| 摘要 |
Installed in the tubing string portion of an offshore well rig are a vertically spaced pair of tubular well line protective devices. The upper device extends vertically through the openings in the rig floor and the rotary table thereon, and the lower device is positioned between a pair of sealing rams within an open upper end portion of the riser through which the tubing downwardly extends. Each protective device has a main body portion which is radially enlarged relative to the balance of the tubing string, and a removable side insert portion. Well lines, such as control, chemical and balancing lines, are extended through axial openings combinatively defined by each body and associated insert, with the insert shielding the lines from damage at the protective device location. The removable insert is illustrated in an all metal construction, used in the upper device, and an all elastomeric material construction or an elastomer-faced metal construction used in the lower device. The lower protective device is positioned between a pair of sealing rams. When the sealing rams close, the elastomeric portion of the insert portion of the lower device protects its associated well line portions from damage, and automatically creates seals around them, to block off the tubing/riser annulus and prevent leaking gas flow upwardly therethrough past the closed sealing rams. A bypass pipe structure disposed below the sealing rams diverts gas leakage outwardly past the rig when the rams are closed.
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