In preparation for directional drilling, a wedge supported distally ahead of a tubular drill string is advanced along a parent hole. The wedge is connected to the drill string by a rigid link that extends along a central longitudinal axis through an annular cutting head. The wedge may be connected to the drill string via an inner dropper mechanism that can be engaged by a wireline lifting system. After locking the wedge at a kick-off point in the hole at a desired azimuth, the connection of the link is broken. The dropper mechanism can then be retrieved and replaced by an inner core tube, without moving the drill string. The drill string is then advanced to drill a daughter hole that branches from the parent hole on the azimuth determined by the wedge. Advantageously, there is no need to withdraw the drill string before drilling the daughter hole can commence.
E21B 7/06 - Modification de la direction du trou de forage
E21B 23/04 - Appareils pour déplacer, mettre en place, verrouiller, libérer ou retirer, les outils, les packers ou autres éléments dans les trous de forage mis en œuvre à l'aide de moyens fluides, p. ex. actionnés par explosion
E21B 25/02 - Appareils pour recueillir ou retirer des carottes intactes, p. ex. tubes carottiers ou extracteurs de carottes le réceptacle de la carotte pouvant être introduit dans le trou de forage ou en être enlevé sans retirer le tube de forage
E21B 47/024 - Détermination de l'inclinaison ou de la direction des dispositifs dans le trou de forage
In preparation for directional drilling, a wedge supported distally ahead of a tubular drill string is advanced along a parent hole. The wedge is connected to the drill string by a rigid link that extends along a central longitudinal axis through an annular cutting head. The wedge may be connected to the drill string via an inner dropper mechanism that can be engaged by a wireline lifting system. After locking the wedge at a kick-off point in the hole at a desired azimuth, the connection of the link is broken. The dropper mechanism can then be retrieved and replaced by an inner core tube, without moving the drill string. The drill string is then advanced to drill a daughter hole that branches from the parent hole on the azimuth determined by the wedge. Advantageously, there is no need to withdraw the drill string before drilling the daughter hole can commence.
E21B 7/06 - Modification de la direction du trou de forage
E21B 23/04 - Appareils pour déplacer, mettre en place, verrouiller, libérer ou retirer, les outils, les packers ou autres éléments dans les trous de forage mis en œuvre à l'aide de moyens fluides, p. ex. actionnés par explosion
E21B 25/02 - Appareils pour recueillir ou retirer des carottes intactes, p. ex. tubes carottiers ou extracteurs de carottes le réceptacle de la carotte pouvant être introduit dans le trou de forage ou en être enlevé sans retirer le tube de forage
E21B 47/024 - Détermination de l'inclinaison ou de la direction des dispositifs dans le trou de forage
In preparation for directional drilling, a wedge supported distally ahead of a tubular drill string is advanced along a parent hole. The wedge is connected to the drill string by a rigid link that extends along a central longitudinal axis through an annular cutting head. The wedge may be connected to the drill string via an inner dropper mechanism that can be engaged by a wireline lifting system. After locking the wedge at a kick-off point in the hole at a desired azimuth, the connection of the link is broken. The dropper mechanism can then be retrieved and replaced by an inner core tube, without moving the drill string. The drill string is then advanced to drill a daughter hole that branches from the parent hole on the azimuth determined by the wedge. Advantageously, there is no need to withdraw the drill string before drilling the daughter hole can commence.
E21B 7/06 - Modification de la direction du trou de forage
E21B 23/01 - Appareils pour déplacer, mettre en place, verrouiller, libérer ou retirer, les outils, les packers ou autres éléments dans les trous de forage pour ancrer les outils ou similaires
E21B 25/02 - Appareils pour recueillir ou retirer des carottes intactes, p. ex. tubes carottiers ou extracteurs de carottes le réceptacle de la carotte pouvant être introduit dans le trou de forage ou en être enlevé sans retirer le tube de forage
In preparation for directional drilling, a wedge supported distally ahead of a tubular drill string is advanced along a parent hole. The wedge is connected to the drill string by a rigid link that extends along a central longitudinal axis through an annular cutting head. The wedge may be connected to the drill string via an inner dropper mechanism that can be engaged by a wireline lifting system. After locking the wedge at a kick-off point in the hole at a desired azimuth, the connection of the link is broken. The dropper mechanism can then be retrieved and replaced by an inner core tube, without moving the drill string. The drill string is then advanced to drill a daughter hole that branches from the parent hole on the azimuth determined by the wedge. Advantageously, there is no need to withdraw the drill string before drilling the daughter hole can commence.
E21B 7/06 - Modification de la direction du trou de forage
E21B 25/02 - Appareils pour recueillir ou retirer des carottes intactes, p. ex. tubes carottiers ou extracteurs de carottes le réceptacle de la carotte pouvant être introduit dans le trou de forage ou en être enlevé sans retirer le tube de forage
E21B 23/01 - Appareils pour déplacer, mettre en place, verrouiller, libérer ou retirer, les outils, les packers ou autres éléments dans les trous de forage pour ancrer les outils ou similaires
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