海上钻具破损现象研究

针对平湖油气田钻井中频繁发生的钻杆刺漏现象 ,组织了多学科、多专业的综合研究。从钻杆刺漏现象的大量试验研究得出结论 :(1 )钻杆刺漏的主要原因是钻井扭矩过大 ,造成钻杆基体薄弱处产生疲劳载荷下的微裂纹 ,钻杆内壁受高压钻井液冲蚀而刺漏 ;(2 )钻杆刺漏的次要原因是井眼中含有少量的H2 S气体 ,此气体伴随高压钻井液冲蚀钻杆内的疲劳微裂 ,从而加剧钻杆的刺漏腐蚀程度 ;(3)应针对平湖油气田地层中的特殊微量有害气体 ,研制有特殊内涂层的钻杆 ,以改善钻杆的抗腐蚀性能

Research on damage of drilling pipe in offshore oilfield

A lot of drill pipes have been damaged or corroded in PH oil and gas field in the offshore of China since 1997 during drilling. And it was called by engineers of rig site as cut through of pipe in drilling fluid. To solve this problem, a comprehensive research was made by means of simulation test and lab test. The result shows that, (1) excessive drilling torque causes the formation of tiny cracks in weak area of the drill pipe body, and the inner wall of the pipe is eroded and cut through in high pressure drilling fluid; (2) a little of H 2S in the well corrodes the drill pipe and accelerates cut through of pipe. Thereby drilling pipe with special inner coating should be developed according to the characteristics of the formation in PH oil and gas field to improve the pipe's corrosion resistance.