摘要
高温深井套管受钻柱摩擦力、受拉或受压轴向应力、内外压差径向应力及周向应力影响,易造成套管损坏。从载荷计算、控制方程、边界条件及求解方法等方面入手,得到套管最大允许掏空深度、最低允许替液密度、最大允许抗内压和套管磨损后的强度校核计算方法。结果表明,当套管掏空负压时,在井筒液体密度小于套管外泥浆密度情况下,危险点处于套管鞋处;当井筒液体密度大于或等于套管外泥浆密度时,危险点处于套管掏空深度点及以下;当套管被替成最低密度时,最先损坏的危险点为套管鞋处;当套管性能一致时,井口位置抗内压最薄弱。大港油田30口试油井对套管强度进行了校核,现场未发生因套管强度问题导致的试油安全事故。该技术对同类高温深井试油套管强度校核具有参考价值。
The casing in the high temperature deep well is affected by the friction of the drill string,the axial stress of tension or compression,the radial stress of internal and external pressure difference and the circumferential stress,and is easy to be damaged.This paper introduces the methods for calculating the maximum allowable hollowing depth,the minimum allowable liquid density,the maximum allowable internal pressure resistance and the strength check of casing abrasion from aspect of load calculation,governing equations,boundary conditions and solving methods.The results show that under the negative pressure in the casing,the dangerous point is at the casing shoe when the wellbore liquid density is less than the casing mud density.The dangerous point is at the point and below of the casing hollowing point when the wellbore liquid density is greater than or equal to the casing outer mud density.The most dangerous point of damage is the casing shoe when the casing is replaced by the lowest density.The wellhead position is the weakest when the casing performance is consistent.The casing strength was checked by 30 oil wells in Dagang Oilfield.There was no oil safety accident caused by casing strength problems.This technology can provide support for the strength check of similar high temperature deep well testing casings.
作者
郭秀庭
任世举
彭雪梅
刘光普
GUO Xiuting;REN Shiju;PENG Xuemei;LIU Guangpu(Petroleum Engineering Research Institute,PetroChina Dagang Oilfield Company,Tianjin 300280,China;Exploration Department,PetroChina Dagang Oilfield Company,Tianjin 300280,China;Oilfield production division of CNOOC Oilfield Services Co.,Ltd,Tianjin 300459,China)
出处
《油气井测试》
2019年第6期38-43,共6页
Well Testing
基金
中国石油勘探与生产分公司科研项目“大港油田歧口斜坡带与潜山试油配套技术研究”(kt2017-15-03-1)
关键词
大港油田
深井
高温井
试油
掏空深度
泥浆密度
套管强度
计算方法
Dagang Oilfield
deep well
high temperature well
testing oil
hollowing depth
mud density
casing strength
calculation method
