Screw-driven wellhead isolation tool

A wellhead isolation tool for injecting substances through a passage defined by a wellhead into a well, the wellhead isolation tool comprising:

• a mandrel defining a mandrel passage, the mandrel having an outer surface and a longitudinal central axis;
• a valve connected to an upper end of the mandrel, the valve having an open and a closed position, wherein the substances to be injected may be communicated through the valve into the mandrel passage when the valve is in the open position;
• a threaded drive rod positioned above the valve and operably associated therewith, so that up-and-down movement of the threaded drive rod causes the mandrel to reciprocate in and out of the well through the passage defined by the wellhead, the threaded rod being coaxial with the mandrel;
• and
• a drive mechanism for moving the threaded drive rod vertically so that the mandrel is moved in and out of the well.

A wellhead isolation tool for injecting substances through a wellhead into a well, the wellhead defining a longitudinal passage therethrough, the wellhead isolation tool comprising:

• a mandrel defining a mandrel flow passage for the substances to be injected, the mandrel having a lower end sealingly engageable with a tubular element in the well;
• at least one valve connected to an upper end of the mandrel, wherein the substances may be communicated into the mandrel flow passage when the at least one valve is in an open position;
• a drive rod releasably connected to the at least one valve for reciprocating the mandrel into and out of the well through the longitudinal passage in the wellhead;
• a lower hub having a passage through which the mandrel passes;
• a wellhead adapter connected to the lower hub for connection to the wellhead;
• and
• a removable support structure for supporting the at least one valve and the mandrel while the mandrel is urged through the wellhead, the support structure comprising:
• a lower support plate having a vertical support member extending upwardly therefrom, the lower support plate defining a plurality of openings therethrough, the lower hub having a plurality of mating openings, wherein pins may be removably inserted into the openings in the lower hub and the lower support plate, and wherein the support structure may be disconnected and removed by removing the pins and disconnecting the drive rod from the at least one valve after the wellhead adapter is connected to the wellhead.

A wellhead isolation tool comprising:

• a mandrel for reciprocating through a wellhead into a tubular element disposed in a well below the wellhead;
• a valve connected to the mandrel and movable therewith;
• a wellhead adapter for connecting the wellhead isolation tool to the wellhead, wherein the mandrel is movable in the wellhead adapter;
• and
• a wellhead adapter sub, the wellhead adapter sub having a bolt hole pattern adapted to match a bolt pattern on an upper end of the wellhead, the wellhead adapter sub having a threaded upper end for mating with threads on the wellhead adapter so that the wellhead adapter sub may be bolted to the wellhead, wherein the wellhead isolation tool may be connected to the wellhead by threadedly connecting the wellhead adapter to the wellhead adapter sub.

A wellhead isolation tool for injecting substances through a passage defined by a wellhead into a well, the wellhead isolation tool comprising:

• a mandrel defining a mandrel flow passage for the substances to be injected, the mandrel being movable between an upper position wherein the mandrel is retracted from the wellhead and a lower position wherein a lower end of the mandrel is received in an element in the well;
• a valve connected to the mandrel and movable therewith;
• a drive rod connected to the valve for moving the mandrel between its upper and lower positions;
• an upper hub, the drive rod being movably disposed in the upper hub;
• a lower hub, the mandrel being movably disposed in the lower hub;
• a wellhead adapter that connects the lower hub to the wellhead;
• and
• a support structure for supporting the mandrel as the mandrel is being inserted into or withdrawn from the well through the wellhead, the support structure comprising:
• an upper support plate connectable to the upper hub;
• a lower support plate releasably connectable to the lower hub;
• and
• a vertical support frame connected to the upper and lower support plates, wherein the lower support plate, the upper hub, the drive rod, and the support structure can be moved as a unit after the mandrel is moved to its lower position by disconnecting the lower support plate from the lower hub and releasing the drive rod from the valve.

A wellhead isolation tool for injecting substances through a passage defined by a wellhead into a well, the wellhead isolation tool comprising:

• an upper hub;
• a drive rod movably disposed in the upper hub;
• at least one valve releasably connected to the drive rod;
• a mandrel defining a flow passage positioned below the at least one valve, the at least one valve having a closed position and an open position, wherein in the open position the substances to be injected may be communicated through the at least one valve into the mandrel;
• a lower hub, the mandrel being movably disposed in the lower hub;
• a wellhead adapter for connecting the lower hub to the wellhead;
• and
• a support structure comprising:
• an upper support plate releasably connected to the upper hub;
• a lower support plate releasably connected to the lower hub;
• and
• a support frame extending between the upper and lower support plates, wherein the support frame has an outer periphery defining a generally rectangular cross section having a left side, a right side, a rear, and a front.