Interference-seal plunger for an artificial lift system

Abstract

A plunger for an artificial lift system and embodiment of the plunger includes a solid body adapted to travel within a production string positioned in a wellbore. At least one sealing ring connected about the body. The at least one sealing ring having an inner surface, an outer surface, a width and a thickness. The width is sufficient such that when the body is disposed in the production string the outer surface contacts and substantially forms a seal between the body and an inner wall of the production string. The at least one sealing ring having an outside diameter greater than the inner diameter of the production tubing within which the body is adapted to travel such that when the body is disposed within the production string an interference fit causes the sealing rings to roll-form into a constricted shape and diameter that exerts the sealing contact with the production string.

Description

FIELD OF THE INVENTION [0001] The present invention relates in general to producing fluids from a well and more specifically to an interference-seal plunger for a plunger lift system. BACKGROUND [0002] In the life of most wells the reservoir pressure decreases over time resulting in the failure of the well to produce fluids utilizing the formation pressure solely. As the formation pressure decreases, the well tends to fill up with liquids, such as oil and water, which inhibits the flow of gas into the wellbore and may prevent the production of liquids. It is common to remove this accumulation of liquid by artificial lift systems such as plunger lift, gas lift, pump lifting and surfactant lift wherein the liquid column is blown out of the well utilizing the reaction between surfactants and the liquid. [0003] One method of producing fluids from a declining well having gas production is by utilizing a plunger lift system. A well is shut-in allowing a plunger to fall through the fluid c...

AI Technical Summary

Benefits of technology

[0010] In another embodiment the plunger may include a solid body adapted to travel within a production string positioned in a wellbore. At least one sealing ring is connected about the body. The at least one sealing ring having an inner surface, an outer surface, a width and a thickness. The width is sufficient such that when the body is disposed in the production string, the outer surface contacts and substantially forms a seal between the body and an inner wall of the production string. The at least one sealing ring has a width to thickness ratio within a range from about 0.02 to 0.2 wherein when the body is disposed within the production string, the sealing ring assumes a shape such that the sealing ring enhances movement of the body over the drag from the sealing contact.

Problems solved by technology

The sealing rings may have an outside diameter greater than the inner diameter of the production tubing within which the body is adapted to travel such that when the body is disposed within the production string, an interference fit causes the sealing rings to roll-form into a constricted shape and diameter that exerts the sealing contact with the production string.

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