System And Apparatus For Locating And Avoiding An Underground Obstacle
First Claim
1. An apparatus for redirecting a drill string from an existing borehole, the apparatus comprising:
- a housing supported on the drill string;
a drill bit operatively connected to the housing; and
a redirection assembly adapted to force the drill bit into a side wall of an existing borehole at a point remote from an end of the existing borehole.
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Accused Products
Abstract
A method and apparatus for detecting and avoiding an underground object during a horizontal directional drilling operation. The apparatus comprises a boring tool with a ground penetrating radar detection system. The boring tool is operatively connected to a drill string and advanced through the earth to create a borehole. The radar detection system includes at least one transmitter, at least one detector, and a processor. The transmitter is located on a surface of the boring tool and is adapted to transmit electromagnetic waves. At least one detector is located on the surface of the boring tool, and detects the electromagnetic waves reflected by underground objects. The processor determines the location of the underground object from characteristics of the reflected waves. Using this information, the drill string may be pulled back up the borehole or redirected to avoid the object. The boring tool may be caused to breakout of the existing borehole using a pivoting boring tool. Alternatively, a shoe protruding from the boring tool may be engaged to push the boring tool into an opposite wall of the borehole.
47 Citations
14 Claims
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1. An apparatus for redirecting a drill string from an existing borehole, the apparatus comprising:
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a housing supported on the drill string; a drill bit operatively connected to the housing; and a redirection assembly adapted to force the drill bit into a side wall of an existing borehole at a point remote from an end of the existing borehole. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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- 9. The apparatus of claim 21 wherein the redirection assembly comprises a rotation assembly supported by the housing, wherein the rotation assembly is adapted to pivot the drill bit relative to the housing.
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12. A method for redirecting a drill string from an existing borehole, the method comprising:
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detecting an object in a projected path of a drill bit on an end of a drill string; retracting the drill string a predetermined distance in the borehole such that the drill bit is at a position remote from an end of the borehole; pivoting the drill bit at the end of the drill string such that the drill bit is forced into a side wall of the borehole; and advancing the drill string without rotation so the drill bit exits the borehole through the side wall of the borehole. - View Dependent Claims (13, 14)
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Specification