S135钻杆钢在钻井液中的氧腐蚀行为

基于系统的理论分析和现场腐蚀产物的XRD分析,揭示了S135钻杆钢在3%NaCl溶液中的氧腐蚀机理。为研究腐蚀因素与腐蚀速率的关系,通过室内高压釜动态模拟实验,分别研究了钻井液中含氧量、钻井液温度、钻井液流速和钻井液盐浓度对S135钻杆钢的氧腐蚀速率影响规律。实验研究结果表明(1)3%NaCl盐水钻井液对S135钻杆钢的腐蚀主要是氧去极化作用所致;(2)钻井液含氧量和钻井液流速的增加会加快钻杆钢的氧腐蚀速率,而钻井液温度和含盐量对钻杆钢的氧腐蚀速率具有双重作用。

The Oxygen corrosion behavior of S 135 drill pipe steel in drill fluid

On the basis of the systematic theoretical analysis and the X-ray diffraction analysis of corrosion products, the oxygen corrosion mechanism of drill pipe steels in 3%NaCl solution was studied. Through the dynamic simulation test of the indoor autoclave, the law of the influence of oxygen content, drill fluid temperature, drill fluid flow velocity and the salt concentration of the drill fluid on the oxygen corrosion rate of the S135 drill pipe steel was studied separately in order to investigate the relationship between corrosion factors and corrosion rate. The results indicated: 1) the corrosion of 3%NaCl saline drill fluid on the S135 drill pipe steel is mainly due to the oxygen depolarization effect; 2) the increase of the oxygen content and flow rate of the drill fluid would promote oxygen corrosion rate of the drill pipe steel, and the temperature and salt content of drill fluid act dually on the oxygen corrosion rate of the drill pipe steel.