CPC E21B 43/26 (2013.01) [E21B 23/004 (2013.01); E21B 33/12 (2013.01); E21B 34/06 (2013.01)] | 17 Claims |
1. A plugging device for use in multistage fracturing a subterranean formation, the plugging device comprising:
a plug body having a distal end, a proximate end, and an outer surface;
a plurality of grooves disposed on the outer surface; and
an index sleeve movingly disposed on the outer surface, the index sleeve configured to engage the plurality of grooves;
wherein the proximate end comprises a shear ring, a seal element, and at least one backup ring disposed therearound,
wherein the index sleeve is set in an initial position before entering a first cluster of valves,
and wherein the index sleeve is configured to increment from the distal end toward the proximate end one groove of the plurality of grooves after leaving the first cluster of valves.
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