| 摘要 |
A method of creating a second wellbore section (19), penetrating a subterranean earth formation having at least one gas-bearing zone (3), from a selected location in an existing first wellbore section (1) using a remotely-controlled drilling device (13) under underbalanced drilling conditions, which method comprises:
(a) arranging the remotely-controlled drilling device (13) at the selected location in the first wellbore section (1), in or below a production tube (6),
(b) operating the remotely-controlled drilling device (13) to drill the second wellbore section (19),
(c) controlling the flow of gas produced from the gas-bearing formation through the production tube (6) to the wellhead (8),
(d) using a fluid stream comprising at least a portion of produced gas to transport the drill cuttings resulting from the drilling operation to the wellhead (8) and
(e) controlling the pressure in the production tube (6) such that the linear velocity of the gas does not fall below 1 m/s and does not exceed 75 m/s.
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