【摘要】 在石油和天然气行业中,油管、套管是油气井生产中重要的设施,准确地预测油管、套管抗挤强度能够防止或减少油管、套管失效事故的发生。针对API5C3计算精度偏低、对抗挤强度影响因素考虑不全面等问题,API/ISO工作组修订了现行API5C3标准,给出了含制造缺陷(椭圆度、壁厚不均度、残余应力、制造微裂纹等)的抗挤新模型,从而大大提高了套管强度计算的科学性。研究中发现,ISO抗挤新模型并不适合所有尺寸套管强度的计算,当前研究的成果与实际情况存在一定差异,这并非是ISO工作组要研究、修订API5C3的初衷。因此,建议后续研究者对ISO新模型进行必要的修正或改进,给出更可靠合理的计算模型。这要比单一用API5C3设计油管、套管强度更合理,既避免了材料的浪费又能保证材料的安全可靠性。更多还原

【Abstract】 Casings and tubings are widely used as protective conduits during all phases of drilling operations and productions in the oil and gas industry.Therefore,an accurate prediction of the collapse resistance strength is a very important consideration in the casing design to guard against failure accidents.The influence of manufacturing technology and imperfections on casing collapse strength have not been considered in the API 5C3 standard,while the collapse strength of current casings cannot be predicted accurately by the API 5C3 standard due to its low calculation accuracy.In such cases,the joint API/ISO Collapse Sub-Team has proposed the current API 5C3 standard and presented the new collapse strength model with manufacturing imperfections,such as ovality,eccentricity,residual stress,etc.,which upgrades the casing strength calculation accuracy and benefits much more for casing strength design.The study on the ISO collapse resistance new model has found that it cannot be used to calculate the collapse resistance strength of pipes with all sizes,and the current study results are greatly different from actual practices,which is not the ultimate goal for the ISO group to propose the API 5C3 standard.So,it is necessary that successive researchers should correct or develop a new ISO collapse resistance model,and present much more reliable and reasonable calculation model.This would benefit much more for in tubing and casing strength design than just using the API 5C3 standard,because it can not only avoid the material loss but also guarantee the safety and reliability of tubing and casing material;moreover,it can provide important reference for the engineers to optimize the strength design and improve the quality in the manufacture of tubings and casings.更多还原