Phuel Risers (or Lubricators) are pressure containing tubular sections with threaded or flanged connectors used in wireline operations.
They allow the wireline tool string to be raised above the wellhead valve, permitting entry and exit from the well bore. For electric line operations the risers normally have the same internal diameter; for slickline operations, different bore sizes can be used, smallest bore at the top.
Risers of up to one meter can be manufactured from a single piece of material (Integral
design). Longer lengths (Multi-Piece design) are normally three pieces threaded together.
In the Multi-Piece design, sealing is achieved via metal-to-metal ACME sealing connections backed by O-rings.
End connections are either Quick Union or Flanged to suit the rest of the Stack-Up and
pressure requirements .
The Multi-Piece design can be used up to 10,000 PSI, the Integral design can be used up to 15,000 PSI. (Note: for the shorter Riser lengths its normally more cost effective to choose the Integral design)