BIT-STABILIZED COMBINATION CORING AND DRILLING SYSTEM

摘要

A core barrel having an inner tube for coring and, alternately, a center pl ug assembly for closing the throat of the core bit at the bottom of the assembl y for drilling in lieu of coring. The inner tube assembly and plug assembly are disposable and retrievable through the drill string on a wireline using an overshot. Th e core bit is of a stabilized, preferably anti-whirl, design and may be a low-invasion core bit used in cooperation with a low-invasion coring shoe. A logging tool and data transmission assembly may be incorporated in the plug assembly for logging while drilling.