合理选用管柱.井眼作业受力模型及综合考虑摩阻因素是实现连续管作业受力准确计算的前提与基础。根据超深井连续管作业特点,考虑温度、井内介质流动阻力等因素影响,建立了连续管作业综合受力模型,用开发的软件实现了连续管作业过程中的受力、变形情况及井口注入头所需注入力的实时变化模拟。模拟结果表明,连续管上提作业安全余量较下放作业安全余量小,下放作业连续管弯曲情况更为严重,螺旋屈曲井段更长,造成附加接触摩阻占总摩阻的比例较大;对于井内压力较大的情况,建议下放作业时适当增大连续管填充压力,上提作业时适当减小连续管填充压力。
Proper selection of string-hole operation force model and comprehensive consideration of friction fac- tor are the precondition and basis for achieving the accurate calculation of coiled tubing (CT) operation force. According to the CT operating characteristic in superdeep wells, the comprehensive force model of CT opera- tion was established considering such factors as temperature and downhole medium flow resistance. The developed software was used to achieve the real-time change simulation of force, deformation and injection force required by wellhead injector head in the process of CT operation. The simulation shows that the safety margin of CT lifting oper- ation is smaller than that of its running operation. The bending of CT in running is more serious. The spiral buckling is longer. The proportion of added contact friction in the overall friction is larger. As far as relatively large downhole pressure is concerned, it is suggested that CT filling pressure should be increased properly in running operation while the pressure should be decreased properly in lifting operation.