DOWNHOLE BALL DROPPING SYSTEMS AND METHODS WITH REDUNDANT BALL DROPPING CAPABILITY

摘要

A downhole ball dropping system operable to be positioned in a well. The system includes a tool string having a flow path. First and second ball dropper assemblies are interconnected in the tool string. The first ball dropper assembly releasably retains a first ball and the second ball dropper assembly releasably retains a second ball. A sensor is operable to detect deployment of the first ball and is operable to generate a signal to prevent release of the second ball from the second ball dropper assembly.