Directional drilling system and method for drilling precise offset wellbores from a main wellbore
This patent describes a directional drilling apparatus for deflecting a drill bit to drill an offset borehole from the central axial path of a main wellbore of vertical, horizontal, or slanted orientation. It comprises a tool body; inflatable packer means for sealing the main wellbore below the first passageway; means in the first passageway for activating the packer so that it will inflate; the tool body having a second passageway that forms an acute angle with the first passageway; and an entry portion having means for routing the drill bit into the second passageway. This patent also describes a method of drilling one or more offset wellbores from a first main wellbore. It comprises drilling the initial main wellbore; placing a first, larger drill string in the initial wellbore that has a tool body with first and second passageways therein; orienting the radial position of the second passageway with respect to the initial, main wellbore using a steering tool; placing a second, smaller drill string in the main wellbore and inside the first drill string; diverting the second drill string to the second passageway at a position upstream of first passageway; tracking the second passageway with the second drill string during drilling of an offset wellbore that forms an angle with the first borehole.
- Assignee:
- Anglo Suisse, Inc., Houston, TX (United States)
- Patent Number(s):
- US 5115872; A
- Application Number:
- PPN: US 7-599756
- OSTI ID:
- 7310560
- Resource Relation:
- Patent File Date: 19 Oct 1990
- Country of Publication:
- United States
- Language:
- English
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