A hydraulic tool includes a stator and a rotor rotatably disposed within the stator. At least one of at least an inner portion of the stator and at least an outer portion of the rotor includes an insert comprising a hard material. A method of forming a hydraulic tool includes attaching at least one insert comprising a hard material to a surface of a stator or a surface of a rotor. A downhole motor or pump includes a stator and a rotor. The stator includes at least one insert comprising a hard material disposed over at least a portion of an interior surface thereof and a matrix material at least partially surrounding the at least one insert. The rotor includes at least one insert disposed over at least a portion of an exterior surface thereof and a matrix material at least partially surrounding the at least one insert.

A method of lining an inner surface of a tubular with a polymer, includes positioning a polymer injecting head within the tubular, forming an annular space between the injecting head and an inner surface of the tubular, injecting polymer through the injecting head into the annular space, and moving the polymer injecting head longitudinally relative to the tubular while injecting polymer.

A method of lining an inner surface of a tubular with a polymer, includes positioning a polymer injecting head within the tubular, forming an annular space between the injecting head and an inner surface of the tubular, injecting polymer through the injecting head into the annular space, and moving the polymer injecting head longitudinally relative to the tubular while injecting polymer.

Rotary positive displacement machines based on trochoidal geometry, that comprise a helical rotor that undergoes planetary motion within a helical stator are described. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides structural and/or operational advantages in the rotary machine.

A stator for a helical gear device includes a first section having first helically convoluted chamber with a set of radially inwardly extending lobes and a second section adjacent to the first section. The second section includes a stack of cutter disks. Each cutter disk includes a front surface, a rear surface, an interior surface defining a central opening extending from the front surface to the rear surface, a forward cutting edge, and a rearward cutting edge. The interior surface forms a same number of lobes for the central opening as the set of radially inwardly extending lobes in the first section. Each cutter disk is aligned along a common centerline, and each cutter disk is rotated slightly relative to each other to form a second helically convoluted chamber with a same pitch as the first helically convoluted chamber. The second helically convoluted chamber exposes, to materials passing through, portions of the forward cutting edge or the rearward cutting edge of each cutter disk.

A method of lining an inner surface of a tubular with a polymer, includes positioning a polymer injecting head within the tubular, forming an annular space between the injecting head and an inner surface of the tubular, injecting polymer through the injecting head into the annular space, and moving the polymer injecting head longitudinally relative to the tubular while injecting polymer.

A method of lining an inner surface of a tubular with a polymer, includes positioning a polymer injecting head within the tubular, forming an annular space between the injecting head and an inner surface of the tubular, injecting polymer through the injecting head into the annular space, and moving the polymer injecting head longitudinally relative to the tubular while injecting polymer.

A moving or progressive cavity motor or pump is disclosed, the motor including a rotor and a stator, the stator having one or more inserts or gearing sections to limit a lateral movement of the rotor relative to the stator. In some embodiments, the motor or pump may include a rotor and a stator, the stator including: a first, helicoidal, section comprising a compliant material having a first compressibility; a second section, helicoidal, non-helicoidal, or combination thereof, having a second compressibility, wherein the second compressibility is less than the first compressibility.

A moving or progressive cavity motor or pump is disclosed, the motor including a rotor and a stator, the stator having one or more inserts or gearing sections to limit a lateral movement of the rotor relative to the stator. In some embodiments, the motor or pump may include a rotor and a stator, the stator including: a first, helicoidal, section comprising a compliant material having a first compressibility; a second section, helicoidal, non-helicoidal, or combination thereof, having a second compressibility, wherein the second compressibility is less than the first compressibility.

A stator compound including an acrylonitrile butadiene isoprene rubber (NBIR) terpolymer elastomeric base.