CAJ | 학술논문

新版的 API 5C3-2008标准已经颁布实施，其附录中给出了新的套管挤毁强度计算公式。将其与 API 5C3-1994标准中套管挤毁强度计算公式（旧公式）进行了对比分析，并按新公式计算了油田常用套管的抗挤强度值。认为新公式建模更合理，计算结果更精确，且计算结果相对于旧公式的值发生了较大的变化。对于140钢级以下的套管，当套管径厚比大于20时，新公式计算值大于旧公式值；当径厚比小于20时，新公式值小于旧公式值。对140钢级以上的套管，这一变化的径厚比的界限值为22。基于对套管抗挤强度值的新认识，给出了套管柱设计时油田常用套管的合理抗挤安全系数建议值。
신판적 API 5C3-2008표준이경반포실시，기부록중급출료신적투관제훼강도계산공식。장기여 API 5C3-1994표준중투관제훼강도계산공식（구공식）진행료대비분석，병안신공식계산료유전상용투관적항제강도치。인위신공식건모경합리，계산결과경정학，차계산결과상대우구공식적치발생료교대적변화。대우140강급이하적투관，당투관경후비대우20시，신공식계산치대우구공식치；당경후비소우20시，신공식치소우구공식치。대140강급이상적투관，저일변화적경후비적계한치위22。기우대투관항제강도치적신인식，급출료투관주설계시유전상용투관적합리항제안전계수건의치。
Absttact:API 5C3-2008 standard has been promulgated and implemented.The new formula to calculate the casing collapse strength has been given in its appendix.In this paper,it is conducted that comparative analysis of formula to calculate the casing collapse strength in API 5C3-1994.It suggests that the new formula is more accurate,the model is more reasonable,because the effect of manufacturing factors and material properties on casing collapse strength is considered.The collapse strength of common oilfield casing is calculated according to the new formula.The value of new formula is very different from the results given in API 5C2-1999.The results show that:For casing steel grade below 140,the value of the casing collapse strength is greater than that of API 5C2 when the casing of diameter thickness ratio is greater than 20;It is less than that of API 5C2 when the diameter thickness ratio is less than 20.For casing steel grade over 140,the limit value of diameter thickness ratio is 22.So this paper gives reasonable collapse safety factor of common casing.