煤层气带压修井用气胎式环形防喷器设计

摘要

In order to meet the demand of rapid workover under pressure of coal bed methane (CBM) wells,and solve the problem that the rubber core of the original blowout preventer needs to be changed frequently because of serious wear,a air forced annular blowout preventer was designed.This blowout preventer utilizes the principle of air compression to realize the rapid passage of the tubing collar,its shell and rubber core are connected by the spline to facilitate the replacement of the rubber core.The sealing properties of the key component of rubber core were analyzed by ANSYS,the relationship between the contact pressure and the control pressure was obtained.The damage cause and the failure form of the rubber core were analyzed.The results show that,with the increasing of control pressure,the sealing pressure of the air forced annular blowout preventer is increases gradually,and the sealing pressure stabilizes at around 7 MPa when the control pressure is 4 MPa,which meets the sealing requirements in the workover.The pressure in the upper part of the rubber core is the most intensive and prone to cause overflow phenomenon,the curing of this part should be strengthened.%为了满足煤层气带压修并快速作业的要求,解决原有环形防喷器胶芯磨损严重,需要频繁更换的问题,设计一种气胎式环形防喷器.该防喷器利用空气压缩原理,实现了油管接箍的快速通过;壳体和胶芯采用顶丝和花键连接,方便胶芯更换.采用有限元分析方法对该环形防喷器的关键部件胶芯的密封性能进行分析,得到胶芯密封压力随控制压力的变化规律,分析胶芯破坏的原因和破坏形式.结果表明:随着控制压力的增加,气胎式环形防喷器的密封压力逐渐增加,当控制核动力为4 MPa时密封压力稳定在7 MPa左右,满足作业中的密封要求;胶芯的中上部位置压力最密集,容易出现溢流现象,应加强该部位的硫化.