| 摘要 |
A duct assembly (13) for drilling supplementary boreholes (17) comprises a plurality of duct body sections (7), whipstocks (5), and separators (8) forming multiple channel segments (7a, b) within the duct body sections (7). In one embodiment, the separators (8) are plates that substantially divide each duct body section (7) into two semicircular channel segments (7a, b) and align adjoining duct body sections (7), allowing the drilling of supplementary boreholes (17) to be reliably directed without whipstock repositioning.
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