Abstract: Embodiments of the invention provide a system and method for induction heating a helical rotor of a progressing cavity pump in order to reduce the surface roughness of the rotor. In order to heat the rotor most evenly, it is desired to space the coil as closely around the rotor as possible. The invention provides a mechanism for threading the helical rotor through an induction coil having an interior diameter which is less than the major diameter of the rotor. The induction coil may include one loop and overlapping ends. The rotor to be heated is rotated about its longitudinal axis and advanced axially through the coil as it rotates. The axial speed and rotational speed are synchronized so that the rotor moves one pitch through the coil for each complete rotation.

Abstract: Embodiments of the invention provide a system and method for induction heating a helical rotor of a progressing cavity pump in order to reduce the surface roughness of the rotor. In order to heat the rotor most evenly, it is desired to space the coil as closely around the rotor as possible. The invention provides a mechanism for threading the helical rotor through an induction coil having an interior diameter which is less than the major diameter of the rotor. The induction coil may include one loop and overlapping ends. The rotor to be heated is rotated about its longitudinal axis and advanced axially through the coil as it rotates. The axial speed and rotational speed are synchronized so that the rotor moves one pitch through the coil for each complete rotation.

Abstract: Embodiments of the invention provide a system and method for induction heating a helical rotor of a progressing cavity pump in order to reduce the surface roughness of the rotor. In order to heat the rotor most evenly, it is desired to space the coil as closely around the rotor as possible. The invention provides a mechanism for threading the helical rotor through an induction coil having an interior diameter which is less than the major diameter of the rotor. The induction coil may include one loop and overlapping ends. The rotor to be heated is rotated about its longitudinal axis and advanced axially through the coil as it rotates. The axial speed and rotational speed are synchronized so that the rotor moves one pitch through the coil for each complete rotation.

Abstract: A progressing cavity pump assembly includes a collar assembly connecting a housing and a tubing string, with the collar having an inside diameter upset and the rotor having a rotor head axially spaced from a rotor helix, with the rotor head having an outer diameter forming a stop adapted to land on the inside diameter upset. A method of timing a progressing cavity pump assembly includes providing a collar assembly having an inside diameter upset, movably connecting the collar assembly and the housing, providing a rotor having a rotor head axially spaced from a rotor helix, with the rotor head having an outer diameter forming a stop, selectively adjusting the relative position of the collar assembly and the housing to form a pathway substantially corresponding to the rotor helix, landing the stop on the inside diameter upset, and fixing the relative position of the collar assembly and the housing.

Abstract: A drivehead for driving a drive string of a rotary pump or motor includes a bearing housing including lubricating fluid therein, a driveshaft extending through the bearing housing and connectable into drive communication with the drive string, and a concentric pump disposed in the bearing housing about the driveshaft, the concentric pump selected to pump the lubricating fluid through the bearing housing as driven by the driveshaft.

Abstract: A method of hardfacing a metal body, including the steps of flame spraying a metallic material onto a surface of the metal body to produce a layer of the metallic material on the metal body and fusing the layer of metallic material to provide a hardfacing layer, is improved by roughening the surface of the metal body prior to the step of flame spraying to provide a mechanical bond between the metal body and the hardfacing layer. The roughening is carried out to achieve a surface roughness adjusted to the thickness of the hardcoating. The surface roughness is preferably 40%-90% of the thickness of the hardfacing layer.

Abstract: A method of hardfacing a metal body, including the steps of flame spraying a metallic material onto a surface of the metal body to produce a layer of the metallic material on the metal body and fusing the layer of metallic material to provide a hardfacing layer, is improved by roughening the surface of the metal body prior to the step of flame spraying to provide a mechanical bond between the metal body and the hardfacing layer. The roughening is carried out to achieve a surface roughness adjusted to the thickness of the hardcoating. The surface roughness is preferably 40%-90% of the thickness of the hardfacing layer.

Abstract: A drivehead for driving a drive string of a rotary pump or motor includes a bearing housing including lubricating fluid therein, a driveshaft extending through the bearing housing and connectable into drive communication with the drive string, and a concentric pump disposed in the bearing housing about the driveshaft, the concentric pump selected to pump the lubricating fluid through the bearing housing as driven by the driveshaft.

Abstract: A brake assembly permits axial rotation of a shaft in a first direction and retarding axial rotation of the shaft in an opposite, reverse direction. The brake assembly includes a rotary member for mounting to and rotation with the shaft; a fluid actuated brake mechanism for retarding the rotation of the rotary member and consequently the shaft upon pressure build up in the brake mechanism; a bi-direction pump for conveying fluid from a reservoir, the pump being driven by rotation of the shaft; and a control manifold for directing circulating the fluid from the pump through the brake mechanism and back to the reservoir without pressure build up, the circulation of the fluid preventing the accumulation of gas in the brake mechanism, when the shaft turns in the first direction and or directing fluid to the brake mechanism for activating the brake mechanism by fluid pressure build up to retard rotation of the shaft when the shaft turns in the reverse direction.

Abstract: An insertable progressing cavity pump is taught. The pump is insertable in a bore of a tubing string by carriage on a drive string, the insertable progressing cavity pump includes a stator, a helical rotor locatable in the stator and including a coupling for connection to the drive string, a tubular housing for accommodating the stator therein and sized to be insertable into the tubing string, a pump hold-down arrangement in communication with the housing and disposed above the stator for engaging the pump into the tubing string, and a torque transmitting arrangement acting between the rotor and the housing to transmit torque from the rotor to the housing in both the clockwise and counter-clockwise direction, when the housing is carried on the drive string. The insertable progressing cavity pump in another aspect includes a hold down assembly disposed above the stator on the pump housing.

Abstract: An insertable progressing cavity pump is taught. The pump is insertable in a bore of a tubing string by carriage on a drive string, the insertable progressing cavity pump includes a stator, a helical rotor locatable in the stator and including a coupling for connection to the drive string, a tubular housing for accommodating the stator therein and sized to be insertable into the tubing string, a pump hold-down arrangement in communication with the housing and disposed above the stator for engaging the pump into the tubing string, and a torque transmitting arrangement acting between the rotor and the housing to transmit torque from the rotor to the housing in both the clockwise and counter-clockwise direction, when the housing is carried on the drive string. The insertable progressing cavity pump in another aspect includes a hold down assembly disposed above the stator on the pump housing.

Abstract: The invention relates to a braking assembly for permitting axial rotation of a shaft in a first direction and inhibiting axial rotation of the shaft in a second, opposite direction, comprising: a hydraulic clutch having a torque generating member and a torque receiving member wherein the torque generating member is connected to the shaft and the torque receiving member is stationary and a guide means for maintaining the torque generating member in a first de-activated position when the shaft is rotated in the first direction and for moving the torque generating member to a second activated position when the shaft is rotated in the opposite direction whereby activation of the torque generating member inhibits rotation of the shaft in the second direction. The invention provides an effective emergency braking assembly for such systems as progressing cavity pumps in oil wells.

Abstract: A method and apparatus for unblocking particulate plugs that develop in a well that produces fluid laden with suspended particles when a pump in the well is idled are described. In order to remove the plugs, a valve is inserted in the production tubing above the pump, the valve permitting the well fluid to flow up past the valve but inhibiting the well fluid from flowing down past the valve so that a majority of particles that settle from the well fluid when the pump is idle are trapped above the valve and do not plug the pump. A volume of well fluid trapped between the bottom of the valve and the top of the pump permits pressure waves induced by starting and stopping the pump to be generated. The pressure waves force fluids past the valve until the particles in the plug are resuspended to permit production to resume. The advantage is a simple, low cost solution to a long standing problem which required pulling of the production tubing from the well in order to remove the particulate plug.

Abstract: The invention relates to downhole rotary pumping arrangements and more particularly to drivehead gimbals and seals used in the driveheads of downhole rotary pumps. The gimbal and seal system described enables the wobble of a rotating shaft to be absorbed without compromising the seal around the shaft.

Abstract: A hardfacing for downhole progressing cavity pumps is disclosed as well as a method for producing same. The hardfacing consists of a ceramic layer applied to a ferrous pump rotor body by way of plasma spraying and a top layer of metallic material having a lower hardness than the ceramic. The ceramic layer has a grainy surface with a plurality of peaks and intermediate depressions, the peaks being formed by ceramic grains at the surface of the ceramic layer. The thickness of the top layer is adjusted such that the depressions between the peaks of the ceramic layer are completely filled thereby providing the rotor with a ceramic hardfacing of significantly reduced surface roughness. In the process of the invention, the pump rotor, which may be provided with a molybdenum bonding layer, is plasma coated with the ceramic and the resulting ceramic layer is covered with the metallic material top layer.

Abstract: A downhole anchor for preventing rotational movement of a member within a well has a central tubular member, a slip housing and a drag assembly disposed about the tubular member. The slip housing carries at least two slip members, each slip member being mounted in a slot for slide-in positioning. This slip mounting feature facilitates assembly and refurbishment of the anchor. The slips are inwardly biased toward the tubular member by a spring acting between the slip members and the tubular member. The positioning of the spring in this way also facilitates assembly and refurbishment of the anchor and reduces stress damage to the slip housing.

Abstract: The present invention provides a method and apparatus for controlling the production rate of a rotary downhole pump to prevent well pump-off. The method includes the steps of operating the pump at a first speed less than a maximum rate of the pump until well fluid is produced at the wellhead. The operation is continued at the first speed until a first dynamic fluid level in the annulus between the production tubing and the wellbore or the well casing is stabilized. A first static load on the drivehead at the first dynamic fluid level is determined. The pump is then operated at a second speed higher than the first speed until the fluid level in the annulus is stabilized at a second dynamic fluid level. A second static load on the drivehead at the second dynamic fluid level is determined. A linear function of the load on the drivehead is determined as a function of the fluid level in the annulus.

Abstract: A downhole tool is described which can be used for injection of waste fluids which have been separated from desired production fluids into a disposal formation. When desired, the conduit for the waste fluids to the disposal formation can be closed off, thereby isolating the disposal formation from the production zone and providing access selectively to the production zone.

Abstract: A downhole tool is described can be used for handling waste fluids separated from desired hydrocarbon production fluids. The waste fluids are injected into a disposal formation. The tool is produced to avoid blockage of fluid flow passages and to reduce or eliminate the creation of a pressure differential across the tool. The tool is adaptable to be used with various sizes of pumps, to accommodate various pump intake filters and to conform to API tolerances. The downhole tool includes: an inner tube having a longitudinal bore, a seal disposed at the lower end of the longitudinal bore, an outer tube having an outer surface and being disposed about and spaced from the inner tube. An annulus is formed between the inner tube and the outer tube and is open at each end. A threaded connection is formed at the upper end of the outer tube to connect the outer tube to a tubing string such that the annulus opens into the tubing string's longitudinal bore.

Abstract: A method and an apparatus for producing fluid hydrocarbons through a single production tubing string from first and second zones which communicate with a hydrocarbon wellbore is disclosed. The apparatus includes a packer positioned in the wellbore for selectively preventing a flow of fluids through the wellbore from the first zone to the second zone, a production tubing string that extends through the wellbore and is in fluid communication through the packer with the second zone, and first and second pumps for displacing fluid through the production tubing string. The second pump displaces fluid from the lower zone into the production tubing string. A perforated joint is placed in the production tubing string between the second and the first pump. The second pump has a given displacement capacity at a given speed and is of a type that inhibits a flow of fluid in either direction through the pump when it is not pumping fluids from the second zone.