胜科1井钻具腐蚀防护技术研究与应用

Drilling Tools Anti-corrosion Technology for Well Shengke-1.

针对胜科1井三开钻遇的多套盐膏层、盐岩层、软泥岩与膏泥岩互层,以盐水对钻具钢材的腐蚀规律研究为基础,探讨了钻具腐蚀的影响因素,在优选出的钻井液配方基础上进行了不同缓蚀剂的配伍性试验,采用欠饱和复合盐水防腐钻井液,在Cl-含量大于16×104mg/L,温度达到140℃情况下,有效地解决了钻具防腐问题。现场应用表明,欠饱和复合盐水防腐钻井液不仅流变性能满足了钻井需要,而且对钻具腐蚀小,平均腐蚀速率均小于0.05 mm/a。

Severe drilling tools corrosion was experienced in the third interval of well Shengke-1 penetrated multiple salt and gypsum zones. An under-saturated salt drilling fluid was designed based on the laboratory studies on the corrosion behavior of salt water to steel. The corrosion of the under-saturated salt drilling fluid was greatly reduced because of its corrosion inhibition performance. Drilling tools corrosion was mitigated at chloride concentration greater than 16×104 mg/L and temperatures 140 ℃. The average rate of corrosion in field use was less than 0.05 mm/a.