Gas lift valve having ratcheting orifice

A gas lift valve comprising:

• a housing defining an internal passage having a first port, a second port, and a third port, the first port exposed to an annulus pressure, the second port exposed to a tubing pressure, the third port being configured to at least communicate outside the housing, a portion of the internal passage defining a ratchet profile disposed thereabout;
• a piston sealed in the internal passage, the piston being movable in first and second axial directions with axial movement between first and second positions in the internal passage at least in response to a pressure differential between the first and second ports, the piston in the first position permitting communication between the first port and the third port, the piston in the second position restricting communication between the first port and the third port;
• and
• an indexing assembly disposed on the piston and comprising:
• a first ring disposed on the piston and having a first cam surface;
• a second ring disposed on the piston and having a second cam surface, the first and second cam surfaces having an offset from one another;
• an inner collar attached to the piston, the inner collar having an intermediate outer surface and having first and second intermediate cam surfaces, the first and second intermediate cam surfaces spaced between the first and second rings, the intermediate outer surface having outer longitudinal ridges disposed therebout;
• and
• an outer collar disposed about the inner collar and being expandable and contractable, the outer collar having an inner surface and an outer surface, the inner surface having inner longitudinal ridges disposed thereabout, the outer surface having an outer circumferential ratchet disposed thereabout,
• the first and second intermediate cam surfaces being configured to alternately engage the first and second cam surfaces,
• the offset of the first and second cam surfaces being configured to rotate the piston and the inner collar in incremental rotations in response to the first and second intermediate cam surfaces alternatingly engaged with the first and second cam surfaces,
• the incremental rotations of the inner collar being configured to alternatingly expand and contract the outer collar in an expanded state and a contracted state in response to the outer longitudinal ridges of the inner collar engaged and disengaged with the inner longitudinal ridges of the outer collar,
• the outer circumferential ratchet on the outer collar in the expanded state on the piston in the second position being configured to engage with the ratchet profile and being configured to prevent the axial movement of the piston in the first axial direction,
• the outer circumferential ratchet on the outer collar in the contracted state on the piston in the second position being configured to disengage with the ratchet profile and being configured to allow the axial movement of the piston in the first axial direction.

A method used for a gas lift completion in a wellbore, the method comprising:

• at least controlling fluid communication through a gas lift valve by:
• producing pressure differentials in an internal passage of the gas lift valve between an annulus pressure of the wellbore and a tubing pressure of the gas lift completion;
• and
• alternatingly moving a pressure-sensitive piston in first and second axial directions with axial movement between first and second positions in the gas lift valve in response to the pressure differentials;
• holding and releasing the pressure-sensitive piston at least in the second position by:
• rotatably indexing an indexing assembly in incremental rotations in response to the axial movement of the pressure-sensitive piston in the second position alternatingly in the first and second axial directions;
• and
• alternatingly expanding and contracting an outer circumferential ratchet in expanded and contracted states in response to the incremental rotations of the indexing assembly on the pressure-sensitive piston in the second position;
• and
• alternatingly preventing and allowing the axial movement of the pressure-sensitive piston in the first axial direction from the second position by alternatingly engaging and disengaging the outer circumferential ratchet in response to the expanded and contracted states with a ratchet profile defined in the internal passage.