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answered Mar 14 by Normandy (21,040 points)

The lubricator valve for the subsea test tree is a surface-operated hydraulic valve that is run from one or two joints below the flow­head. It enables the top of the string to be used as a lubricator during wireline, slick­-line, or coiled tubing intervention operations, thereby reducing the amount of lubricator sections needed above the flowhead.

The lubricator valve is connected by a two- or three-line hose bundle to a surface-operating console. The third line may be used for injection of a hydrate inhibitor, such as glycol or metha­nol, just below the valve. In event of control line pressure failure, the valve will remain in the last position, open or closed, that it was placed in before the pressure loss occurred.

The lubricator valve is a pump-through valve and can be pressure tested from above (with hydraulic pressure maintained in the close line). When it is closed, the lubricator valve seals from either above or below to

  • withstand the well pressure when tools are introduced or removed from the upper section of the test string being used as a lubricator
  • test the flowhead and surface wireline or coiled tubing equipment.

Benefits of Lubricator Valve

  • Increases operational efficiency by testing pressure-control equipment without needing to pressure up the entire landing string
  • Enhances flexibility by reducing the amount of surface equipment necessary in operations that require long wireline, slick-line, or coiled tubing strings

Applications of Lubricator Valve

  • Subsea completions installation
  • Downhole testing and evaluation
  • Well cleanup
  • Well intervention and abandonment

Other Features of Lubricator Valve

  • Is tested and qualified to maximum pressure and temperature
  • Holds pressure from above or below
  • Enables pump-through to kill well by application of 1000-psi differential pressure from above
  • Includes option for chemical injection at the lubricator valve
  • Incorporates a fail-as-is design
  • Operates either as a lubricator valve or as a dual-valve system
  • Actuates as many times as necessary for well intervention operations
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