酸性气田钻具常见失效形式

近些年来,随着酸性气田的不断勘探开发,钻具失效事故时有发生,阻碍了天然气的安全高效开发。在全面分析了酸性气田开发中存在的各种腐蚀环境后,对酸性气田中普遍存在的氧腐蚀、二氧化碳腐蚀和硫化氢腐蚀三种腐蚀失效机理进行了分析;并通过具体的酸性气田开发中出现的钻具失效案例,分析了钻具在氧气、二氧化碳和硫化氢三种不同的酸性腐蚀环境下的裂纹萌生与扩展特点以及失效形式;最后提出了预防钻具腐蚀失效的措施,对预防和减少酸性气田开发中钻具失效事故的发生具有指导意义。

Common Failure Forms of Drilling Tools in Acid Gas Field

In recent years, with the exploration and development of acid gas field, drilling tools failure accidents have occurred occasionally, which hinders the safety and efficient development of natural gas. After a comprehensive analysis on the variety of corrosive environment in the acid gas field, the failure mechanism of oxygen corrosion, carbon dioxide corrosion and hydrogen sulfide corrosion to the drilling tools was analyzed. Through specific case of drilling tools failure in the acid gas field, the crack initiation and propagation characteristics and failure modes in oxygen, carbon dioxide and hydrogen sulfide corrosive environment were introduced. Finally measures and method to prevent drilling tools corrosion failure were proposed. It has important practical significance to guide the prevention and decrease drilling tools failure accidents in the acid gas field.