Downhole tool for opening a travelling valve assembly of a reciprocating downhole pump

A downhole tool for opening a travelling valve assembly of a downhole pump, the tool and travelling valve assembly being disposed within a pump barrel, and the travelling valve comprising a valve member in a travelling valve housing, the valve member movable between an open position and a closed position, the tool comprising:

• (a) a substantially cylindrical housing, wherein the housing comprises an outer surface and defines:
• (i) an axial bore extending from a bottom opening for fluid communication with the pump barrel;
• (ii) at least one radial port for fluid communication between the axial bore and the pump barrel;
• (iii) for each of the at least one radial port, a channel formed in the outer surface of the housing for fluid communication between the at least one radial port and the travelling valve assembly;
• and
• (b) a piston slidably disposed within the axial bore and occluding the axial bore above the at least one radial port, wherein the piston is responsive to an upward pressure exerted by a production fluid below the piston to slide upwardly within the axial bore from a retracted position to an extended position in which the piston engages the valve member in the travelling valve housing to move the valve member to the open position.