Apparatus and method for locking open a flow control device

A safety valve for use in an oilfield tubular, the safety valve comprising:

• a housing having a longitudinal bore extending therethrough;
• a flapper valve member mounted in said housing and being hingeably movable relative to said longitudinal bore, said flapper valve member having an open position allowing fluid flow through said longitudinal bore and a closed position disallowing fluid flow through said longitudinal bore;
• and
• a rotatable lock-open sleeve disposed in said housing, said rotatable lock-open sleeve being movable in a generally circular path at least partially around the circumference of said longitudinal bore and adjacent to said flapper valve member, said rotatable lock-open sleeve being capable of holding said flapper valve member in its open position.

A subsurface safety valve with lock-open capability and useful in an oilfield tubular, the subsurface safety valve comprising:

• a housing having a longitudinal bore extending therethrough;
• valve closure means mounted in said housing for allowing and disallowing fluid flow through said longitudinal bore, said valve closure means having an open position capable of allowing fluid flow through the longitudinal bore and a closed position capable of at least partially blocking fluid flow through the longitudinal bore;
• and
• lock-open means for securing said valve closure means in said open position, said lock-open means being permanently disposed in said housing and movable in a generally circular path within said longitudinal bore.

A method of securing a shiftable valve member in an open position with the use of a locking sleeve, the shiftable valve member and locking sleeve being mounted in a housing having a longitudinal bore extending therethrough, the shiftable valve member being moveable between at least one open and at least one closed position relative to the bore, the locking sleeve being rotatable at least partially around the circumference of the bore from at least a first position to at least a second position, the shiftable valve member being retained in an open position when the locking sleeve is in the second position, the method comprising:

• moving the locking sleeve in a generally circular path from its first position in the direction of its second position;
• moving the shiftable valve member into an open position;
• moving the locking sleeve in a generally circular path into its second position;
• and
• securing the locking sleeve in its second position, thereby securing the valve member in its open position.