In contrast to older shale gas plays, such as the Antrim Shale, the New Albany Shale, and the Ohio Shale, the Barnett Shale completions are much deeper (up to 8,000 feet). The thickness of the Barnett varies from 100 to 1,000 feet (300 m), but most economic wells are located where the shale is between 300 and 600 feet (180 m) thick. The success of the Barnett has spurred exploration of other deep shales.