Casing gas seal screwed joint for shale gas well

The utility model discloses a casing gas seal screwed joint for a shale gas well, which adopts a small-negative-angle bearing surface, improves the tensile property of thread teeth, is suitable for lifting operation of a long-distance horizontal and large-dogleg-degree borehole casing in the tripping-in process of the shale gas well, and is suitable for the characteristic of deep burying of shalegas reservoirs in China. The thread form adopts a low positive angle guide surface, is easy for thread buckling and screwing, has the advantage of thread gluing resistance, also has the effect of increasing the compression load resistance of the thread, and is suitable for pressing operation in the tripping-in process of a shale gas well long-distance horizontal and large-dog-leg-degree borehole casing. 本实用新型公开了一种页岩气井用套管气密封螺纹接头，该接头采用了小负角度承载面，提高螺纹牙抗拉伸性能，适于页岩气井长距离水平及大狗腿度井眼套管下入过程上提操作，适于我国页岩气藏埋藏较深的特点；螺纹牙型采用了低正角度导向面，易于螺纹对扣、上扣，具有抗粘扣优点，同时兼顾了增加螺纹抗压缩载荷作用，适于页岩气井长距离水平及大狗腿度井眼套管下入过程下压操作。