海上蒸汽驱井筒长效安全控制工具研制及应用

针对海上稠油井蒸汽驱工艺的注热时间长、井下高低温交变工况的特点,进行注热管柱设计及配套井下工具的技术攻关,达到蒸汽驱井筒长效安全控制的目的。蒸汽驱井下安全控制管柱采用了以高温环空安全封隔器、高温井下安全阀为核心,辅以高温排气阀、热敏封隔器的设计,能够实现高效隔热、环空充氮及洗压井、地面控制应急关断等功能。配套井下工具方面,通过全金属密封结构设计,实现了高温环空安全封隔器、高温井下安全阀通用密封设计,提高了工具的可靠性。现场应用表明,蒸汽驱井下安全控制管柱设计合理,地面和井下工具工作正常。为海上蒸汽驱的安全高效实施提供了有力的保障。

Development and Application of Long Term Wellbore Safety Control Tools for Offshore Steam Drive

According to the characteristics of long heat injection time and downhole high and low-temperature alternating working conditions of steam drive in offshore heavy oil wells,the technical research of heat injection string design and downhole tools were carried out to achieve the purpose of long-term safety control of steam drive wellbore.The steam drive downhole safety control string adopts the design of a high-temperature annulus safety packer and high-temperature subsurface safety valve as the core,supplemented by a high-temperature exhaust valve and thermal packer,which can realize the functions of high-efficiency heat insulation,annulus nitrogen filling,well flushing and killing,ground control emergency shutdown and so on.In terms of supporting downhole tools,through the design of an all-metal sealing structure,the general sealing design of a high-temperature annular safety packer and high-temperature downhole safety valve was realized,which improved the reliability of tools.The field application shows that the design of steam drive downhole safety control string is reasonable and the surface and downhole tools work normally.It provides a strong guarantee for the safe and efficient implementation of offshore steam drive.