LONG-STROKE PUMPING UNIT

摘要

A sucker rod lifting system generally includes a surface drive mechanism, a sucker rod string, and a downhole pump. One such surface drive mechanism is known as a long-stroke pumping unit. The long-stroke pumping unit includes a counterweight which travels along a tower during operation thereof. Should the sucker rod string fail, there is a potential that the counterweight assembly will free fall and damage various parts of the pumping unit as it crashes under the force of gravity. The sudden acceleration of the counterweight assembly may not be controllable using the existing long-stroke pumping unit. The present disclosure generally relates to a braking system or an arrestor system for the counterweight assembly of a long-stroke pumping unit.