氮气泡沫开发稠油底水油藏的物质平衡方程

Material balance equations of heavy oil reservoir with bottom water exploited by injecting nitrogen foam

稠油底水油藏蒸汽吞吐过程中易形成底水在加热范围内的锥进,在底水锥进严重的生产井底部高压注入氮气泡沫,可以将水锥压回原始油水界面。将注氮气泡沫压水锥的过程看作气驱油、油驱泡沫和泡沫驱水3个过程,建立了多轮次蒸汽吞吐后注氮气泡沫控制稠油底水油藏底水锥进的物质平衡方程,得到了泡沫分离的氮气和表面活性剂溶液的启动油量、原油富集带厚度以及底水面深度的计算方法。对胜利油田某稠油底水油藏的一口生产井实施注氮气泡沫压水锥进行了计算,结果表明,对于600 m3/h的注氮气速度,注泡沫19 d可将水锥压回原始油水界面,最优的射孔高度距原始油水界面14.26 m。

Bottom water coning exists in steam heating area during the multiperiodic steam huff and puff in heavy oil reservoir with bottom water. Nitrogen foam injected into bottom of water coning well can push bottom water to original water-oil contact. The process of water coning control by injecting nitrogen foam was simplified as gas driving oil, oil driving foam and foam driving water. Material balance equations were obtained to study the water coning control technology in heavy oil reservoir with bottom water. The calculation methods of augment oil volume of injected nitrogen foam and released nitrogen, thickness of enriched oil zone and depth of bottom water were proposed. These equations were applied to a production well of heavy oil reservoir with bottom water in Shengli Oilfield. The results show that the water coning can be pushed to the original water-oil Contact at nitrogen injection rate of 600 m^3/h after injecting nitrogen foam 19 days, and the optimum wellbore penetration into a payzone is 14. 26 m above the original water-oil contact.