Apparatus for treating or completing wells

摘要

A method of and apparatus for treating or completing wells to provide surface controlled subsurface safety systems in the wells, whether at the time of original completion or when the well is reworked or reequipped. A method and apparatus is provided for installing receptacles at the upper ends of one or more lower well flow conductors left in place in the well below the surface for receiving the lower ends of corresponding upper flow conductor sections having surface controlled subsurface safety valves connected therein for controlling undesired flow from the well through said lower flow conductors in the event of an emergency, disaster or accident damaging the surface flow controlling system or threatening the integrity thereof. A hanger or packer may be installed in the well casing below the surface for supporting the upper ends of the lower flow conductor or conductors therebelow and providing means for connecting receptacles at the upper ends of said lower flow conductors above such hanger or packer. The upper flow conductors having the flow controlling safety valves mounted therein may then be installed in the well in flow communication with the receptacles and the tubing strings or flow conductors therebelow. The upper flow conductor sections may have concentric or laterally offset parallel flow control fluid conduits communicating therewith for controlling actuation of the safety valves from the surface of the well. Also, conductor line means is provided for conducting fluids from above the hanger or packer at the upper end of the lower flow conductor to the annulus in the well casing therebelow for gas lift or for injection into the well producing formation, as desired. Check valve means is provided for controlling back-flow through such conductor means from below the hanger or packer to the annulus in the well casing thereabove.