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Title: Pipe ram improvement facilitates hang off

Journal Article · · Oil Gas J.; (United States)
OSTI ID:5719447

Hard facing on the top surface of ram blowout preventors (BOPs) can prevent deformation when hanging off drill pipe. A new ram body features this hardfacing. This improvement is important to floating drilling because it transfers potential damage from critical pressure components to relatively inexpensive and less critical drill pipe upsets. National Association of Corrosion Engineers (NACE) specifications for H/sub 2/S resistance often mean that pipe rams do not have the hardness required to hang off long strings without deformation to the ram. Conventionally, the problem has been solved by welding a harder material to the portion of the ram on which the tool joint lands. This method, although widely used, can result in cracking in the inlaid area of the ram. In a typical sequence, weather requires a floating drilling rig to disconnect. The pipe rams are closed after the bit is pulled off bottom. The string is lowered until a tool joint is in the rams. The drillstring is backed off, leaving downhole string weight on the rams. Upper rams are shut, and upper marine riser package, riser, and drillstring are disconnected, freeing the vessel from the well. On reentry, the operator can find that the ram bodies are damaged or the inlay is broken. This can necessitate pulling the riser for BOP stack maintenance.

OSTI ID:
5719447
Journal Information:
Oil Gas J.; (United States), Vol. 84:22
Country of Publication:
United States
Language:
English