| 摘要 |
An apparatus and method for drilling a plurality of lateral wells from a main wellbore (10) including a junction joint (16) secured to the lower end of the lowermost casing string (14). The junction joint (16) includes an outer cylindrical housing (18) with a plurality of separate parallel guide tubes or tubular guide members (30A, 30B and 30C) secured to upper and lower plates (22 and 24) of the junction joint (16) and arranged to receive a pipe string. Entrance openings (26A, 26B, and 26C) are provided in upper plate (22) for the respective tubes (30A, 30B and 30C). A guide member (40) includes a small diameter alignment pin (54) and a pair of large diameter projecting pins (50). Upon alignment of guide member (40) with a selected tube (30A) by alignment of small diameter alignment pin (54) with an opening (38A) in upper plate (22), pins (50) are received within the upper ends of the non-selected tubes (30B and 30C) to close the non-selected tubes (30B and 30C). A drill string (76, FIG. 3) is received within the guide member (40) and selected tube (30A) for drilling a laterally extending wellbore. Additional lateral well bores are drilled in a similar manner through the remaining tubes (30B and 30C) after drilling of the first lateral wellbore.
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