Drill string inground isolator in an MWD system and associated method
First Claim
1. An apparatus for use in combination with a drill string that is electrically conductive and extends from an inground distal end, that includes an inground tool, to a drill rig, said apparatus comprising:
- a first group of electrical isolators and a second group of electrical isolators; and
a housing that defines a through passage along a length thereof and said housing is configured to support the first group and the second group in a spaced apart relationship along said length and surrounding the through passage such that, responsive to the drill rig pushing on the drill string, a first one of the first and second groups is subject to a first compressive force and responsive to the drill rig pulling on the drill string the other one of the first and second groups is subject to a second compressive force without subjecting either of the first and second groups to a tension force during said pushing and pulling by the drill rig to form an electrically isolating break in the drill string.
1 Assignment
0 Petitions
Accused Products
Abstract
An inground isolator and associated method can provide an electrically isolated break in a drill string using electrical insulating members/isolators that are supported by a housing. During drill string operations, the isolators are subject only compressive forces responsive to both extension (pushing) and retraction (pulling) by the drill string. The isolators can be formed from an electrically insulating material such as a ceramic material. An interchangeable inground tool system is described which integrally serves to provide an electrically isolating gap in the drill string.
54 Citations
113 Claims
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1. An apparatus for use in combination with a drill string that is electrically conductive and extends from an inground distal end, that includes an inground tool, to a drill rig, said apparatus comprising:
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a first group of electrical isolators and a second group of electrical isolators; and a housing that defines a through passage along a length thereof and said housing is configured to support the first group and the second group in a spaced apart relationship along said length and surrounding the through passage such that, responsive to the drill rig pushing on the drill string, a first one of the first and second groups is subject to a first compressive force and responsive to the drill rig pulling on the drill string the other one of the first and second groups is subject to a second compressive force without subjecting either of the first and second groups to a tension force during said pushing and pulling by the drill rig to form an electrically isolating break in the drill string. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 56, 57, 58, 59, 60)
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52. An apparatus for use in combination with a drill string that is electrically conductive and extends from an inground distal end, that includes an inground tool, to a drill rig, said drill rig configured to rotate the drill string which applies a rotational torque to the drill string, said apparatus comprising:
a housing that is configured to support a group of electrical isolators to electrically isolate a downhole portion of the drill string from an uphole portion of the drill string and configured to support the group of electrical isolators subject only to a compressive force responsive to the rotational torque. - View Dependent Claims (53, 54, 55)
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61. A method for electrically isolating a downhole portion of a drill string from an uphole portion of the drill string which drill string includes an inground distal end having an inground tool such that the drill string extends from the inground distal end to the drill rig, said method comprising:
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in a housing which housing has a housing length, supporting a first group of electrical isolators and a second group of electrical isolators such that the first group and the second group are in a spaced apart relationship along said housing length; and subjecting a first one of the first and second groups to a first compressive force responsive to the drill rig pushing on the drill string and subjecting the other one of the first and second groups to a second compressive force responsive to the drill rig pulling on the drill string without subjecting either of the first and second groups to a tension force during said pushing and pulling by the drill rig to form an electrically isolating break in the drill string. - View Dependent Claims (62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87)
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88. In forming an electrically isolating break in an electrically conductive drill string that extends from a drill rig to an inground distal end, with said drill rig configured to rotate the drill string to apply a rotational torque to the inground distal end, a method comprising:
arranging a housing in the drill string to support an arrangement of elongated members that are electrical insulators to electrically isolate a downhole portion of the drill string, including said distal end, from an uphole portion of the drill string and subjecting the elongated members only to a compressive force responsive to the rotational torque. - View Dependent Claims (89, 90, 91, 92, 93, 94, 95, 96)
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97. An apparatus for use in combination with an electrically conductive drill string and which drill string extends from an inground distal end, including an inground tool, to a drill rig, said apparatus comprising:
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a plurality of electrical isolators; and a housing defining a through passage and having an elongated housing length that is configured to support the plurality of electrical isolators under a compressive preload that is applied by the housing in a direction that is aligned with the elongated housing length such that an overall compressive force that is applied to the electrical isolators varies responsive to push and pull forces that are applied to the drill string by the drill rig and the electrical isolators cooperate with the housing to form an electrically isolating gap between said inground distal end and said drill rig. - View Dependent Claims (98, 99, 100)
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101. A method for forming an electrically isolated gap in an electrically conductive drill string between an inground distal end of the drill string including an inground tool and a drill rig to which the drill string extends, said method comprising:
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providing a plurality of electrical isolators; forming a housing defining a through passage and having an elongated housing length that is configured to support the plurality of electrical isolators; and applying a compressive preload to the electrical isolators from the housing in a direction that is aligned with an elongation axis of the drill string such that an overall compressive force that is applied to the electrical isolators varies responsive to push and pull forces that are applied to the drill string by the drill rig and the electrical isolators cooperate with the housing to form an electrically isolated gap between said inground distal end and said drill rig. - View Dependent Claims (102, 103, 104)
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105. An apparatus for use in combination with a drill string that is electrically conductive and extends from an inground distal end that includes an inground tool, to a drill rig, said apparatus comprising:
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a first group of electrical isolators and a second group of electrical isolators; a first housing body that is electrically conductive and defines a first drill string fitting; a second housing body that is electrically conductive having opposing first and second ends and configured to cooperate with the first housing body to support the first group of electrical isolators at the first end of the second housing body and the second group of electrical isolators at the second end of the second housing body such that the first housing body is electrically isolated from the second housing body; and an interchangeable body that is electrically conductive and configured for removably fixed engagement with the second end of the second housing body and said interchangeable body is selectable as each of (i) said inground tool to form the inground distal end of the drill string and (ii) a second, opposing drill string fitting such that the apparatus is insertable into a joint in the drill string that would otherwise be formed between adjacent drill rods as the drill string is extended. - View Dependent Claims (106, 107, 108)
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109. A method to provide an apparatus for use in combination with a drill string that is electrically conductive and extends from an inground distal end that includes an inground tool, to a drill rig, said method comprising:
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providing a first group of electrical isolators and a second group of electrical isolators; configuring a first housing body as electrically conductive and to define a first drill string fitting; configuring a second housing body as electrically conductive and to have opposing first and second ends and to cooperate with the first housing body to support the first group of electrical isolators at the first end of the second housing body and the second group of electrical isolators at the second end of the second housing body such that the first housing body is electrically isolated from the second housing body; and forming an interchangeable body that is electrically conductive and configured for removably fixed engagement with the second end of the second housing body and said interchangeable body is selectable as each of (i) said inground tool to form the inground distal end of the drill string and (ii) a second, opposing drill string fitting such that the apparatus is insertable into a joint in the drill string that would otherwise be formed between adjacent drill rods as the drill string is extended. - View Dependent Claims (110, 111, 112)
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113. An apparatus for use in combination with a drill string that is electrically conductive and extends from an inground distal end that includes an inground tool, to a drill rig, said apparatus comprising:
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a first group of electrical isolators and a second group of electrical isolators; a first housing body that is electrically conductive and defines a first drill string fitting; a second housing body that is electrically conductive having opposing first and second ends and configured to cooperate with the first housing body to support the first group of electrical isolators at the first end of the second housing body and the second group of electrical isolators at the second end of the second housing body such that the first housing body is electrically isolated from the second housing body; and an interchangeable body that is electrically conductive and configured for removably fixed engagement with the second end of the second housing body and said interchangeable body is configured to perform a selected one of at least two different inground operations.
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Specification