Abstract: A blowout preventer (BOP) protector is adapted to support a tubing string in a wellbore so that the tubing string is directly accessible during a well treatment to stimulate production. The BOP protector includes a mandrel having a sealing assembly mounted to its bottom end for pack-off in a casing of a well to be stimulated. The mandrel is connected at its top end to a fracturing head, including a central passage and radial passages in fluid communication with the central passage. The mandrel is locked in a fixed position by a lockdown nut that prevents upward movement induced by fluid pressures in the wellbore. The advantages are that the BOP protector permits access to the tubing string during well treatment and enables an operator to move the tubing string up and down or run coil tubing into or out of the wellbore without removing the tool. This reduces operation costs, saves time and enables many new procedures that were previously impossible or impractical.

Abstract: A blowout preventer (BOP) protector is adapted to support a tubing string in a wellbore so that the tubing string is directly accessible during a well treatment to stimulate production. The BOP protector includes a mandrel having a sealing assembly mounted to its bottom end for pack-off in a casing of a well to be stimulated. The mandrel is connected at its top end to a fracturing head, including a central passage and radial passages in fluid communication with the central passage. The mandrel is locked in a fixed position by a lockdown nut that prevents upward movement induced by fluid. pressures in the wellbore. The advantages are that the BOP protector permits access to the tubing string during well treatment and enables an operator to move the tubing string up and down or run coil tubing into or out of the wellbore without removing the tool. This reduces operation costs, saves time and enables many new procedures that were previously impossible or impractical.

Abstract: Apparatus for inserting a tubing hanger into a tubing head spool on a live well includes a landing spool and a landing joint that reciprocates through a top end of the landing spool. The landing joint is connected to the tubing hanger. The landing spool is connected to a top flange of a blowout preventer on the live well. The blowout preventer is then opened and the tubing hanger is injected into the tubing head spool. A lifting spool is also provided to permit the tubing hanger to be injected without the use of a service rig. Safety is improved, costs reduced and production is facilitated because the well does not have to be killed.

Abstract: A slip spool for selectively supporting a tubing string suspended in a wellbore can be mounted to a wellhead. The slip spool has an axial passage that is aligned with the wellbore, and at least two radial passages extending through a side wall of the slip spool and communicating with the axial passage. At least two slip assemblies are slidably received within the respective radial passages. Actuators move the respective slip assemblies between a retracted position in which the slip jaws clear the axial passage of the slip spool, and an extended position in which wedge-shaped slip jaws of the respective slip assemblies are inserted into an annulus between the axial passage of the slip spool to grip the tubing string.

Abstract: A well stimulation tool is connected to a top of a tubing hanger in a well to be stimulated. The well stimulation tool includes an adapter pin that connects to the tubing hanger. The adapter pin is connected to a mandrel that reciprocates through a top end of an adapter spool, which is mounted to a tubing head spool that supports the tubing hanger. A high-pressure valve is mounted to a top end of the mandrel. High-pressure fluids are pumped through the high-pressure valve, the mandrel, the adapter pin, the tubing hanger, and a production tubing into the well.

Abstract: A slip spool for selectively supporting or snubbing a tubing string suspended in a wellbore can be mounted to a wellhead. The slip spool has an axial passage to be aligned with the wellbore and at least two radial passages extending through a side wall of the slip spool and communicating with the axial passage. At least two slip blocks are slidably supported within the respective radial passages. The slip spool further includes actuators for moving the respective slip blocks between an extended position in which they engage a component in the tubing string that provides a weight-bearing shoulder, and a retracted position in which the slip blocks clear the axial passage of the slip spool. The slip spool facilitates live well service operations and eliminates scoring of an exterior surface of the tubing.

Abstract: An apparatus for rigless subterranean well completion, re-completion, servicing or workover includes at least two substantially vertically oriented double acting prime movers incorporated into a spool for pressure containment, which is mounted to the top of a wellhead. The spool further includes a Bowen union mounted to a top thereof for sealingly connecting an annular adapter, which provides a seal between the well bore and a tubular that is inserted under the well fluid pressure into the well by the prime movers. The spool may further include a mechanism for securing a hydraulic crane that can be temporarily mounted to the top of the spool to hoist equipment and tools above the wellhead when the prime movers are used to support heavy workloads induced by well fluid pressure or the weight of a tubing string. The apparatus can be used in various operations for well completion, re-completion, servicing or workover without the necessity of using a servicing rig.

Abstract: A coil tubing injector assembly includes a frame structure and a pair of gripper chain drive systems mounted to the frame structure. The pair of gripper chain drive systems are disposed in a common plane and spaced apart from each other, and adapted to engage a first and a second coil tubing string to inject both of the first and second coil tubing strings into, and withdraw both the first and second strings from, a subterranean well. The first and second coil tubing strings may be injected synchronously or asynchronously depending on the structure of the injector. The coil tubing injector assembly reduces the time required to perform many downhole operations, and therefore reduces well completion, stimulation and re-completion expenses.

Abstract: A seal assembly for dual string coil tubing injection into a subterranean well includes a seal plate having first and second bores with annular seals for providing a high-pressure fluid seal around first and second coil tubing strings inserted through the respective bores. The seal plate is adapted to be connected directly to a wellhead, or a lubricator if a downhole tool is connected to either one, or both of the first and second coil tubing strings. The seal assembly further includes passages for supplying lubricant to the first and second annular seals to lubricate the respective seals while the respective first and second coil tubing strings are injected into and extracted from the wellhead.

Abstract: Perforation and stimulation of a plurality of selected sections of a cased well is completed with a single insertion of a well tool. The process includes successive stages of perforating and stimulating selected sections of the well in sequence starting from a lowest section in the wellbore. In each stage, selected charges carried by a perforating gun of the well tool are detonated to perforate the casing and stimulation fluid is pumped through the perforating gun to an injection nozzle connected to a bottom end of the perforating gun.

Abstract: Apparatus for inserting a tubing hanger into a tubing head spool on a live well includes a landing spool and a landing joint that reciprocates through a top end of the landing spool. The landing joint is connected to the tubing hanger. The landing spool is connected to a top flange of a blowout preventer on the live well. The blowout preventer is then opened and the tubing hanger is injected into the tubing head spool. A lifting spool is also provided to permit the tubing hanger to be injected without the use of a service rig. Safety is improved, costs reduced and production is facilitated because the well does not have to be killed.

Abstract: A seal assembly for dual string coil tubing injection into a subterranean well includes a seal plate having first and second bores with annular seals for providing a high-pressure fluid seal around first and second coil tubing strings inserted through the respective bores. The seal plate is adapted to be connected directly to a wellhead, or a lubricator if a downhole tool is connected to either one, or both of the first and second coil tubing strings. The seal assembly further includes passages for supplying lubricant to the first and second annular seals to lubricate the respective seals while the respective first and second coil tubing strings are injected into and extracted from the wellhead.

Abstract: A blowout preventer (BOP) protector is adapted to support a tubing string in a well bore so that the tubing string is directly accessible during a well treatment to stimulate production. The BOP protector includes a mandrel having an annular sealing body bonded to its bottom end for sealing engagement with a bit guide that protects a top of a casing of a well to be stimulated. The mandrel is connected at its top end to a fracturing head, including a central passage and radial passages in fluid communication with the central passage. The mandrel is locked in a fixed position by a lockdown mechanism that prevents upward movement induced by fluid pressures in the wellbore and downward movement induced by the weight of a tubing string supported at a top of the fracturing head by a tubing adapter.

Abstract: A blowout preventer (BOP) protector featuring a low profile and a mechanical lockdown mechanism is described. The BOP protector includes a mandrel having an annular sealing body bonded to its bottom end for sealing engagement with a bit guide which protects a top of a casing of a well to be stimulated with acidifying or fracturing fluids. The mandrel is locked down with a mechanical lockdown mechanism having a broad range of adjustment. The advantages include a low profile, the security of a mechanical lockdown mechanism, and full access to the casing with downhole tools.

Abstract: High pressure fluid seals for sealing against a bit guide in wellhead and a method of using the seals are described. The high pressure fluid seals are primarily intended for use with a blowout preventer protector. The high pressure fluid seals are elastomeric material bonded to an end of a mandrel for insertion into the wellhead. The end of the mandrel includes an annular ridge that protrudes into the elastomeric seal to inhibit the seal from being extruded away from the bore when the elastomeric seal is seated against the bit guide and the bore is subjected to elevated fluid pressures. The advantage is a high pressure fluid seal that ensures packoff against a bit guide even if the bit guide is worn but still serviceable. A further advantage is a more secure seal that improves safety and enables the use of higher pressures during well stimulation.

Abstract: The present invention relates to a method and apparatus for the servicing or workover of a hydrocarbon well. The apparatus includes a pair of hydraulic cylinders pivotally mounted to a pair of base beams connected to each other. The cylinders are moveable from a horizontal position for transportation to a vertical position for operation in which position the two cylinders flank a wellhead and are adapted to lift the wellhead and attached production tubing using a workover beam and a lifting sub. The wellhead and production tubing can be rotated as or after they are elevated. A motor may be mounted to the workover beam to rotate the wellhead and the tubing. A calibrated pressure gauge may be used to indicate the weight being lifted. The apparatus can be wheel mounted and towed behind a crane truck. The advantage is a safe, economical and timesaving apparatus for performing jobs that previously required the setup and operation of a workover rig.

Abstract: A wellhead isolation tool permitting a high fluid flow rate during a well treatment to stimulate production is described. The wellhead isolation tool includes a mandrel to be inserted into a wellhead. The mandrel is sealed in a tubing hanger above back pressure valve threads to isolate the pressure sensitive components of the wellhead from fluid pressure used in the well treatment, and has a lower section extending past the back pressure valve threads and tubing threads into the tubing to protect the threads from washout. The mandrel is locked down with a mechanical lockdown mechanism having a broad range of adjustment. The advantages are that no special tubing hanger is required for use with the mandrel, and a fluid flow rate enabled by the tool during the well treatment is significantly higher than a fluid flow rate enabled with conventional wellhead isolation tools.

Abstract: An apparatus for securing a mandrel of a well tool in an operative position in which the mandrel is packed off against a fixed-point in the well is described. The apparatus includes a mechanical lockdown mechanism to secure the tool to the wellhead and maintain the mandrel in proximity to the fixed-point for packoff, and a mechanical or a hydraulic mechanism to move the mandrel into the operative position while the mechanical lockdown mechanism is in a lockdown position. A second mechanical locking mechanism is provided to ensure the mandrel is maintained in the operative position in the event that hydraulic pressure is lost. The invention provides a mechanism to lock down well tools requiring fixed-point packoff in a well and advantageously improves the range of adjustment of the lockdown mechanism so that the length of a mandrel may be less precisely matched to a distance from a top of the wellhead to the fixed-point in the well.

Abstract: A dual string well tree isolation apparatus includes two assemblies each having a high pressure valve and a high pressure tubing which are respectively inserted into the vertical passage of a dual string well tree, and a swedge for connection to the dual string well tree for supporting one of the assemblies. The swedge vertically offsets one assembly from the other. The apparatus further includes a hydraulic cylinder for inserting the high pressure tubings and cylinder support rods for removable attachment of the hydraulic cylinder to the dual string well tree. The hydraulic cylinder and the support rods are removed after each insertion of a high pressure tubing into a respective vertical passage to provide easy access to the high pressure valve of each assembly. The advantage is a safe, economical apparatus for simultaneous stimulation of a dual string well completion.

Abstract: An apparatus for increasing the transfer rate of production stimulation fluids through a wellhead of a hydrocarbon well is disclosed. The apparatus includes a mandrel for a wellhead isolation tool and a tubing hanger for use in conjunction with the mandrel. The mandrel includes a bottom end to which an annular seal is bonded. The annular seal cooperates with a sealing surface in a top end of the tubing hanger to isolate the wellhead equipment from the high pressures and corrosive and/or abrasive materials pumped into the well during a production stimulation treatment. The novel construction for the mandrel and the tubing hanger eliminates the requirement for a packoff assembly attached to a bottom of the mandrel and thereby permits the mandrel to have a larger internal diameter for increasing the transfer rate of production stimulation fluids through the wellhead.