A multi-mode subterranean energy system and a related multi-mode subterranean energy production method are disclosed. The system comprises subterranean tunnels (2, 3, 8, 9, 14) connecting an upper reservoir of water (1), an underground cavity (10) and a subterranean recipient (15), a turbine/pump unit (4), and water flow control means (5, 6, 7). The system optionally can be operated in four modes.

The present invention is a reversible pump-turbine installation positioned in a vertical borehole instead of in a conventional underground powerhouse or deep concrete powerhouse. The required plant cavitation coefficient may be achieved by simply boring a vertical borehole to the required depth rather than routing the water flow to and from a deeply buried powerhouse. A pneumatically controlled pressure relief valve may be incorporated into this invention.

A fluid-powered linear motor with rotary pistons is disclosed. An application is for a downhole motor but it could be used in other applications. Rotational pistons provide increased torque generation as the torque generated is proportional to motor length. Since downhole drills are long (generally up to a maximum length of 30 ft.), a high-torque motor can be produced using this method. A pressurized fluid is used to drive the piston assemblies to produce bit shaft power. This concept employs rotary pistons and a mechanical rectifier to convert the rotational reciprocation produced by a reciprocating rotational piston into continuous rotary motion. Integration of synthetic diamond bearing assemblies into the motor allows for reduced friction and abrasive drilling fluid compatibility.

A method for calibrating a unit controller with a managing process determining a position of a decoupler mechanism on the pumping unit. The managing process can calibrate the unit controller with a dual pump mode in response to determining the decoupler mechanism is in a coupled position. The managing process can calibrate the unit controller with a single pump mode in response to determining the decoupler mechanism is in a decoupled position with the pumping unit operating with the first fluid end coupled to the power end and the second fluid end decoupled from the power end. The system controller can pump a wellbore treatment fluid in accordance with the pumping unit in i) the dual pump mode or ii) the single pump mode.

A method for calibrating a unit controller with a managing process determining a position of a decoupler mechanism on the pumping unit. The managing process can calibrate the unit controller with a dual pump mode in response to determining the decoupler mechanism is in a coupled position. The managing process can calibrate the unit controller with a single pump mode in response to determining the decoupler mechanism is in a decoupled position with the pumping unit operating with the first fluid end coupled to the power end and the second fluid end decoupled from the power end. The system controller can pump a wellbore treatment fluid in accordance with the pumping unit in i) the dual pump mode or ii) the single pump mode.

Provided is a wellbore tractor and method for operating a well system. The wellbore tractor, in one aspect, includes a base member, a hydraulically powered drive section coupled to the base member, and one or more turbines coupled to the hydraulically powered drive section for powering the hydraulically powered drive section based upon fluid flow across the one or more turbines. The wellbore tractor, according to this aspect, further includes one or more wellbore engaging devices radially extending from the hydraulically powered drive section, the one or more wellbore engaging devices contactable with a surface of a wellbore for displacing the wellbore tractor axially downhole.

Provided is a wellbore tractor and method for operating a well system. The wellbore tractor, in one aspect, includes a base member, a hydraulically powered drive section coupled to the base member, and one or more turbines coupled to the hydraulically powered drive section for powering the hydraulically powered drive section based upon fluid flow across the one or more turbines. The wellbore tractor, according to this aspect, further includes one or more wellbore engaging devices radially extending from the hydraulically powered drive section, the one or more wellbore engaging devices contactable with a surface of a wellbore for displacing the wellbore tractor axially downhole.

A downhole system includes a drill string having a drilling fluid flow channel and at least one turbine alternator deployed in the flow channel. The turbine alternator is configured to convert flowing drilling fluid to electrical power. A voltage bus is configured to receive electrical power from the turbine alternator and at least one electrical motor is configured to receive electrical power from the voltage bus. An electronic controller is configured to provide active control of the turbine alternator via processing a desired speed of the electrical motor to generate a desired torque current and feeding the desired torque current forward to the turbine alternator. The turbine alternator is responsive to the desired torque current such that it modifies the electrical power provided to the voltage bus in response to the desired torque.

The present disclosure relates to a friction reduction tool having a housing for connecting the friction reduction tool to a drill string or coiled tubing; a force converter within the housing and having a stator, a helical rotor, and a rotational cavity passageway for conveying drilling fluid between the stator and the helical rotor; and a valve assembly; wherein the helical rotor has a bore which extends through the helical rotor and which defines an alternative passageway for the drilling fluid; and wherein the rotational cavity passageway and the alternative passageway are in fluidic communication with the valve assembly.

A downhole power generation system is disclosed, which includes a turbine generator system. The turbine generator system includes a turbine, a generator coupled with the turbine and having an AC-DC rectifier, and an optimized power control unit. The turbine is driven by flow of a downhole fluid to rotate. The generator converts rotational energy from the turbine to electrical energy and outputting a direct current voltage. The turbine generator system is coupled to a load via the optimized power control unit. The optimized power control unit controls to regulate an output voltage of the generator and provides a regulated output voltage to the load so that the turbine generator system has an optimized power output. An optimized power control method for a downhole power generation system is also disclosed.