Apparatus and methods for handling drill string

An apparatus for handling a drill string having an up-hole end, a mid-section and a down-hole end, the apparatus comprising:

• a first tension mechanism;
• a second tension mechanism;
• an up-hole cable operably connectable between the first tension mechanism and the up-hole end of the drill string;
• a down-hole cable operably connectable between the second tension mechanism and a connection location in the mid-section of the drill string;
• and
• a guide defining an elongated channel for receiving the drill string;
• the guide located relative to the first tension mechanism, the second tension mechanism, the up-hole cable and the down-hole cable so that force applied to the up-hole end of the drill string by the first tension mechanism via the up-hole cable pulls the drill string upwardly through the elongated channel and outwardly from a wellbore and, when the mid-section of the drill string is located in the channel of the guide, force applied to the mid-section of the drill string by the second tension mechanism via the down-hole cable pulls the drill string downwardly through the elongated channel to facilitate at least partial re-insertion of the drill string into the wellbore;
• and
• the guide shaped to prevent the drill string from bending, as the drill string is pulled through the elongated channel, in a manner that is sharper than a minimum threshold radius of curvature for the drill string;
• wherein the guide comprises:
• a tail end through which the drill string enters the guide as the drill string is removed from the wellbore and pulled upwardly into the guide by the first tension mechanism via the up-hole cable;
• and
• a corresponding tail section that is relatively more proximate to the tail end than a remainder of the guide;
• wherein at least a portion of the tail section is shaped to provide the elongated channel with an enclosed shape, the enclosed shape surrounding a transverse cross-section of the drill string located in the elongated channel at the at least a portion of the tail section;
• and
• wherein at least a portion of the remainder of the guide is shaped to provide the elongated channel with an open shape, the open shape surrounding only a portion of a transverse cross-section of the drill string located in the elongated channel at the at least a portion of the remainder of the guide
• wherein the at least a portion of the tail section comprises a moveable cover, the moveable cover moveable between a closed configuration that provides the at least a portion of the tail section with the enclosed shape and an open configuration that provides the at least a portion of the tail section with an open shape which surrounds only a portion of the transverse cross-section of the drill string located in the elongated channel at the at least a portion of the tail section.

A method for handling drill string having an up-hole end, a mid-section and a down-hole end, the method comprising:

• pulling a drill string out from a wellbore, wherein pulling the drill string out from the wellbore comprises:
• connecting an up-hole cable between a first tension mechanism and the up-hole end of the drill string;
• pulling the up-hole cable and the drill string upwardly into a guide;
• and
• lowering the drill string from the guide back into the wellbore, wherein lowering the drill string from the guide back into the wellbore comprises:
• connecting a down-hole cable between a second tension mechanism and a connection location in the mid-section of the drill string;
• pulling the down-hole cable and the drill string downwardly out from the guide to facilitate at least partially re-inserting the drill string into the wellbore;
• at a release configuration, where at least an up-hole portion of the drill string is located in the guide and at least a down-hole portion of the drill string is located in the wellbore, disconnecting at least one of:
• the second tension mechanism from the down-hole cable;
• and the down-hole cable from the drill string;
• and
• after the disconnecting, permitting gravity to pull the drill string further downwardly out from the guide to facilitate further re-inserting the drill string into the wellbore;
• wherein the guide comprises:
• a tail end through which the drill string enters the guide as the drill string is pulled upwardly into the guide;
• and a corresponding tail section that is relatively more proximate to the tail end than a remainder of the guide;
• and
• the method comprises moving the tail section relative to the remainder of the guide between:
• a lowered configuration where the tail section and the remainder of the guide provide an elongated drill-string receiving channel of the guide with a smooth shape;
• and a raised configuration where the tail end introduces a discontinuity into a shape of the elongated channel.

A method for handling drill string having an up-hole end, a mid-section and a down-hole end, the method comprising:

• pulling a drill string out from a wellbore, wherein pulling the drill string out from the wellbore comprises:
• connecting an up-hole cable between a first tension mechanism and the up-hole end of the drill string;
• pulling the up-hole cable and the drill string upwardly into a guide;
• and
• lowering the drill string from the guide back into the wellbore, wherein lowering the drill string from the guide back into the wellbore comprises:
• connecting a down-hole cable between a second tension mechanism and a connection location in the mid-section of the drill string;
• pulling the down-hole cable and the drill string downwardly out from the guide to facilitate at least partially re-inserting the drill string into the wellbore;
• at a release configuration, where at least an up-hole portion of the drill string is located in the guide and at least a down-hole portion of the drill string is located in the wellbore, disconnecting at least one of:
• the second tension mechanism from the down-hole cable;
• and the down-hole cable from the drill string;
• and
• after the disconnecting, permitting gravity to pull the drill string further downwardly out from the guide to facilitate further re-inserting the drill string into the wellbore;
• wherein:
• the guide comprises:
• a tail end through which the drill string enters the guide as the drill string is pulled upwardly into the guide;
• and a corresponding tail section that is relatively more proximate to the tail end than a remainder of the guide;
• at least a portion of the tail section is shaped to provide the elongated channel with an enclosed shape, the enclosed shape surrounding a transverse cross-section of the drill string located in the elongated channel at the at least a portion of the tail section;
• and
• at least a portion of the remainder of the guide is shaped to provide the elongated channel with an open shape, the open shape surrounding only a portion of a transverse cross-section of the drill string located in the elongated channel at the at least a portion of the remainder of the guide.