多元复合酸酸化工艺的应用

卫城油田是典型的高压、低渗断块砂岩油藏,历年来酸化效果较差。从卫城油田的油藏物性等方面出发,分析了制约其酸化效果的因素:酸渣的影响、铁离子二次沉淀的影响,残酸返排的影响。针对这些问题,研究应用了多元复合酸酸化工艺技术,该工艺采用了独特的挤酸排酸一体化管柱。室内试验表明:该酸液具有缓速性能好、能有效防止铁离子二次沉淀、有效防止酸渣生成、与地层水配伍性好、防膨能力强、排残酸迅速等特点。现场应用高压注水井7口,平均降低注水压力12.8MPa,累计增加注水量27652m3,取得了较好的降压、增注效果。

APPLICATION OF POLYATOMIC-RECOMBINATION ACID TECHNOLOGY

Weicheng Oilfield is a typical rock sandstone oil reservoir.The result of acidizing is comparatively poor in recent years.Based on physical phenomenon of Weicheng Oilfield reservoir,influence factors of acidizing:influence of acid sludge,secondary precipitation of iron ion and influence of acid liquid discharged,were analyzed.Aimed at these problems,polyatomic recombination acid was brought under research and application.Negative pressure extrusion acid and discharged acid integrated pipe string were used of this technology.This acid liquid having distinguishing feature as:ability to prevent secondary precipitation of iron ion effectively,ability to prevent acid sludge coming into being effectively,fine compatibility with formation water and fine ability to antiswelling.All these were proved in the lab.This technology was used in seven high pressure water wells and injection pressure decreases 12 8 MPa on average,cumulative increase water injected 27652m 3.Comparatively fine result of decreasing injection pressure and increasing water injected are obtained.