EARTH BORING DEVICE AND METHOD OF USE

摘要

A borehole tool for drilling in a formation is disclosed. The tool is of the type that incorporates a sphere for deploying cutting elements for hydraulically expanding the same for borehole reaming or enlargement during drilling. The tool conveniently includes a reset function where the cutting elements can be reset to a retracted position within the cutter housing. Advantageously the reset of the cutter elements is achievable by simply removing a cutting bit at the end of drill string and inserting the reset member in the form of a elongate rod through the end of the drill string to urge the sphere or ball back to the top of the drill string for retrieval and resetting the movable member which allows for fluid flow redirection within the cutter housing. The reset function can be achieved on site thus avoiding significant expenses and downtime typically associated with systems that cannot be reset onsite.