利912块白云岩油藏酸压酸液体系试验研究

利津油田利912块白云岩储层属薄层裂缝型层状油藏,油藏埋藏深、压力高、非均质性强,针对这一特点,采用"稠化酸酸压+裂缝闭合酸化工艺"对其进行开发。通过盐酸酸化试验确定20%盐酸作为基础酸液,通过试验筛选1.5%的EL-10为缓蚀剂,2%的EL-4和KCY-03为黏土稳定剂,0.5%的EL-19为破乳剂,0.5%的EL-11为助排添加剂,5%的EL-22为稠化降阻剂。确定的降阻稠化酸和闭合酸在常温下和95℃下配伍性良好,表面张力和界面张力低、降阻性能良好、防膨效果明显,能够适应利912区块白云岩油藏的开发要求。

EXPERIMENTAL STUDY ON THE ACID FLUID SYSTEM USED IN THE DOLOMITE RESER VOIR OF NO.912 BLOCK OF LIJIN OILFIELD

The dolomite reservoir in No.912 Block of Lijin Oilfield is a thin-layer fractured reservoir with deep burial depth,high pressure and strong inhomogeneity.Gelled acid fracturing followed by closure fracture acidizing technology was applied to this reservoir.Through acidizing test of chlorhydric acid,chlorhydric acid(20% v/v) was chosen as base fluid,EL-10(1.5% v/v) was chosen as corrosion inhibitor,EL-4 and KCY-03(2% v/v) were chosen as clay stabilizer,EL-19(0.5% v/v) was chosen as demulsifying agent,EL-11(0.5%) was chosen as cleanup additive,EL-22(5% v/v) was chosen as gelling agent and friction reducer.The compatibleness of gelled acid and close acid was very good at atmospheric temperature and 95 C,surface tension and interfacial tension were low,friction reduction and clay stabilization were good which meet the requirements of No.912 Block reservoir development.