cyclic steam stimulation in offshore oilfields appears to be more complicated. And a reasonable choice of steam injection volume has attracted increasingly wide attention.Based on the heavy oil reservoir in Bohai oilfield, a numerical simulation model of cyclic steam stimulation was built based on the characteristics of offshore oilfields. The numerical simulation was used to optimize the cyclic steam injection volume. First, seven kinds of programs were designed on steam injection slug size for qualitative research. For the best result, twelve kinds of programs were designed for quantitative research. The results show cycle steam injection volume should be increased with increasing number of cycles,and the increasing rate of each cycle steam injection is 20% with best results. The results can provide theoretical guidance for cyclic steam injection volume optimization of steam huff and puff in offshore oilfields.