What kind of device is used for isolating sections of a wellbore?

A packer is a device specifically designed for isolating sections of a wellbore. It is placed in the well to create a seal between the casing and the borehole wall, effectively allowing for the separation of different zones within the well. This isolation is crucial for various operations, such as reducing fluid movement between strata, allowing for the completion of specific sections, and facilitating testing or treatment of particular zones without interference from adjacent formations.

In contrast, casing serves as lining for the wellbore, providing structural integrity and protecting it from external elements, but it does not independently isolate sections. A drill bit is used for cutting into the formation and creating the wellbore, while a blowout preventer is a safety device designed to control pressure and prevent the uncontrolled release of fluids during drilling operations. These other components serve different primary functions and do not provide the isolation capabilities that a packer does.