稠油油藏单水平井SAGD技术适用性分析及注采方案优化

Applicability analysis for single horizontal well SAGD in heavy oil reservoir and optimization of injection-production scheme

单水平井蒸汽辅助重力泄油(SAGD)技术可有效提高薄层稠油油藏的开发效果。利用数值模拟方法进行单水平井SAGD开发技术的适应性分析,基于储层开发经济极限指标形成储层适应性筛选原则,并以油汽比最高为目标进行注采参数优化。结果表明:油藏储层越厚、孔隙度、渗透率、含油饱和度越大,越有利于单水平井SAGD开发;其开发效果随储层原油黏度增加而下降,可以按原油黏度分类筛选适于单水平井SAGD开采的薄层油藏;开发方案采用注汽速度60 m^(3)/d递增并稳定在200 m^(3)/d,采注比1.15~1.20、水平井射孔段长度120 m、水平井斜倾角1.32°的单水平井,其SAGD开发效果较为合适。

The single horizontal well steam assisted gravity drainage(SAGD)technology can effectively improve the development effect of thin heavy oil reservoirs.The adaptability analysis of the single horizontal well SAGD development technology was carried out by the numerical simulation method.Based on the economic limit index of reservoir development,the principles of reservoir adaptive screening were formed,and the optimization of injection-production scheme was carried out with the goal of highest oil-steam ratio.The results indicate that the thicker the reservoir,the greater the porosity,permeability and oil saturation,the more conducive to the single horizontal well SAGD development.Its development effect decreases with the increase of the viscosity of the reservoir crude oil.According to the classification for the viscosity of the crude oil,the thin reservoir suitable for a single horizontal well SAGD exploitation is screened.The single horizontal well SAGD development effect is the best with the value decreasing of 60 m^(3)/d and value stabilizing of 200 m^(3)/d for the steam injection rate,the production-injection ratio being in the range of 1.15-1.20,the horizontal well perforation section length being 120 m,and the horizontal well inclination angle being 1.32°.