Abstract: A slip spool includes radially disposed actuators for radially moving slip blocks between a loose encirclement position in which they surround the tubing string and a cached position in which the slip blocks clear an axial passage of the slip spool. The slip spool further includes axially disposed actuators for axially displacing the slip blocks between the loose encirclement position and an engagement position in which the slip blocks are seated within a slip bowl of the slip spool so that a weight of the suspended tubing string causes the slip blocks to tightly grip the tubing string. The slip spool facilitates positioning and repositioning of the tubing string in the wellbore and can be used for supporting or snubbing a tubing string in a live well bore.

Abstract: A retrievable frac mandrel and a well control adapter are used to efficiently accomplish well completion, re-completion or workover. The retrievable frac mandrel is inserted in a tubing head spool of a well to be completed, re-completed or re-worked. The well control adapter is mounted to a top of the tubing head spool and seals off against a top of the retrievable frac mandrel. After well completion, re-completion or workover is completed, the frac mandrel can be retrieved from the tubing head spool without killing or plugging the well.

Abstract: An erosion resistant frac head with a convergence chamber, an expansion chamber and a mixing chamber provides improved resistance to erosion caused by abrasive frac fluids pumped through the frac head. A bottom leg of the erosion resistant frac head may be replaced in the field by field hands. Top entry ports of the frac head may also be replaced in the field by field hands.

Abstract: A hybrid wellhead system is assembled using a plurality of threaded unions, such as spanner nuts or hammer unions, for securing respective tubular heads and a flanged connection for securing a flow control stack to a top of a tubing head spool. The tubing head spool is secured by a threaded union to an intermediate head spool. The intermediate head spool is secured by another threaded union to a wellhead. Each tubular head secures and suspends a tubular string in the well bore. The hybrid wellhead system is capable of withstanding higher fluid pressures than a conventional independent screwed wellhead, while providing a more economical alternative to a flanged, or ranged, wellhead system because it is less expensive to construct and faster to assemble.

Abstract: A retrievable frac mandrel and a well control stack are used to efficiently accomplish well completion, re-completion or workover. The retrievable frac mandrel is inserted in a tubing head spool of a well to be completed, re-completed or re-worked. The well control stack is mounted to a top of the tubing head spool and seals off against a top of the retrievable frac mandrel. Once well completion, re-completion or workover is completed, the frac mandrel can be retrieved from the tubing head spool without killing or plugging the well.

Abstract: A plug valve has a valve body, a cage fitted within the valve body and a rotatable plug housed within a cylindrical cavity in the cage, for controlling fluid flow through the valve. The cage has first and second opposed flat side surfaces, each side surface has a port for receiving a replaceable flow-path insert in a fluid-tight seal. In one embodiment, the plug also includes at least one inset seal for sealing the at least one of the ports when the plug is in a closed position to inhibit leakage through the valve at low fluid pressures.

Abstract: A multi-lock adapter used to inject high-pressure well stimulation fluids through an independent screwed wellhead includes an adapter pin having a central passageway with an internal diameter at least as large as a passageway through the wellhead. A lockdown flange secures the adapter pin to a casing mandrel of the wellhead. The lockdown flange ensures that stress on connection points to the screwed independent wellhead due to elevated fluid pressures used for well stimulation procedures does not exceed engineered specifications.

Abstract: A two-part back cap for a plug valve includes a back cap seal body and a back cap retainer nut. The back cap retainer nut secures the back cap seal body within the plug valve and securely supports the back cap seal body. A gap between an outer periphery of the back cap retainer nut and the back cap seal body permits the back cap seal body to flex and expand with a plug valve body of the plug valve. This ensures that the back cap seals are not stressed and a longer service life results.

Abstract: A snubber spool with detachable base plates includes a base flange with a plurality of spaced-apart load pins received in through bores in the base plates. Tie plates with bores for receiving top ends of the load pins are mounted over the base plates in an offset orientation with respect to the base plates. A load nut that engages a pin thread on an outer sidewall of the snubber spool is tightened down on the tie plates to lock the base plates to the snubber spool.

Abstract: A slip spool includes radially disposed actuators for radially moving slip blocks between a loose encirclement position in which they surround the tubing string and a cached position in which the slip blocks clear an axial passage of the slip spool. The slip spool further includes axially disposed actuators for axially displacing the slip blocks between the loose encirclement position and an engagement position in which the slip blocks are seated within a slip bowl of the slip spool so that a weight of the suspended tubing string causes the slip blocks to tightly grip the tubing string. The slip spool facilitates positioning and repositioning of the tubing string in the wellbore and can be used for supporting or snubbing a tubing string in a live well bore.

Abstract: A hybrid wellhead system is assembled using a plurality of threaded unions, such as spanner nuts or hammer unions, for securing respective tubular heads and a flanged connection for securing a flow control stack to a top of a tubing head spool. The tubing head spool is secured by a threaded union to an intermediate head spool. The intermediate head spool is secured by another threaded union to a wellhead. Each tubular head secures and suspends a tubular string in the well bore. The hybrid wellhead system is capable of withstanding higher fluid pressures than a conventional independent screwed wellhead, while providing a more economical alternative to a flanged, or ranged, wellhead system because it is less expensive to construct and faster to assemble.

Abstract: A cup tool includes a cup tool tube having a threaded upper end for connection to a high-pressure mandrel, an outer surface over which an elastomeric cup is slidably mounted for reciprocal movement from an unset position for entry into a wellbore to a set position in which an annular gap is obstructed to contain fluid pressure below the elastomeric cup. The outer surface of the cup tool tube has a lower region of a first diameter and an upper region with a second, larger diameter and a tapered region between the upper region and the lower region. The elastomeric cup includes a lip seal that rides against the outer surface of the cup tool tube, and seals against the tapered region of the cup tool tube to provide a high pressure seal between the cup tool tube and the elastomeric cup in the set position.

Abstract: A multi-lock adapter used to inject high-pressure well stimulation fluids through an independent screwed wellhead includes an adapter pin having a central passageway with an internal diameter at least as large as a passageway through the wellhead. A lockdown flange secures the adapter pin to a casing mandrel of the wellhead. The lockdown flange ensures that stress on connection points to the screwed independent wellhead due to elevated fluid pressures used for well stimulation procedures does not exceed engineered specifications.

Abstract: A high-pressure plug valve is refurbished by replacing a valve plug, a valve plug cage, and flow path inserts that line a flow path through the plug valve. The valve plug cage has first and second opposed flat side surfaces, each side surface has a port for receiving one of the replaceable flow-path inserts in a fluid-tight seal. In one embodiment, refurbishing the plug valve includes replacing at least one inset seal for sealing at least one of the ports when the plug is in a closed position to inhibit leakage through the valve at low fluid pressures.

Abstract: A metal ring gasket provides a high-pressure temperature tolerant metal-to-metal seal between subcomponents of a threaded union. The metal ring gasket is received in an annular cavity formed between mating surfaces of the subcomponents of the threaded union. The metal ring gasket is capable of maintaining a fluid seal even at very high temperatures resulting from direct exposure to fire. At high fluid pressures the metal ring gasket is energized because hoop stress induced by the fluid pressure forces the metal ring gasket into tighter contact with the subcomponents of the threaded union.

Abstract: A two-part back cap for a plug valve includes a back cap seal body and a back cap retainer nut. The back cap retainer nut secures the back cap seal body within the plug valve and securely supports the back cap seal body. A gap between an outer periphery of the back cap retainer nut and the back cap seal body permits the back cap seal body to flex and expand with a plug valve body of the plug valve. This ensures that the back cap seals are not stressed and a longer service life results.

Abstract: Fracturing heads with one or more replaceable wear-resistant inserts have annular sealing elements for inhibiting fracturing fluids from circulating between the inserts and a main body of the fracturing head. Worn inserts and degraded sealing elements are easily replaced to refurbish the fracturing head without replacing or rebuilding the main body. Service life of the main body is therefore significantly prolonged. In one embodiment, an entire flow path through the main body is lined with wear-resistant replaceable inserts to further prolong the service life of the main body.

Abstract: A cup tool for use with a high-pressure mandrel of a wellhead isolation tool has a three-part packoff assembly that slides over a cup tool tube from an unset position to a set position. The three-part packoff assembly includes an elastomeric cup, a rigid alignment ring located above the elastomeric cup and an elastomeric packoff element located above the rigid alignment ring. The rigid alignment ring helps ensure that the elastomeric cup remains correctly aligned in a casing or tubing that is not straight, is out of round or is washed, and helps ensure that the elastomeric packoff achieves a high-pressure seal in the set position, even under adverse downhole conditions.

Abstract: A metal ring gasket provides a high-pressure temperature tolerant metal-to-metal seal between subcomponents of a threaded union. The metal ring gasket is received in an annular cavity formed between mating surfaces of the subcomponents of the threaded union. The metal ring gasket is capable of maintaining a fluid seal even at very high temperatures resulting from direct exposure to fire. At high fluid pressures the metal ring gasket is energized because hoop stress induced by the fluid pressure forces the metal ring gasket into tighter contact with the subcomponents of the threaded union.

Abstract: A drilling flange and an independent screwed wellhead provides a metal-to-metal seal that supplements the traditional elastomeric O-rings for providing a fluid seal between the drilling flange and the wellhead. The metal-to-metal seal may be achieved using a metal ring gasket or two contacting metal surfaces that are machined to required tolerances and are configured to be forced together when the drilling flange is mounted to the wellhead. The metal-to-metal seal ensures a fluid seal between the flange body and the wellhead in the event that the O-rings malfunction or are destroyed by fire.