中国油气井压裂井口保护器技术现状

Technical Status of Wellhead Protector for Oil and Gas Well Fracturing Presently in China

油气井压裂井口保护器的作用是在油气井酸化、增产压裂过程中保护井口装置不被压裂液冲刷和腐蚀,避免为满足酸压而选用高级别的井口,从而节约成本。比较国内现有几类油气井压裂井口保护器的结构、工作原理和特点,结果表明现有井口保护器均采用胶筒组与管内表面密封,位置位于油管挂处,最终限制了保护器的通径尺寸,使大型压裂专用工具不能通过保护器;且常规井口保护器的最高压力级别大多在70MPa左右,低于页岩气压裂施工中的压力等级,不能用于非常规油气的增产作业。针对存在问题提出了改变常规井口保护器密封方式及位置的技术措施。建议中国应尽早着手研发适用于页岩气等非常规油气的专用压裂井口保护器。

The function of wellhead protector for oil and gas well fracturing is to protect wellhead device,prevent it from being washed and corroded in the process of acidizing and fracturing,avoid to choose the high pressure-rating wellhead that used to meet the need of acid fracturing,so as to save the cost. Compared with the structure,working principle and characteristics of current several kinds of wellhead protectors for oil and gas well fracturing in China,the results showed that existing wellhead protectors are sealed by rubber tube on inner surface of pipe,the position is located in the tubing hanger,which restricts the bore size of protector,so,the special tools for large scale fracturing can＇ t pass through the protector.Moreover,the maximum pressure level of conventional wellhead protector is only 70 MPa,and lower than the pressure level in the process of shale gas fracturing,preventing it from being used to the stimulation of unconventional oil and gas. In the paper,the technical measures to change the sealing method and position of conventional protectors are proposed,and suggested that China should be early developed the special wellhead protectors for unconventional oil and gas fracturing,e. g.shale gas.