超稠油氮气泡沫凝胶调剖体系的研究与应用

Research and Application of Profile Control Technology with Nitrogen and Foam Gel for Super Heavy Oil

辽河兴隆台超稠油油藏具有压实弱、胶结疏松、大孔高渗等特点,原油黏度高、非均质严重、近井距设计、井间动用差异大,导致蒸汽吞吐过程中汽窜干扰突出,影响生产效果。通过室内高温实验,综合泡沫发泡剂、凝胶体系、驱油助排剂的各自优点,复配出氮气泡沫凝胶体系。与普通凝胶相比,氮气泡沫凝胶体系具有较高的热稳定性和剪切稳定性,具有高选择性、高封堵能力、低油层伤害的优势,具备可靠的应用基础和条件。该体系在高温状态下利用泡沫贾敏效应实现对油井的调剖,利用凝胶提高泡沫的稳定性。其中,泡沫能够扩大封堵范围,降低对油层的伤害;消泡后,氮气可起到增能作用,有效抑制汽窜,改善措施井生产效果。2010年以来,现场应用51井次,结果表明,该体系可有效封堵汽窜大孔道,减缓汽窜影响,调整蒸汽流向,改善吸汽剖面,大幅提升剩余稠油的开发水平。

Xinglongtai super heavy oil reservoirs in Liaohe have the characters of weak compaction,loose cementation,large porosity and high permeability and so on.High crude oil viscosity,serious heterogeneity,small well space and great differences among interwell production result in obvious steam channeling disturbance during huff and puff and production results will be influenced.Nitrogen and foam gel system is prepared based on the comprehensive considering on the advantages of foaming agent,gel system and oil displacement assistant agent through the indoor temperature experiment.Compared with common gel,this system has advantages of high stability at high temperature or under shearing,high selectivity,high sealing ability,less formation damage.It has the application foundation and conditions.This system may be applied for profile control in oil wells through Jamin action at high temperature and stability of the foam may be improved by the gel.That is to say,foam may enlarge the sealing range and make the damage less;after debubbleing,nitrogen may play the role of energization and effective inhibition on steam channeling,and the producing results of the improved wells may be better.Since 2010,a total of 51 well-times on-site application has been shown that big channel will be sealed effective and the steam channeling effect may be slowed down;flow direction of the steam may be adjusted and steam absorption profile may be improved.Finally,development level of remaining heavy oil may be enhanced substantially.