Patent ID: 9683430
Date: 2017-06-20
CPC Classifications: E21B

Claim:
1. A plunger for use in a downhole well, comprising: a body having a bore formed axially-therethrough, wherein an inner surface of the body that defines the bore forms a seat; a stop extending at least partially laterally through the bore; and an obstructing member positioned within the bore and configured to move axially within the bore between the seat and the stop, wherein the obstructing member is configured to prevent fluid flow through the bore in one axial direction when in contact with seat, and to allow fluid flow through the bore in an opposite axial direction when in contact with the obstructing member as the plunger descends in the well, wherein the body comprises a plurality of circumferentially-offset helical grooves defined in an outer surface of the body, and wherein the seat is axially-aligned with the helical grooves.