摘要 |
<p>A swivel device for use with a casing circulator in the exploitation of hydrocarbon reserves comprises an elongate housing (1) attachable at its upper end to a rigid portion on a derrick (not shown), and an elongate swivel means (8) having an upper end (4) rotatably mounted in the elongate housing (1) so as to provide precessional and pendular freedom to the lower end of said elongate swivel means, wherein said elongate swivel means is attachable at its lower end (2) to a casing circulator.</p> |