Abstract: A subsurface lubricator facilitates well completion, re-completion and workover while increasing safety and reducing expense. The subsurface lubricator includes a bi-directional packoff tool on its bottom end. Short hydraulic cylinders lubricate the subsurface lubricator into the well until the bi-directional packoff tool is in a top end of a casing of the well. High pressure fluid pumped through a side port of a wellhead of the well lubricates the subsurface lubricator into the well.

Abstract: A configurable wellhead system is used to efficiently accomplish well completion, re-completion or workover. The configurable wellhead system includes a permanent fracturing spool that is mounted to a casing head of the well and provides a high pressure seal around a top of a casing of the well. The permanent fracturing spool provides full-bore direct access to the casing without the use of a pressure isolation mandrel. A tubing head is mounted to a top of the permanent fracturing spool to complete the configurable wellhead system. A fracturing spool plug secured in a seal bore of the permanent fracturing spool permits equipment mounted above the permanent fracturing spool to be removed without killing the well or inserting a wireline casing plug.

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 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 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 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: 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 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.

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 configurable wellhead system is used to efficiently accomplish well completion, re-completion or workover. The configurable wellhead system includes a permanent fracturing spool that is mounted to a casing head of the well and provides a high pressure seal around a top of a casing of the well. The permanent fracturing spool provides full-bore direct access to the casing without the use of a pressure isolation mandrel. A tubing head is mounted to a top of the permanent fracturing spool to complete the configurable wellhead system. A fracturing spool plug secured in a seal bore of the permanent fracturing spool permits equipment mounted above the permanent fracturing spool to be removed without killing the well or inserting a wireline casing plug.

Abstract: A subsurface lubricator facilitates well completion, re-completion and workover while increasing safety and reducing expense. The subsurface lubricator includes a bi-directional packoff tool on its bottom end. Short hydraulic cylinders lubricate the subsurface lubricator into the well until the bi-directional packoff tool is in a top end of a casing of the well. High pressure fluid pumped through a side port of a wellhead of the well lubricates the subsurface lubricator into the well.

Abstract: A method of subsurface lubrication facilitates well completion, re-completion and workover while increasing safety and reducing expense. The method involves using a subsurface lubricator mounted to a wellhead of the cased wellbore to lubricate a downhole tool string into the cased wellbore by running a subsurface lubricator through the wellhead and into an upper section of a production casing of the cased wellbore.

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 subsurface lubricator facilitates well completion, re-completion and workover while increasing safety and reducing expense. The subsurface lubricator includes a bi-directional packoff tool on its bottom end. Short hydraulic cylinders lubricate the subsurface lubricator into the well until the bi-directional packoff tool is in a top end of a casing of the well. High pressure fluid pumped through a side port of a wellhead of the well lubricates the subsurface lubricator into the well.