| 摘要 |
A hydraulic underreamer for enlarging a wellbore (18) includes improved packer (20), cutting (24), jet pump (26), and mill (28) sections. T he packer section (20) is designed to minimize wear on its sealing elements (36, 38), the cutting (24) and jet pump (26) sections are designed to minimize pressure requiremen ts and optimize hydraulic efficiency, and the mill section (28) has a removable center assembly which allows effective well control when pulling the underreamer ou t of a "live" well filled with gas, such as methane.
|
