泡沫酸酸化技术在曙光油田的应用

Application of Foamed Acid Acidification Technology in Shuguang Oilfield

针对曙光油田超稠油油藏原油物性差、储层非均质性强、单层厚度薄、黏土矿物含量高、油层伤害类型复杂、采用常规酸化工艺效果有限等问题,使用泡沫酸化技术,可实现油层均匀处理,解除油层伤害。室内试验筛选出石油磺酸盐（AAS）作起泡剂,六磷酸钠作稳泡剂,确定了泡沫酸体系配方为：6%-15%HCl＋0.5%-3%HF＋2%-3%缓蚀剂＋0.5%AAS＋0.3%-0.5%六磷酸钠＋1%-3%黏土稳定剂,酸化体系对地层的配伍性好,缓蚀效果好。现场应用泡沫酸酸化技术,得出周期对比平均注汽压力降低了1.5 MPa,平均油汽比提高了0.2,采注平均比提高了0.606。

In view of the poor physical properties of the crude oil produced from the super viscous crude oil reservoir of Shuguang Oilfield,strong reservoir heterogeneity,thin monolayer thickness,high clay mineral content,complex types of reservoir damage, and limited effect achieved with conventional acidizing technology,foamed acid acidification technology was used to realize uniform treatment of reservoir and to eliminate reservoir damage. Petroleum sulfonate（ AAS） was chosen as the foaming agent and sodium hexametaphosphate was chosen as the foam stabilizer in laboratory test,and the optimum formulation of foamed acid system was identified： 6% to 15% HCl ＋ 0. 5% to 3% HF ＋ 2% to 3% corrosion inhibitor ＋ 0. 5%AAS ＋ 0. 3% to 0. 5% sodium hexametaphosphate ＋ 1% to 3% soil stabilizer. This foamed acid system is well compatible with the formation and has good corrosion inhibition effect. The field application of this foamed acid acidification technology has shown that the average steam injection pressure was reduced by 1. 5 MPa,the average oil-to-gas ratio was reduced by 0. 200,and the average production-to-injection ratio was increased by 0. 606 compared to previous production period.