镇北油田长8油层有机膦酸酸液增注体系研制及应用

酸化技术是储层改造最为常用的技术之一。根据镇北油田长8层的储层物性特征,研制并优化适合该储层的酸化增注体系。研究表明,有机膦酸酸液体系主要成分为有机膦酸和含氟化合物,通过酸液添加剂的筛选与研究,确定了酸液体系配方。主体酸配方:2%NH4F+10.0%有机膦酸+0.5%柠檬酸+1.5%乙酸+0.5%助排剂TF-1+2%缓蚀剂SJC;前置酸配方:12%HCl+3%乙酸+0.5%柠檬酸+1%缓蚀剂SJC+2%防膨剂PDMD。岩心伤害试验结果表明有机膦酸体系对镇北油田长8层岩心的渗透率显著提高。2014年9月至12月,应用有机膦酸酸液分别对镇北长8层镇2x井、镇3x井和镇9x井进行现场试验,累计增注2 219 m3,平均降压5.77 MPa。

Development and Applications of Organic Phosphoric Acid Augmented Injection Agent for Chang 8 Reservoir in Zhenbei Oilfield

Acidizing technology was one of the most commonly used technology for reservoir reconstruction.Poor original property of Chang 8 reservoir Zhenbei oilfield was one of the main influential factors of the reservoir development.Acid system was researched and optimizated for Chang 8 reservoir in Zhen Bei Oilfield.The study showed that the main components of the organic acid liquid system were organic phosphorus acid and fluorine containing compounds.Through the selection and study of acid additives, the formula of acid solution was determined.Main acid formula was 2%NH4F+10.0%organic phosphoric acid+0.5%citric acid+1.5%acetic acid +0.5%auxiliary drainage agent TF-1+2%corrosion inhibitor SJC.Pretreated acid formula was 12%HCl+3%acetic acid+0.5%citric acid+1%corrosion inhibitor SJC.The results of core damage experiment showed that the system of organic phosphate significantly increased the permeability of Chang 8 reservoir Zhenbei oilfield.From September to December in 2014,organic phosphonic acid was applied in Zhen2x well, Zhen 3x wells and Zhen 9x well.The injection rate increased 2219m₃, while injection pressure drop about 5.77MPa.