Long-stroke pumping unit

Patent metadata

Field	Value
Publication number	US-10196883-B2
Application number	US-201614992799-A
Country	US
Kind code	B2
Filing date	Jan 11, 2016
Priority date	Jan 9, 2015
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

A long-stroke pumping unit includes a tower; a counterweight assembly movable along the tower; a drum connected to an upper end of the tower and rotatable relative thereto. The unit also includes a belt having a first end connected to the counterweight assembly, extending over the drum, and having a second end connectable to a rod string. The unit further includes a prime mover for reciprocating the counterweight assembly along the tower; a sensor for detecting sudden acceleration of the counterweight assembly due to failure of the rod string; and a controller in communication with the sensor and operable to activate the braking or arrestor system in response to detection of the sudden acceleration. The unit further includes at least one of a braking system for halting free-fall of the counterweight assembly; and an arrestor system for absorbing kinetic energy of the falling counterweight assembly.

First claim

The invention claimed is:

1. A long-stroke pumping unit, comprising:
a tower;
a counterweight assembly movable along the tower;
a drum connected to an upper end of the tower and rotatable relative thereto;
a belt having a first end connected to the counterweight assembly, extending over the drum, and having a second end connectable to a rod string;
a prime mover for reciprocating the counterweight assembly along the tower;
a sensor for detecting acceleration of the counterweight assembly due to failure of the rod string;
a crown mounted atop the tower;
a shaft connected to the drum and rotatable relative to the crown;
a braking system for halting movement of the counterweight assembly; the braking system includes:
a disk disposed around and torsionally connected to the shaft;
a caliper mounted to the crown;
a piston disposed in a chamber formed in the caliper and movable relative to the caliper between an engaged position and a disengaged position;
a brake shoe connected to the piston; and
a brake pad mounted to the brake shoe, wherein the brake pad is clear of the disk in the disengaged position and pressed against the disk in the engaged position; and

a controller in communication with the sensor and operable to activate the braking system in response to detection of the acceleration.

2. The unit of claim 1 , wherein the sensor is an accelerometer mounted to the counterweight assembly.

3. A long-stroke pumping unit, comprising:
a tower;
a counterweight assembly movable along the tower;
a drum connected to an upper end of the tower and rotatable relative thereto;
a belt having a first end connected to the counterweight assembly, extending over the drum, and having a second end connectable to a rod string;
a prime mover for reciprocating the counterweight assembly along the tower;
a sensor for detecting acceleration of the counterweight assembly due to failure of the rod string;
a crown mounted atop the tower;
a shaft connected to the drum and rotatable relative to the crown;
a braking system for halting movement of the counterweight assembly, the braking system comprises:
a hood mounted to the crown;
a caliper mounted to the hood;
a piston disposed in a chamber formed in the caliper and movable relative to the caliper between an engaged position and a disengaged position; and
a brake shoe connected to the piston, and

the brake shoe is clear of the belt in the disengaged position and pressed against the belt in the engaged position; and
a controller in communication with the sensor and operable to activate the braking system in response to detection of the acceleration.

4. The unit of claim 3 , wherein:
the braking system further comprises a pad mounted to the brake shoe, and
the pad is pressed against the belt in the engaged position.

5. The unit of claim 3 , wherein the sensor is an accelerometer mounted to the counterweight assembly.

6. A long-stroke pumping unit, comprising:
a tower;
a counterweight assembly movable along the tower;
a drum connected to an upper end of the tower and rotatable relative thereto;
a belt having a first end connected to the counterweight assembly, extending over the drum, and having a second end connectable to a rod string;
a prime mover for reciprocating the counterweight assembly along the tower;
a sensor for detecting acceleration of the counterweight assembly due to failure of the rod string;
a crown mounted atop the tower;
a shaft connected to the drum and rotatable relative to the crown;
a braking system for halting movement of the counterweight assembly, the braking system comprises:
a rope having an end connected to a base of the tower and an end connected to the crown and extending through a rope brake;
the rope brake movable between an engaged position and a disengaged position and comprising:
a caliper mounted to the counterweight assembly; and
a pair of opposing brake shoes and pads; and

the brake pads are clear of the rope in the disengaged position and pressed against the rope in the engaged position; and

a controller in communication with the sensor and operable to activate the braking system in response to detection of the acceleration.

7. The unit of claim 6 , wherein:
one of the brake shoes and pads is connected to the caliper;
the other one of the brake shoes and pads is movable relative to the caliper; and
the rope brake further comprises:
a spring biasing the other one toward the engaged position; and
a trigger restraining the other one in the disengaged position.

8. The unit of claim 6 , wherein the sensor is an accelerometer mounted to the counterweight assembly.

9. A long-stroke pumping unit, comprising:
a tower;
a counterweight assembly movable along the tower;
a drum connected to an upper end of the tower and rotatable relative thereto;
a belt having a first end connected to the counterweight assembly, extending over the drum, and having a second end connectable to a rod string;
a prime mover for reciprocating the counterweight assembly along the tower;
a sensor for detecting acceleration of the counterweight assembly due to failure of the rod string;
a crown mounted atop the tower;
a shaft connected to the drum and rotatable relative to the crown;
a braking system for halting movement of the counterweight assembly, the braking system comprises:
a brake shoe hinged to the counterweight assembly and carrying a brake pad;
an actuator mounted to the counterweight assembly for swinging the brake shoe between an engaged position and a disengaged position; and
the brake pad is clear of the tower in the disengaged position and pressed against the tower in the engaged position; and

a controller in communication with the sensor and operable to activate the braking system in response to detection of the acceleration.

10. The unit of claim 9 , wherein the actuator comprises:
a housing mounted to the counterweight assembly;
a mandrel disposed in the housing and longitudinally movable relative thereto; and
a lever having a first end hinged to the brake shoe and a second end hinged to the mandrel.

11. The unit of claim 10 , wherein the actuator further comprises:
a spring disposed between the housing and the mandrel and biasing the mandrel toward the engaged position; and
a trigger connected to the housing and restraining the mandrel in the disengaged position.

12. The unit of claim 9 , wherein the sensor is an accelerometer mounted to the counterweight assembly.

13. A long-stroke pumping unit, comprising:
a tower;
a counterweight assembly movable along the tower;
a drum connected to an upper end of the tower and rotatable relative thereto;
a belt having a first end connected to the counterweight assembly, extending over the drum, and having a second end connectable to a rod string;
a prime mover for reciprocating the counterweight assembly along the tower;
a sensor for detecting acceleration of the counterweight assembly due to failure of the rod string;
an arrestor system for absorbing kinetic energy of the moving counterweight assembly, the arrestor system comprises a shock absorber or bladder disposed in a base of the tower; and
a controller in communication with the sensor and operable to activate the arrestor system in response to detection of the acceleration.

14. The unit of claim 13 , wherein:
the arrestor system comprises the shock absorber and a hydraulic circuit; and
the shock absorber comprises:
a cylinder having a rebound port and a damping port;
a pair of end caps connected to the cylinder;
damping fluid disposed in the cylinder;
a pis

Assignees

• Weatherford Tech Holdings Llc

Inventors

• Robison Clark E
• Thomas Benson
• Lane William C
• Yakimchuk Darius John
• Lembcke Jeffrey John
• Paulet Bryan A
• Cain Brandon M
• Christian Sean M
• Smith Paul L

Classifications

• F04B17/03

  driven by electric motors · CPC title

• F16F15/03

  using {magnetic or} electromagnetic means (F16F9/53, {F16F15/005} take precedence) · CPC title

• F04B47/14

  Counterbalancing · CPC title

• F16F15/027

  comprising control arrangements {(F16F15/0237 takes precedence)} · CPC title

• E21B43/126 Primary

  Adaptations of down-hole pump systems powered by drives outside the borehole, e.g. by a rotary or oscillating drive (powered by fluid E21B43/129) · CPC title