Despite various types and shapes, the design of premium connections for casing and tubing in different countries and companies is basically the same, mainly in order to improve the connection strength and sealing performance of tubing and casing.
Generally speaking, most special tubing connections are divided into three parts: connection threads, torsion shoulder and sealing face.
API trapezoidal threads are used in most connection threads of premium connection well tubing and casing to improve the interchangeability of threaded screw-in parts. Only a few premium connection tubing and casing adopt different geometric shapes, such as wedge of Hydril Series 500 series.
However, with the continuous development of drilling technology and pipe processing technology, the premium connection with the threaded teeth has a gradually expanding trend and a better development prospects.
