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.

Abstract: A gate valve includes a valve body having a cylindrical passage defining a flow path through the valve, a gate for controlling fluid flow through the valve and a replaceable wear-resistant flow-path liner for in the flow path. The flow-path liner includes a plurality of replaceable wear-resistant inserts, including wear sleeves lining ports of the valve body, valve seats and a gate insert for a flow path bore through the gate. Each replaceable valve seat has a wiper ring for cleaning the gate when it opens and closes. By regularly inspecting and replacing worn-out inserts, the service life of the gate valve can be prolonged and the expense associated with replacing or rebuilding the valve body is avoided.

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 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 gate valve includes a valve body having a cylindrical passage defining a flow path through the valve, a gate for controlling fluid flow through the valve and a replaceable wear-resistant flow-path liner for in the flow path. The flow-path liner includes a plurality of replaceable wear-resistant inserts, including wear sleeves lining ports of the valve body, valve seats and a gate insert for a flow path bore through the gate. Each replaceable valve seat has a wiper ring for cleaning the gate when it opens and closes. By regularly inspecting and replacing worn-out inserts, the service life of the gate valve can be prolonged and the expense associated with replacing or rebuilding the valve body is avoided.

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 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 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.

Abstract: An apparatus for controlling vertical movement of a tubular within a wellhead includes an anchor spool connected atop the wellhead, and a detachable superstructure supporting the tubular. The anchor spool provides connectors for detachably connecting bottom ends of at least two piston cylinders of the detachable superstructure. The tubular may be a landing joint or a high-pressure mandrel of either a well stimulation tool, or a well isolation tool. The apparatus provides unobstructed access to a top end of the tubular. The anchor spool includes an elongated sidewall and an axial passage through which a tubing hanger can be reciprocated. The height of the sidewall permits the apparatus to be used for landing/removing a tubing string even if the anchor spool is mounted directly to a blowout preventer (BOP).

Abstract: A test plug tool for use in testing a pressure integrity of a pressure control stack mounted to a wellhead, including a joint between a casing and a casing support in the wellhead. The test plug tool includes a test plug of an appropriate diameter used to pressure test the pressure control stack as well as a joint between any one of a surface casing and the wellhead, an intermediate casing and an intermediate casing mandrel, and a production casing and a production casing mandrel. The pressure integrity of the wellhead is ensured at each stage of well drilling and well completion, and safety is improved. Optionally, a backpressure valve permits pressurized fluid that leaks below the test plug tool to flow upwardly through a central bore in a landing tool that is secured to the test plug tool to permit detection of the leak.

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 pack off 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 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 casing mandrel for an independent screwed wellhead includes a pin thread adapted for engagement with a box thread of a well stimulation tool lockdown nut for securing the well stimulation tool against the casing mandrel top end. A well stimulation tool and a tubing head spool for use with the casing mandrel are also provided.

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 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 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.

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.

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.