Question 3287 Deck General

The correct answer is D) drill collar. A drill collar is a heavy, thick-walled tube, usually made of steel, that is used between the drill pipe and the drill bit in the drill stem. The purpose of the drill collar is to add weight to the drill bit, which helps improve its performance and penetration into the ground or seabed. The other answer choices are incorrect because: A) heavy-walled drill pipe refers to the drill pipe itself, not the specialized tool used to weight the bit. B) a down-hole tool is a general term for any tool used in the drill stem, but does not specifically refer to the drill collar. C) a tool joint is the connection between sections of drill pipe, not the drill collar itself.