提高石油套管螺纹连接性能的三项技术和专利介绍

Introduction on Three Techniques/Patents for Improving Performance of Oil Casing Thread Connection

介绍了“圆螺纹连接不粘扣接箍”、“油田用高连接强度圆螺纹套管(HS-RTC)”、“高气密偏梯形螺纹套管(HT-BTC)”等技术和专利。圆螺纹连接不粘扣接箍专利是通过增大接箍螺纹起始牙的节径,采用一小段“引入螺纹”作过渡的接箍来消除粘扣现象的;HS-RTC专利是利用圆螺纹套管的黑皮螺纹参加连接来提高连接强度的;HT-BTC技术是将API偏梯形螺纹套管(BTC)的管端加工成圆弧形的轴向过盈金属密封面,缩短接箍长度,使接箍连接的两支套管的端面在油田紧扣后紧密封时,相互接触压紧,形成封闭的金属密封环,由此来提高密封性能。

Introduced here in the paper are three thread connection-related techniques / patents, namely, the ＂ Non-thread Sticking Coupling with Round Thread Connection＂, the ＂ Oil Field Service Casing with High Strength Round Thread Connection＂ （HS-RTC） and the ＂High Airtight Buttress Threaded Casing＂ （HT-BTC）. The patent of ＂Non-thread Sticking Coupling with Round Thread Connection＂ involves such a technique to eliminate thread sticking with bigger pitch circle of the initial threads of the coupling and a small transitional section of ＂lead-in threads＂. The patent of the HS-RTC is of a solution to enhance connection strength with the black threads of the round threaded casing. And the technique of the HT-BTC provides a solution to enhance the airtight performance of the API buttress threaded casing （BTC） by means of machining the casing end face into a curved axial shrink metal-tight surface and reducing the coupling length so as to ensure that when each two casings are coupled at site the end faces of them are strongly pressing against each other to form a metal seal ring.