Patent ID: 8469109
Filing Date: 2013-06-25
Classification: E21B

Abstract:
1. An apparatus for plugging a wellbore completion, comprising: a dart comprising a first portion having a first outer diameter; and a second portion having a second outer diameter, wherein the second outer diameter is less than the first outer diameter; a ring disposed around the dart and slidable on the first and second portions of the dart, wherein the ring has an inner diameter that is variable between a first inner diameter when the ring is disposed around the first portion of the dart and a second inner diameter when the ring is disposed around the second portion of the dart; and a valve assembly having an inner diameter that is variable between a first inner diameter and a second inner diameter, wherein an outer diameter of the ring is less than the first inner diameter of the valve assembly when the ring is disposed around the first portion of the dart such that the dart is able to pass through the valve assembly, and wherein the outer diameter of the ring is greater than the second inner diameter of the valve assembly when the ring is disposed around the first portion of the dart such that the ring is configured to engage the valve assembly.