An exemplary pump jack system (10) is operable to cause well liquid to be pumped to the surface by a subsurface well pump (29). The exemplary system includes a driver (42) that is in rotatable connection with a pump/motor (48). The pump/motor is a rotary type variable output positive displacement pump/motor that delivers working liquid at a selectively variable flow rate in closed liquid connection to a motor/pump (38). The exemplary motor/pump includes a rotatable output coupler (40) that is in operative connection with a gearbox (34) which causes the pump jack to undergo reciprocating motion. The motor/pump is a rotary type positive displacement motor/pump that is in closed liquid connection with the pump/motor liquid inlet of the pump motor. The pump/motor is operable to deliver working liquid flow therefrom to drive the motor/pump at a selectively variable speed while the driver operates at a generally constant rotational speed. Return force which acts on the motor/pump during at least a portion of the pump jack cycle is operative to cause the motor/pump to urge working liquid toward the pump/motor which assists the driver in pump/motor operation.

This disclosure relates to a direct drive pumping unit having a reciprocator for reciprocating a sucker rod string and a sensor for detecting position of a polished rod. The reciprocator includes a tower for surrounding a wellhead. The polished rod is connectable to the sucker rod string and has an inner thread open to a top thereof and extends along at least most of a length thereof. A screw shaft extends into the polished rod and interacts with the inner thread. A motor is mounted to the tower, torsionally connected to the screw shaft, and operable to rotate the screw shaft relative to the polished rod.

This disclosure relates to a direct drive pumping unit having a reciprocator for reciprocating a sucker rod string and a sensor for detecting position of a polished rod. The reciprocator includes a tower for surrounding a wellhead. The polished rod is connectable to the sucker rod string and has an inner thread open to a top thereof and extends along at least most of a length thereof. A screw shaft extends into the polished rod and interacts with the inner thread. A motor is mounted to the tower, torsionally connected to the screw shaft, and operable to rotate the screw shaft relative to the polished rod.

Pumping machine (650, 750) comprising: at least two tubular elements (651, 751) containing pressurized gas and extending vertically in parallel and interconnected between them by means of a connecting element (652, 752); andan electromechanical lifting system (600, 700) comprising a first cylinder (601, 701), interconnected to the tubular elements (651, 751) and comprising a substance compressible by a piston (601b, 701b); and a screw (602, 702) with a vertical axis Y coinciding with the axis of the pumping machine (650, 750). The screw (602, 702) is inserted inside a second thrust cylinder (658, 758), connected in sliding manner inside the first cylinder (601, 701), and has a first end (602b, 702b) fixed to the connecting element (652, 752) and a second end (602a, 702a) configured for sliding inside the thrust cylinder (658, 758) and overlying a chamber (605, 705) comprising lubrication and cooling oil overlying the piston (601b, 701b).

Pumping machine (650, 750) comprising: at least two tubular elements (651, 751) containing pressurized gas and extending vertically in parallel and interconnected between them by means of a connecting element (652, 752); andan electromechanical lifting system (600, 700) comprising a first cylinder (601, 701), interconnected to the tubular elements (651, 751) and comprising a substance compressible by a piston (601b, 701b); and a screw (602, 702) with a vertical axis Y coinciding with the axis of the pumping machine (650, 750). The screw (602, 702) is inserted inside a second thrust cylinder (658, 758), connected in sliding manner inside the first cylinder (601, 701), and has a first end (602b, 702b) fixed to the connecting element (652, 752) and a second end (602a, 702a) configured for sliding inside the thrust cylinder (658, 758) and overlying a chamber (605, 705) comprising lubrication and cooling oil overlying the piston (601b, 701b).

A long-stroke pumping unit includes a tower, a counterweight assembly movable along the tower, and a crown mounted atop the tower. A sprocket is supported by the crown and rotatable relative thereto. The counterweight is coupled to a belt. The pumping unit further includes a motor having a stator mounted to the crown and a rotor torsionally connected to the sprocket. A sensor is used to detect a position of the counterweight assembly. The pumping unit may include a dynamic control system for controlling a speed of a motor.

A long-stroke pumping unit includes a tower, a counterweight assembly movable along the tower, and a crown mounted atop the tower. A sprocket is supported by the crown and rotatable relative thereto. The counterweight is coupled to a belt. The pumping unit further includes a motor having a stator mounted to the crown and a rotor torsionally connected to the sprocket. A sensor is used to detect a position of the counterweight assembly. The pumping unit may include a dynamic control system for controlling a speed of a motor.

Pumps are provided, more particularly piston type pumps having increased energy efficiency, systems incorporating such piston type pumps, and methods of operating piston type pumps. The pumps are suitable for pumping of oil from an oil well or for pumping other liquids such as ground water, subterranean liquids, brackish water, sea water, waste water, cooling water, gas, coolants, and the like.

A delivery device having a connecting rod, and a method for controlling a delivery device having a connecting rod and at least one balance weight, includes a part that is permanently connected to a shaft, on which part a pivot bearing is situated, by which the first end region of the connecting rod is accommodated by the part, in particular such that the connecting rod is able to be driven in eccentric manner, balance weights being situated on the part so as to be displaceable by a first drive, a first computer being provided on the part, which controls the displacement of the balance weights.

A delivery device having a connecting rod, and a method for controlling a delivery device having a connecting rod and at least one balance weight, includes a part that is permanently connected to a shaft, on which part a pivot bearing is situated, by which the first end region of the connecting rod is accommodated by the part, in particular such that the connecting rod is able to be driven in eccentric manner, balance weights being situated on the part so as to be displaceable by a first drive, a first computer being provided on the part, which controls the displacement of the balance weights.