Long-stroke pumping unit

Patent metadata

Field	Value
Publication number	US-2016245276-A1
Application number	US-201615051060-A
Country	US
Kind code	A1
Filing date	Feb 23, 2016
Priority date	Feb 23, 2015
Publication date	Aug 25, 2016
Grant date	—

Abstract

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

First claim

1 . A pumping unit, comprising:
a prime mover for reciprocating a rod string; and a dynamic control system for controlling a speed of the prime mover and comprising:
a load cell for measuring force exerted on the rod string;
a sensor for detecting position of the rod string;
an accelerometer for measuring vibration of the rod string or of a production string;
a meter for measuring power consumed by the prime mover; and
a controller operable to:
determine position of and load on a downhole pump connected to the rod string and the production string;
determine acceptability of two or more parameters of the pumping unit;
select a prime objective based on a hierarchy of the parameters and the acceptability of the parameters; and
determine an upstroke speed, a downstroke speed, and turnaround accelerations and decelerations for the prime objective.

2 . The unit of claim 1 , wherein the accelerometer is integrated within the load cell for measuring the vibration of the rod string.

3 . The unit of claim 1 , wherein the accelerometer is a dual axis microelectromechanical system.

4 . The unit of claim 1 , further comprising:
a tower; a counterweight assembly movable along the tower; a crown mounted atop the tower; a belt having a first end connected to the counterweight assembly and having a second end connectable to the rod string, wherein the sensor is operable to detect a position of the rod string by detecting a position of the counterweight assembly.

5 . The unit of claim 4 , wherein the sensor is an ultrasonic rangefinder comprising a long range transducer and a short range transducer.

6 . The unit of claim 4 , wherein the sensor is a linear variable differential transformer (LVDT) comprising:
a string connected to the counterweight assembly and wound onto a spool; a screw shaft engaged with a thread of the spool; an LVDT core mounted to the screw shaft; and an LVDT body at least partially receiving the LVDT core.

7 . The unit of claim 6 , wherein the controller is further operable to monitor for failure of the rod string or load belt and control descent of the counterweight assembly in response to detection of the failure.

8 . The unit of claim 1 , wherein the controller is further operable to monitor for failure or imminent failure of the pumping unit and to:
a. shut down the pumping unit in response to detection of the failure or imminent failure, or b. operate the pumping unit using an emergency hierarchy and emergency acceptability values in response to detection of the failure or imminent failure.

9 . A long-stroke pumping unit, comprising:
a tower; a counterweight assembly movable along the tower; a crown mounted atop the tower; a sprocket supported by the crown and rotatable relative thereto; a belt having a first end connected to the counterweight assembly, extending over and meshing with the sprocket, and having a second end connectable to a rod string; a motor having a stator mounted to the crown and a rotor torsionally connected to the sprocket; and a sensor for detecting position of the counterweight assembly.

10 . The unit of claim 9 ,
further comprising a second sprocket and a drum, each supported by the crown and rotatable relative thereto, wherein the sprockets straddle the drum.

11 . The unit of claim 10 , wherein the belt comprises:
a body made from an elastomer or elastomeric copolymer; a mesh disposed in the body and extending along a length thereof and across a width thereof; and two rows of sprocket holes, each row formed adjacent to and along a respective edge of the belt and each hole formed through the body and the mesh.

12 . The unit of claim 10 , wherein the belt comprises:
a body made from an elastomer or elastomeric copolymer; a ply of cords disposed in the body, each cord extending across a width thereof; two rows of sprocket holes, each row formed adjacent to and along a respective edge of the belt and each hole formed through the body and the plies; and two pairs of ropes disposed in the body, each rope extending along a length thereof and each pair straddling the sprocket holes.

13 . The unit of claim 9 , wherein the belt comprises:
a body made from an elastomer or elastomeric copolymer; alternating teeth and flats, each tooth and each flat formed across an inner surface of the body; and a ply of cords disposed in the body adjacent to the inner surface, each cord extending along a length thereof.

14 . The unit of claim 9 , further comprising a gear box torsionally connecting the rotor to the sprocket.

15 . The unit of claim 9 , wherein the motor is an electric three phase motor.

16 . The unit of claim 15 , further comprising:
a variable speed motor driver in electrical communication with the motor; and a controller in data communication with the motor driver and the sensor and operable to control speed thereof.

17 . The unit of claim 16 , wherein the controller is further operable to monitor the sensor for failure of the rod string and instruct the motor driver to control descent of the counterweight assembly in response to detection of the failure.

18 . A long-stroke pumping unit, comprising:
a tower; a crown mounted atop the tower; a spool supported by the crown and rotatable relative thereto; a belt having an upper end mounted to the spool, wrapped around the spool, and having a lower end connectable to a rod string; a motor having a stator mounted to the crown and a rotor torsionally connected to the spool; and a torsion spring having one end connected to the crown and the other end connected to the spool for biasing the spool toward wrapping of the belt thereon.

19 . The unit of claim 18 , further comprising a gear box torsionally connecting the rotor to the spool.

20 . The unit of claim 18 , further comprising:
a sensor for detecting position of the lower end of the belt a variable speed motor driver in electrical communication with the motor; and a controller in data communication with the motor driver and the sensor and operable to control speed thereof.

Assignees

• Weatherford Tech Holdings Llc

Inventors

• Robison Clark E
• Lembcke Jeffrey John
• Pons Victoria M
• Hall William Kevin
• Stachowiak Jr John Edward
• Thomas Benson
• Christian Sean M
• Paulet Bryan A
• Basler Hermann

Classifications

• F04B49/20 Primary

  by changing the driving speed · CPC title

• E21B47/009

  Monitoring of walking-beam pump systems · CPC title

• F04B47/14

  Counterbalancing · CPC title

• E21B43/126

  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

• F04B47/026

  Pull rods, full rod component parts · CPC title