What is the primary purpose of an overshot in drilling operations?

An overshot is specifically designed to retrieve lost objects from the wellbore during drilling operations. Its primary purpose is to enable the recovery of tools, bits, or other equipment that have become stuck or dropped in the well. The overshot is equipped with a catch mechanism that allows it to grasp and lift these objects back to the surface, making it an essential tool for maintaining operational efficiency and minimizing downtime caused by lost components in the well.

In drilling scenarios, the need for effective retrieval tools like the overshot is significant, as losing equipment can lead to costly delays and complications in the drilling process. Other options mentioned do not align with the function of an overshot, as they serve different roles in drilling operations. For instance, measuring water flow pertains to flow meters or similar devices, while drilling into hard rock requires specialized bits and techniques rather than a tool specifically designed for retrieval. A support structure for the drilling rig involves different equipment entirely focused on stability and safety rather than object retrieval in the wellbore.