保护碳酸盐储层的酸化完井液体系研究

Acidic Completion Fluid for Protection of Carbonate Reservoir

杨培龙 刘卫红 李 强 林 枫 程 爽

YANG Peilong LIU Weihong LI Qiang LIN Feng CHENG Shuang

针对伊拉克 Missan油田碳酸盐储层的特点， 以腐蚀性较弱的 HTG固体酸为主剂， 采用 NaCl、 HCOONa复合盐水调节密度并加入一定量缓蚀剂制备了一种保护碳酸盐储层的酸化完井液体系： 25% NaCl+ 10%HCOONa+ 3%HTG 固体酸+ 3% JCI缓蚀剂， 考察了该完井液对钻开液泥饼的冲洗能力、 破胶能力， 研究了完井液与钻开液滤液的配伍性以及完井液对储层的保护作用。结果表明， 该酸化完井液体系腐蚀性较小， 能够有效地清除钻开液形成的泥饼， 在无完井破胶处理的条件下能将泥饼的残渣全部清除； 钻开液污染后的岩心经该完井液体系处理后的渗透率恢复率可达 95%以上， 显示该完井液具有较好的储层保护作用。图 1表3参 10

According to the characteristics of carbonate reservoir of Iraqi Missan oilfields，an acidic completion fluid for protection of carbonate reservoir was prepared using a weak corrosion solid acid HTG as main agent，in which NaCl combined with HCOONa brine was selected to adjust the density of the completion fluid and a corrosion inhibitor JCI was added to control the corrosion of pipe string. The formula of the completion fluid was as follows：25% NaCl + 10% HCOONa + 3% HTG solid acid + 3% JCI corrosion inhibitor. The flushing ability of completion fluid to mud cake formed by drill-in fluid，gel breaking ability，compatibility of completion fluid with the filtrate of drill-in fluid，and the reservoir protection effect of the completion fluid were investigated. The results showed that the corrosivity of the completion fulid was lower，and the mud cake formed by the drill-in fluids could be removed effectively by the completion fluid and the residues of the mud cake could be cleaned up without gel breaking procedure. The permeability recovery of the core，which was polluted by drill-in fluid and then treated by completion fluid，reached over 95%，which indicated that the ompletion fluid had good effects of reservoir protection.

10.19346./j.cnki.1000-4092.2017.01.005