Portable workover rig with extendable mast substructure, platform mounted drawworks and adjustable wellhead anchor

A transportable mast assembly comprising, in combination:

• a trailer having a load bearing frame including a rear deck for supporting hoist operations and a forward deck having a coupling member for towing engagement with a tractor;
• an elongated mast having a base portion and a crown portion;
• an intermediate support base including a carriage assembly and a cantilever portion projecting from the carriage assembly;
• means coupled intermediate the rear deck and the carriage assembly for moving the intermediate support base from a transport position in generally parallel alignment with and overlying the rear deck to an elevated operating position in generally parallel alignment with the rear deck wherein the cantilever portion is extended beyond the tailboard of the rear deck;
• means connecting the base portion of the mast in hinged engagement with the cantilever portion for permitting pivotal movement of the mast from a reclining transport position overlying the rear and forward decks to an erect hoist position extending above and resting in load bearing engagement upon the cantilever portion;
• and,
• means coupled intermediate the carriage assembly and the base section of the mast for driving the mast in pivotal movement about the hinge means from the reclining transport position to the erect hoist position.

Drawworks for lifting a load comprising:

• a base platform;
• a mast standing erect on the base platform;
• load engaging means disposed for reciprocal movement through a vertical load lifting zone intermediate the base platform and the top of the mast;
• a power transmission system for raising and lowering a load transported by the load engaging means including first and second cable systems coupled intermediate the load engaging means and the base platform, fixed sheave means mounted on the mast engaging the cable systems and guiding the load engaging means through the load lifting zone, and traveling sheave means engaging the first and second cable systems, respectively, and mounted for movement along the base platform through a stroke pathway which extends transversely with respect to the load lifting zone, whereby the load engaging means moves in response to movement of the traveling sheave means;
• and,
• extensible linear actuator means carried on the base platform having rod and housing elements, one of the elements being anchored to the platform and the other element carrying the traveling sheave means through the transverse stroke pathway for displacing the load engaging means through the load lifting zone in response to extension of the rod and housing elements relative to each other.

Draw works for a hoist rig of the type including a horizontally extending base platform and a mast standing on the base platform comprising, in combination:

• a crown block supported on the mast at a predetermined elevation above the base platform;
• a traveling block disposed for reciprocal movement along the mast through a vertical load lifting zone intermediate the base platform and the crown block;
• first and second crown sheaves rotatably mounted on the crown block;
• first and second base sheaves rotatably mounted on the base platform;
• a linear hydraulic actuator carried on said base platform having rod and housing elements, one of the elements being anchored to the base platform and the other element being supported for reciprocal movement along a stroke pathway extending transversely with respect to the load lifting zone;
• first and second traveling sheaves rotatably mounted on the movable actuator element;
• and,
• first and second cables each having a first end portion attached to the traveling block, a second end portion anchored to the base platform, and an intermediate portion being successively reeved around the first and second crown sheaves, respectively, thence around the first and second base sheaves, respectively, and finally around the first and second traveling sheaves, respectively.

Draw works for lifting pipe from a well or for snubbing pipe into a well against the pressure of the well comprising:

• a base platform;
• an upright mast anchored to the base platform;
• pipe engaging means movable along the mast having slip means for engaging the pipe and transmitting a snubbing force against the pipe in response to downward movement of the pipe engaging means and for transmitting a lifting force against the pipe in response to upward movement of the pipe engaging means;
• a linear hydraulic actuator carried on said base platform having rod and housing elements, one of the elements being anchored to the base platform and the other element being supported for extension and retraction along a stroke pathway extending transversely with respect to the mast;
• a traveling hoist sheave assembly journalled on the movable actuator element;
• a traveling snub sheave assembly journalled on the movable actuator element;
• a platform snub sheave assembly journalled on the base platform in the stroke pathway forward of the position reached by the traveling snub sheave assembly at the limit of its travel in extension;
• a hoist power transmission system for driving the pipe engaging means upwardly along the mast including a crown hoist sheave assembly journalled near the top of the mast, a base hoist sheave assembly journalled near the bottom of the mast, and hoist cable means having a first end portion connected to the top of the pipe engaging means, a second end portion anchored to the base platform in the stroke pathway aft of the position reached by the traveling hoist sheave assembly at the limit of its travel in retraction, and an intermediate length extending upwardly along the mast, passing around the crown sheave means, extending downwardly along the mast and passing around the base hoist sheave assembly, extending forward along the base platform in parallel with the stroke pathway, passing around the traveling hoist sheave assembly and extending aft along the base platform to the anchor point;
• and,
• a snub power transmission system for driving the pipe engaging means downwardly along the mast including a crown snub sheave assembly journalled near the top of the mast, first and second base snub sheave assemblies journalled near the bottom of the mast, and snub cable means having a first end portion connected to the bottom of the pipe engaging means, a second end portion anchored to the base platform forward of the position reached by the traveling snub sheave assembly at the limit of its travel in extension, and an intermediate length extending from the pipe engaging means extending downwardly from the pipe engaging means along the mast, passing around the first base snub sheave assembly, extending upwardly along the mast in parallel with the hoist cable means, passing around the crown snub sheave assembly, extending downwardly along the mast in parallel with the hoist cable means, passing around the second base snub sheave assembly, extending forward along the base platform and passing around the platform snub sheave assembly, extending aft along the base platform and passing around the traveling snub sheave assembly, and extending forward along the base platform to the snub anchor point.

Draw works comprising:

• a base platform;
• an upstanding mast anchored to the base platform having structurally interconnected mast sections defining a vertical load transport zone along one side of the mast;
• a traveling block including releasable slip means for gripping and exerting an upwardly or a downwardly directed force on a tubular member extending through the slip means;
• a linear hydraulic actuator having rod and cylinder elements, one of the elements being anchored to the base platform and the other element being disposed for reciprocal movement along a stroke pathway extending generally parallel with the base platform;
• a power transmission system for transporting the traveling block through the load transport zone including first and second traveling sheave assemblies journalled on the movable actuator element, first and second cable systems attached to vertically opposite sides of the traveling block and anchored to the base platform forward and aft of the positions reached by the traveling sheave assemblies during extension and retraction, respectively, first and second guide sheave assemblies journalled on the mast and on the base platform for guiding intermediate lengths of the first and second cable systems along parallel paths through the load transport zone and in parallel relation along the stroke path, an intermediate portion of the first cable system being disposed in reeved engagement with the first traveling sheave assembly and extending aft along the stroke path to the aft anchor point, and an intermediate portion of the second cable system being disposed in reeved engagement with the second traveling sheave assembly and extending forwardly along the stroke path to the forward anchor point, whereby the traveling block is driven upwardly and downwardly through the load transport zone in response to extension and retraction of the rod and housing elements, respectively.

Draw works for hoisting or snubbing a load comprising:

• a base platform;
• a mast standing erect on the base platform;
• load engaging means disposed for reciprocal movement through a vertical load transport zone intermediate the base platform and the top of the mast;
• a power transmission system for raising and lowering a load transported by the load engaging means including first and second cable systems coupled intermediate the load engaging means and the base platform, fixed sheave means journalled on the mast separately engaging the cable systems and guiding the load engaging means through the load transport zone, traveling sheave means separately engaging the first and second cable systems, respectively, and disposed for movement along the base platform through a stroke pathway which extends transversely with respect to the load transport zone, and fixed sheave means journalled on the base platform separately engaging the first and second cable systems and guiding the cable systems along separate runs aft and forward of the traveling sheave means, respectively, whereby the load engaging means is driven upwardly and downwardly in response to reciprocal movement of the traveling sheave means through the stroke pathway;
• and
• a linear hydraulic actuator carried on the base platform having rod and housing elements, one of the elements being anchored to the platform and the other carrying the traveling sheave means through the transverse stroke pathway, whereby the load engaging means is driven upwardly or downwardly through the load transport zone in response to extension and retraction of the rod and housing elements relative to each other, respectively.

Draw works for hoisting or snubbing a pipe string load comprising:

• a base platform;
• a mast standing erect on the base platform;
• load engaging means disposed for reciprocal movement through a vertical load transport zone intermediate the base platform and the top of the mast;
• a linear hydraulic actuator having rod and cylinder elements, one of the elements being anchored to the base platform and the other element being movable along a stroke pathway extending transversely with respect to the load transport zone;
• and,
• a power transmission system for driving the load engaging means through the load transport zone, the power transmission system including sheave means separately journalled on the mast, base platform and movable actuator element, respectively, hoist and snub cables coupled intermediate the load engaging means and the base platform, with intermediate portions of the hoist and snub cables being disposed in reeved engagement with the sheave means, whereby the hoist and snub cables coact with the sheave means for driving the load engaging means through the load transport zone in response to extension and retraction of the actuator elements.

In a workover rig for use with an oil well having an outer casing adapted to receive an inner pipe string and a well head including a flange connector coupled to the outer casing, the workover rig having a mast structure for vertical disposition above the well head, pipe engaging means disposed for reciprocal movement through a load transport zone along the mast, means for driving the pipe engaging means through the load transport zone while transferring the load imposed on the pipe engaging means to the mast, and structure for supporting the mast in an erect position overlying the well head, the combination with the mast support structure of a vertically adjustable stack assembly interposed between the mast and the well head flange connector for transmitting mast loads to the casing, the vertically adjustable stack assembly comprising:

• a stack flange connector for engaging the well head flange connector;
• first coupling means interconnecting the stack flange connector and the mast support structure, the length of the first coupling means being adjustable to drive the stack flange connector into compressive engagement with the well head flange connector;
• and,
• second coupling means interconnecting the stack flange connector and the mast, the length of the second coupling means being vertically adjustable to transfer the weight of the mast from the mast support structure to the well casing.

In a workover rig for use with an oil well having an outer casing adapted to receive an inner pipe string and a well head including a flange connector coupled to the outer casing, the workover rig having a mast structure for vertical disposition above the well head, pipe engaging means disposed for reciprocal movement through a load transport zone along the mast, means for driving the pipe engaging means through the load transport zone while transferring the load imposed on the pipe engaging means to the mast, the combination with the mast of a stack assembly interposed between the mast and the well head flange connector for transmitting loads imposed on the mast by the pipe engaging means to the casing, the stack assembly comprising:

• a stack flange connector for engaging the well head flange connector;
• load coupling means interconnecting the stack flange connector and the mast;
• and,
• a bolster assembly attached to the load coupling means for providing lateral support for a length of inner pipe string extending between the mast and the well head flange.

A well drilling rig comprising, in combination:

• a rigid mast structure for disposition vertically above a bore hole site;
• pipe engaging means movable along the mast having an opening through which a tubular drill string including collars may pass and slip means for engaging the drill string to support the drill string and transmit vertical forces;
• means for moving the pipe engaging means along the mast to raise and lower the pipe engaging means including a rotatable drill sub for stabbing engagement with the tubular drill string;
• a drill power assembly movable along the mast in alignment with the bore hole axis above the pipe engaging means;
• vertically yieldable support means interconnecting the drill power assembly and the pipe engaging means for permitting vertical displacement of the drill power assembly relative to the pipe engaging means while preventing rotation of the drill power assembly due to reacting torque forces on the drill power assembly which arise in response to rotary forces applied to the drill string.

A workover rig for launching and recovering pipe strings in a well comprising, in combination:

• a rig support platform;
• a mast support substructure mounted on the rig support platform for movement from a reclining transport position overlying the rig support platform to an elevated workover position overlying the well;
• an elongated mast pivotally mounted on the mast support substructure for movement from a reclining transport position overlying the rig support platform to an erect workover position overlying and engaging the mast support substructure;
• first power means operatively coupled intermediate the rig support platform and the mast support substructure for selectively moving the mast support substructure between the transport position and the elevated workover position;
• second power means operatively coupled intermediate the mast support substructure and the mast for selectively moving the mast from the reclining transport position and the erect workover position;
• load engaging means disposed for reciprocal movement through a vertical load transport zone intermediate the mast support substructure and the top of the mast;
• a linear hydraulic actuator having rod and cylinder elements, one of the elements being anchored to rig base platform and the other element being movable along a stroke pathway extending transversely with respect to the load transport zone;
• and,
• a power transmission system for driving the load engaging means through the load transport zone, the power transmission system including sheave means separately journalled on the mast, rig platform and movable actuator element, respectively, hoist and snub cables coupled intermediate the load engaging means and the rig platform, with intermediate portions of the hoist and snub cables being disposed in reeved engagement with the sheave means, whereby the hoist and snub cables coact with the sheave means for driving the load engaging means through the load transport zone in response to extension and retraction of the actuator elements.

A workover rig for launching and recovering pipe strings in an offshore well comprising, in combination:

• a barge transportable skid for offshore duty;
• a mast pivotally coupled to the skid for erection from a reclining transport position to an upright workover position, the mast having structurally interconnected mast sections defining a load transport zone along the mast;
• a traveling block including releasable slip means for gripping and exerting an upwardly or a downwardly directed force on a tubular member extending through the slip means;
• a linear hydraulic actuator having rod and cylinder elements, one of the elements being anchored to the skid and the other element being disposed for reciprocal movement along a stroke pathway extending generally parallel with the skid;
• and,
• a power transmission system for driving the traveling block through the load transport zone, the power transmission system including sheave means separately journalled on the mast, rig platform and movable actuator element, respectively, hoist and snub cables coupled intermediate the load engaging means and the rig platform, with intermediate portions of the hoist and snub cables being disposed in reeved engagement with the sheave means, whereby the hoist and snub cables coact with the sheave means for driving the load engaging means through the load transport zone in response to extension and retraction of the actuator elements.

In a workover rig adapted for use with a well having an outer well pipe enclosing casing terminating at a flanged well head, support structure for a transportable mast comprising:

• a trailer having a load bearing frame including a rear deck for supporting hoist operations and a forward deck having a coupling member for towing engagement with a tractor;
• first and second pairs of ground engaging jacks secured to the forward and rear decks, respectively, for stabilizing the load bearing frame of the trailer during workover operations;
• an intermediate mast support base including a carriage assembly and a cantilever portion projection from the carriage assembly;
• first and second struts having ground engaging stabilizer pads coupled in hinged engagement with the cantilever portion of the intermediate support base, first and second chains connected intermediate the load bearing trailer frame and the struts, respectively, a third chain connected intermediate the first and second struts, and means coupled to each chain for adjusting its effective length;
• means coupled intermediate the rear deck and the carriage assembly for moving the intermediate support base from a transport position overlying the rear deck to an elevated operating position wherein the cantilever portion is extended beyond the tailboard of the rear deck;
• means connecting the base portion of the mast in hinged engagement with the cantilever portion for permitting pivotal movement of the mast from a reclining transport position overlying the rear and forward decks to an erect hoist position extending above and resting in load bearing engagement upon the cantilever portion;
• means coupled intermediate the carriage assembly and the base section of the mast for driving the mast in pivotal movement about the hinge means from the reclining transport position to the erect hoist position;
• a stack flange connector for engaging the well head flange connector;
• first coupling means anchoring the stack flange connector to the trailer frame, the length of the first coupling means being adjustable to drive the stack flange connector into compressive engagement with the well head flange connector;
• and,
• second coupling means anchoring the stack flange connector to the intermediate mast support base, the length of the second coupling means being vertically adjustable to transfer the weight of the mast from the mast support structure to the well casing.

A workover rig for launching and recovering pipe strings in a well comprising, in combination:

• a rig support platform;
• a mast support structure mounted on the rig support platform for movement from a reclining transport position overlying the rig support platform to an elevated workover position overlying the well;
• an elongated mast pivotally mounted on the mast carriage assembly for movement from a reclining transport position overlying the rig support platform to an erect workover position overlying and engaging the mast support substructure;
• first power means operatively coupled intermediate the rig support platform and the mast support assembly for selectively moving the mast support substructure between the transport position and the elevated workover position;
• second power means operatively coupled intermediate the mast support assembly and the mast for selectively moving the mast from the reclining transport position and the erect workover position;
• load engaging means disposed for reciprocal movement through a vertical load transport zone intermediate the mast support substructure and the top of the mast;
• a linear hydraulic actuator having rod and cylinder elements, one of the elements being anchored to rig base platform and the other element being movable along a stroke pathway extending transversely with respect to the load transport zone;
• and
• a power transmission system for driving the load engaging means through the load transport zone, the power transmission system including:
• a traveling hoist sheave assembly journalled on the movable actuator element;
• a traveling snub sheave assembly journalled on the movable actuator element;
• a platform snub sheave assembly journalled on the rig support platform in the stroke pathway forward of the position reached by the traveling snub sheave assembly at the limit of its travel in extension;
• a hoist power transmission system for driving the pipe engaging means upwardly along the mast including a crown hoist sheave assembly journalled near the top of the mast, a base hoist sheave assembly journalled near the bottom of the mast, and hoist cable means having a first end portion connected to the top of the pipe engaging means, a second end portion anchored to the base platform in the stroke pathway aft of the position reached by the traveling hoist sheave assembly at the limit of its travel in retraction, and an intermediate length extending upwardly along the mast, passing around the crown sheave means, extending downwardly along the mast and passing around the base hoist sheave assembly, extending forward along the rig support platform in parallel with the stroke pathway, passing around the traveling hoist sheave assembly and extending aft along the rig support platform to the anchor point;
• and,
• a snub power transmission system for driving the pipe engaging means downwardly along the mast including a crown snub sheave assembly journalled near the top of the mast, first and second base snub sheave assemblies journalled near the bottom of the mast, and snub cable means having a first end portion connected to the bottom of the pipe engaging means, a second end portion anchored to the rig support platform forward of the position reached by the traveling snub sheave assembly at the limit of its travel in extension, and an intermediate length extending from the pipe engaging means extending downwardly from the pipe engaging means along the mast, passing around the first base snub sheave assembly, extending upwardly along the mast in parallel with the hoist cable means, passing around the crown snub sheave assembly, extending downwardly along the mast in parallel with the hoist cable means, passing around the second base snub sheave assembly, extending forward along the base platform and passing around the platform snub sheave assembly, extending aft along the rig support platform and passing around the traveling snub sheave assembly, and extending forward along the rig support platform to the snub anchor point.

A workover rig for launching and recovering pipe strings in an offshore well comprising, in combination:

• a barge transportable skid for offshore duty;
• a mast pivotally coupled to the skid for erection from a reclining transport position to an upright workover position, the mast having structurally interconnected mast sections defining a load transport zone along the mast;
• a traveling block including releasable slip means for gripping and exerting an upwardly or a downwardly directed force on a tubular member extending through the slip means;
• a linear hydraulic actuator having rod and cylinder elements, one of the elements being anchored to the skid and the other element being disposed for reciprocal movement along a stroke pathway extending generally parallel with the skid;
• and,
• a power transmission system for driving the traveling block through the load transport zone, the power transmission system including:
• a traveling hoist sheave assembly journalled on the movable actuator element;
• a traveling snub sheave assembly journalled on the movable actuator element;
• a platform snub sheave assembly journalled on the base platform in the stroke pathway forward of the position reached by the traveling snub sheave assembly at the limit of its travel in extension;
• a hoist subsystem for driving the pipe engaging means upwardly along the mast including a crown hoist sheave assembly journalled near the top of the mast, a base hoist sheave assembly journalled near the bottom of the mast, and hoist cable means having a first end portion connected to the top of the pipe engaging means, a second end portion anchored to the base platform in the stroke pathway aft of the position reached by the traveling hoist sheave assembly at the limit of its travel in retraction, and an intermediate length extending upwardly along the mast, passing around the crown sheave assembly, extending downwardly along the mast and passing around the base hoist sheave assembly, extending downwardly along the mast and passing around the base hoist sheave assembly, extending forward along the base platform in parallel with the stroke pathway, passing around the traveling hoist sheave assembly and extending aft along the base platform to the anchor point;
• and,
• a snub subsystem for driving the pipe engaging means downwardly along the mast including a crown snub sheave assembly journalled near the top of the mast, first and second base snub sheave assemblies journalled near the bottom of the mast, and snub cable means having a first end portion connected to the bottom of the pipe engaging means, a second end portion anchored to the base platform forward of the position reached by the traveling snub sheave assembly at the limit of its travel in extension, and an intermediate length extending from the pipe engaging means downwardly along the mast, passing around the first base snub sheave assembly, extending upwardly along the mast in parallel with the hoist cable means, passing around the crown snub sheave assembly, extending downwardly along the mast in parallel with the hoist cable means, passing around the second base snub sheave assembly, extending forward along the base platform and passing around the platform snub sheave assembly, extending aft along the base platform and passing around the traveling snub sheave assembly, and extending forward along the base platform to the snub anchor point.