US 5,230,607 A · Method and apparatus for controlling the operation of a pumpjack

Abstract

A method and apparatus for vertically adjusting the stroke of the polished rod of a pumpjack during its operation in a producing well, while detecting abnormal conditions such as gas-off, pump seizure, sucker and separation, gas-lock pounding or fluid pounding. The method and apparatus involves a hydraulic or pneumatic cylinder interposed between the polished rod clamp and the carrier bar of the pumpjack. Abnormal conditions are detected by an electronic device incorporating a pressure transducer which senses fluid pressure changes in the hydraulic or pneumatic cylinder, converts the pressure changes into electrical voltages, and then determines if an abnormal condition is present. If an abnormal condition is sensed, the pumpjack can be stopped, and restarted automatically after a momentary interval in the event of gas-lock or fluid pounding, or manually after inspection by an operator in the event of a more serious condition.

Claims14

Dependent claims

An electronic fluid pump controller and electronic artificial lift motor controller for determining whether an emergency condition exits in a fluid pressure cylinder associated with an artificial lift apparatus used in an operating well, comprising:

a pumpjack operationally connected to the artificial lift apparatus;
a fluid pressure cylinder;
a fluid pressure transducer for measuring the fluid pressure within said fluid pressure cylinder, said fluid pressure transducer producing an electrical signal proportional to the fluid pressure within said cylinder;
a comparator unit for comparing the electrical signal produced by said transducer to a reference signal, said comparator unit producing an output signal for disabling said pumpjack when an emergency condition is sensed.

1 more element

A fluid pressure operated apparatus capable of allowing smooth controlled reciprocating movement of a polished rod therethrough, and a carrier bar operatively attached to said polished rod, included in an artificial life apparatus, operating on a fluid producing well, said apparatus comprising:

an outer piston casing having a top end and a bottom end, an inside surface and an outside surface;
a hollow shaft fixedly attached to said bottom end of said outer piston casing, said hollow shaft having a central through-bore for receiving said polished rod in smoothly slidable relation;
a slidably disposed fluid pressure piston disposed between said outer piston casing and said hollow shaft, said piston having an upper end and a lower end, an outside surface and an inside surface;
a removable load bearing end cap seated upon said end of said piston;
an air vent located near said top of said outer piston casing for venting to the atmosphere internal air pressure displaced within said casing when said piston travels toward said top end of said casing;
an outer casing piston surrounding said hollow shaft and sealed by said end cap, said piston slidably disposed within said cylinder;
a packing assembly, including a first seal seated in a machined groove located on the lower outside end of said piston, and a second seal seated in a machined groove located on the lower inside end of said piston, whereby said first seal forms a fluid tight closure between the piston and the inside surface of said piston casing and said second seal forms a fluid tight closure between the piston and said hollow piston;
a fluid pressure port leading through said outer casing, said port serving as an outlet port;
whereby, when pressurized fluid is fed into said piston casing, said piston travels to bear against said end cap so as to contact said polished rod clamp thereby urging said polished rod a distance proportional to the length of the travel of said piston.

6 more elements

Dependencies are inferred from the claim text.

Method and apparatus for controlling the operation of a pumpjack

Life of this patent

Method and apparatus for controlling the operation of a pumpjack

Life of this patent

Abstract

Claims14