Directional drilling system and method for drilling precise offset wellbores from a main wellbore
AssigneeAnglo Suisse, Inc.
InventorsCharles G. Brunet, Gilles E. Labbee, Jay W. McGee
Life of this patent
Estimating the term…
Abstract
A directional drilling apparatus for drilling offset wellbores from a main borehole using a steering tool to orient a guidance tool body and wherein the tool body has a pair of angularly intersecting passageways including a first smaller passageway that communicates with a packer, and a second larger passageway that cradles a smaller drill string for drilling the offset boreholes and wherein the smaller drill string will not fit in the first smaller passageway.
Claims10
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, comprising:
- a) a tool body having a first, central longitudinally extending passageway that extends through the tool body;
- b) inflatable packer means for sealing the main wellbore below the first passageway;
- c) means in the first passageway for activating the packer so that it will inflate;
- d) the tool body having a second passageway that forms an acute angle with the first passageway, the second passageway having an entry portion that intersects the first passageway above the activating means;
- and
- e) the entry portion having means for routing the drill bit into the second passageway.
A method of drilling one or more offset wellbores from a first main wellbore comprising the step of:
- a) drilling the initial main wellbore;
- b) placing a first, larger drill string in the initial wellbore that has a tool body with first and second passageways therein forming an acute angle with respect to one another;
- c) orienting the radial position of the second passageway with respect to the initial, main wellbore using a steering tool;
- d) placing a second, smaller drill string in the main wellbore and inside the first drill string, the second drill string having a diameter larger than the first passageway;
- e) diverting the second drill string to the second passageway at a position upstream of first passageway;
- f) tracking the second passageway with the second drill string during drilling of an offset wellbore that forms an angle with the first borehole.
Dependencies are inferred from the claim text.