复合月牙形磨损套管剩余强度研究

Study on Residual Strength of Composite Crescent Worn Casing

关于套管剩余强度的研究,主要集中于无磨损套管或者单月牙磨损套管,未充分研究复合月牙磨损形状对套管剩余强度的影响规律。为此,开展了单月牙磨损与双月牙磨损套管剩余强度的室内试验,建立了套管失效的判断准则,计算了不同缺陷形式下套管剩余强度。研究结果表明:磨损深度对于套管剩余强度的影响最敏感,磨损深度的增加使套管抗内压、抗外挤的强度均减小;次磨损槽对抗内压强度影响较小,对抗外挤强度影响明显。研究成果可为油气井作业优化与安全控制提供参考。

Previous studies on the casing residual strength mainly focus on unworn casings or single crescent worn casings,but the influence of composite crescent worn shape on the casing residual strength was not fully studied.Therefore,the laboratory tests of casing residual strength with single crescent wear and double crescent wear were carried out,the judgment criteria of casing failure were established,and the casing residual strength with different wear patterns was calculated.The results show that the wearing depth has the most influence on the casing residual strength,and the increased wearing depth reduces the casing strength against internal falling and external pressure.The secondary wear groove has little influence on the internal pressure strength,but it has obvious influence on the external falling strength.The study results provide reference for the operation optimization and safety control of oil and gas wells.