氯化钾钻井液缓蚀剂的研究

摘要

Drilling fluid additives have very complex composition which will cause corrosion to downhole drilling assembly,or even cause the drilling assembly to become unusable.To resolve this problem,corrosion inhibitors for use in KC1 drilling fluids have been selected through weight loss method,electrochemistry experiment and SEM,and the mechanisms of corrosion caused by KC1 drilling fluids have been studied.The best corrosion inhibition results were obtained with this drilling fluid composition:0.7％ silicon compound + 0.7％ diethylenetriamine + 0.1％ triethylenetetramine,the rate of corrosion inhibition was 90.36％.Electrochemistry and SEM tests showed that the corrosion inhibitor selected for use in KC1 drilling fluid had good corrosion inhibitive capacity and application prospect.%钻井液添加剂的成分比较复杂,会对井下钻具钢造成不可估计的腐蚀,甚至使钻具钢因腐蚀而报废.针对这一问题,笔者主要通过失重法、电化学实验及电镱扫描等途径,对氯化钾钻井液体系中缓蚀剂进行筛选,并对其腐蚀机理进行了研究.研究结果表明,0.7％含硅化合物+0.7％二乙烯三胺+0.1％三乙烯四胺复配时,缓蚀效果最好,缓蚀率达到90.36％;电化学实验和电镜扫描实验表明,该复配缓蚀剂产生的腐蚀电流较小,具有降低点蚀敏感性,抑制点蚀发生的效果.研究结果表明,该缓蚀剂可用于钾盐钻井液中钻具钢的防腐.