| 摘要 |
A method and apparatus are provided for drilling multiple offshore wells from a single conductor casing string. A guide member is provided for securing to a standard casing string, and running downhole and setting within a lower section of the conductor string. The guide member includes multiple guide bores through which standard casing strings are run. A first one of the standard casing strings i secured into one of the multiple guide bores for lowering the guide member into the lower section of the conductor string. A multibore low pressure wellhead housing is mounted to the conductor string as the guide member is being lowered downhole within the conductor string. Once the guide member is set, the first one of the standard casing strings is released from the guide member and passed downward through the guide member for receiving a drill string and guiding the drill string in drilling a first one of the multiple offshore wells. Then, the first casing string is picked up, without being pulled from within the guide member, for joining with more casing and running further downhole through the guide member to case a first one of the multiple offshore wells. A second casing string is then lowered downhole and through the guide member for guiding the drill string. After a second one of the multiple offshore wells is drilled, the second casing string is then run further downhole, through the guide member, and used to case the second offshore well.
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