| 摘要 |
Drilling systems and methods for enlarging a borehole that include at least one expandable reamer and at least one expandable stabilizer axially spaced therefrom in a tubular string, such as a drill string, the at least one expandable reamer and the at least one expandable stabilizer being independently actuatable by different-sized actuation devices. A relatively lower tool is actuatable by a smaller actuation device, such as a drop ball, which passes through a relatively higher tool in the drill string without triggering the higher tool. |
