旋流式井下二次油水分离同井注采技术适用性分析

Analysis of the applicability of the same well injection and recovery technology for swirling downhole secondary oil-water separation

针对含水率已达99%、超过经济开采极限的采油井,为进一步降低地面产出液量,在旋流式井下一次油水分离同井注采技术基础上,通过采用井下水力旋流器串联的方式,将采出液在井下再浓缩,形成旋流式井下二次油水分离同井注采技术。室内实验表明,两个水力旋流器串联后,分流比在15%~45%时,最大分离效率达到98.5%。通过现场试验,验证了旋流式井下二次油水分离同井注采技术的可行性,可将地面日产液量降幅提高至85%以上,实现了因特高含水关停的井组再利用,提高了油井采收率,为特高含水油田后期经济、有效开发探索一种新的模式。

In view of the problem that the water content of oil production well has reached 99%and exceeded the economic exploitation limit,to further reduce the output liquid volume on the surface,based on the swirling downhole primary oil-water separation and the same well injection and recovery technology,the same well injection and recovery technology for swirling downhole secondary oil-water separation is formed through using downhole hydrocyclone tandem connection to re-consolidate the recovered liquid in the well.Indoor experiments have shown that after two hydrocyclones are connected in series,the maximum separation efficiency reaches 98.5%when the separation ratio is between 15%~45%.Through on-site experiments,the feasibility of the same well injection and recovery technology for swirling downhole secondary oil-water separation has been verified,which can reduce the daily liquid production on the surface by more than 85%,achieve the reuse of shut-down well groups due to high water content,improve the recovery rate of oil well,and explore a new mode for the later economic and effective development of ultra-high water content oilfields.