Abstract: The present invention relates to acirculation subassembly (circsub) for incorporation in a drill pipe. The circsub has a flow through condition in which the circsub allows fluid to flow through a bore of the circsub and does not allow fluid communication between the bore of the circsub and an annulus located outside the drill pipe, a partial bypass condition in which the circsub allows fluid to flow through the bore of the circsub and allows fluid communication between the bore of the circsub and the annulus, and a full bypass condition in which the circsub does not allow fluid to flow through the bore of the circsub and allows fluid communication between the bore of the circsub and the annulus. An actuator is provided to change the circsub between conditions under the control of a controller.

Abstract: A downhole tool for incorporation in a drill pipe for selective operation of the tool from surface level when the tool is in a wellbore. The tool comprises a controller electrically powered by a power source separate from surface level, a first sensor of the controller to detect a dynamic variable of the tool in the wellbore and produce an output signal dependent thereon; a second sensor of the controller to detect a mechanical signal transmitted from an operator at surface level; a motor driven by the power source under the control of the controller when said mechanical signal is received; and an actuator driven by the motor to actuate the tool; wherein the controller switches between at least two states in response to changes in said dynamic variable, only in said second state the controller being receptive to said mechanical signal from the operator to drive the motor. The tool may be a disconnect device and/or a circ sub.

Abstract: Circulation Subassembly The present invention relates to acirculation subassembly (circsub) for incorporation in a drill pipe. The circsub has a flow through condition in which the circsub allows fluid to flow through a bore of the circsub and does not allow fluid communication between the bore of the circsub and an annulus located outside the drill pipe, a partial bypass condition in which the circsub allows fluid to flow through the bore of the circsub and allows fluid communication between the bore of the circsub and the annulus, and a full bypass condition in which the circsub does not allow fluid to flow through the bore of the circsub and allows fluid communication between the bore of the circsub and the annulus. An actuator is provided to change the circsub between conditions under the control of a controller.

Abstract: A downhole tool for incorporation in a drill pipe for selective operation of the tool from surface level when the tool is in a wellbore. The tool comprises a controller electrically powered by a power source separate from surface level, a first sensor of the controller to detect a dynamic variable of the tool in the wellbore and produce an output signal dependent thereon; a second sensor of the controller to detect a mechanical signal transmitted from an operator at surface level; a motor driven by the power source under the control of the controller when said mechanical signal is received; and an actuator driven by the motor to actuate the tool; wherein the controller switches between at least two states in response to changes in said dynamic variable, only in said second state the controller being receptive to said mechanical signal from the operator to drive the motor. The tool may be a disconnect device and/or a circ sub.

Abstract: A downhole tool (10?) comprises a body (12?) having a longitudinal axis and a body through-bore (14?), a slot (34?) communicating the outside of the body with the body through-bore. A sleeve actuator (30?) mandrel also has a bore and is selectively axially slidable in the body through-bore. A hollow bar (36?) is slidable with a radial component in the slot. At least two levers (210), each pivoted to the mandrel (about a first axis perpendicular the longitudinal axis) extend into the hollow bar and are pivoted thereto (about a second axis parallel the first axis). The levers lie in an actuation plane perpendicular the first and second axes and containing the slot. The levers are disposed at an inclined angle with respect to the longitudinal axis so that longitudinal motion of the mandrel translates into radial movement of the bar.

Abstract: A downhole tool comprises a body having slots communicating the outside of the body with the body through-bore. A sleeve actuator and mandrel are selectively axially slidable. The actuator has flanges extending into the slots. The flanges have ribs on their sides that are inclined at an acute angle to the longitudinal axis of the tool. Hollow bars are slidable in the slots and they have channels inside corresponding with, and engaged in, the ribs of the flanges. The sleeve actuator slides in the body between a tool actuated position and a tool deactuated position. The mandrel is selectively axially slidable between a tool actuated position, an interlock position and a sleeve-lock position. A lock ball locks the sleeve actuator with respect to the body in the tool deactuated position and while the mandrel is between the interlock and sleeve-lock positions. The lock ball also locks the sleeve actuator with respect to the mandrel while the mandrel is between said interlock and tool actuated positions.

Abstract: A stabiliser (10) has a body (12) having a through-bore (16). A mandrel (14), also having a through-bore (20), is axially slidable in the body bore to actuate and de-actuate the tool. A step (64) in the body defines annular chambers (102, 104) between the mandrel and body on either side of the step. A control piston (18) in the mandrel alternately directs drilling mud pumped under pressure along said body bore and mandrel bore to the chambers to drive the mandrel hydraulically to actuate and de-actuate the tool. The control piston has a through-bore (46) and is slidable in the mandrel bore against the force of a return spring (40) by drilling mud pressure from a low-pressure position to a pressure position. The pressure position is alternately one of an actuate position (a) and a de-actuate position (b), axially spaced along the mandrel bore from said actuate position.

Abstract: An adjustable down-hole tool, for example a drill-string stabiliser (10), comprises a body (12) having a through bore (16). A mandrel (18) is rotationally fixed but axially movable in the body, the mandrel being movable by fluid pressure in the tool against the action of a first return spring (44) between a first, activated position and a second deactivated position. A sleeve (66) is between shoulders (68, 69) on the body and mandrel. Castellations (18a,b, 69a,b) are on the mandrel and facing edge or edges of the sleeve so that, when the castellations are in phase the mandrel is prevented from travelling from said first to second position and when they are out of phase they interdigitate and the mandrel is not prevented from travelling from said first to second position. A control piston (36) is slidable in the mandrel, being movable by fluid pressure in the tool against the action of a second return spring (50).

Abstract: An adjustable down-hole tool, for example a drill-string stabiliser (10), comprises a body (12) having a through bore (16). A mandrel (18) is rotationally fixed but axially movable in the body, the mandrel being movable by fluid pressure in the tool against the action of a first return spring (44) between a first, activated position and a second deactivated position. A sleeve (66) is between shoulders (68, 69) on the body and mandrel. Castellations (18a,b, 69a,b) are on the mandrel and facing edge or edges of the sleeve so that, when the castellations are in phase the mandrel is prevented from travelling from said first to second position and when they are out of phase they interdigitate and the mandrel is not prevented from travelling from said first to second position. A control piston (36) is slidable in the mandrel, being movable by fluid pressure in the tool against the action of a second return spring (50).

Abstract: An adjustable down-hole tool, for example a drill-string stabiliser (10), comprises a body (12) having a through bore (16). A mandrel (18) is rotationally fixed but axially movable in the body, the mandrel being movable by fluid pressure in the tool against the action of a first return spring (44) between a first, activated position and a second deactivated position. A sleeve (66) is between shoulders (68, 69) on the body and mandrel. Castellations (18a,b, 69a,b) are on the mandrel and facing edge or edges of the sleeve so that, when the castellations are in phase the mandrel is prevented from travelling from said first to second position and when they are out of phase they interdigitate and the mandrel is not prevented from travelling from said first to second position. A control piston (36) is slidable in the mandrel, being movable by fluid pressure in the tool against the action of a second return spring (50).

Abstract: A feed beam for a rockdrill has slide guides along which the rockdrill can slide on the beam, with the working surfaces of the slides being removable and replaceable. The removable slide guides on the beam itself entirely determine the profile of the slide guide, and the rockdrill is supported by the detachable slide guides and by the connections between these slide guides and the feed beam. In a similar manner, the feed beam is located on a support frame of a drill boom or similar component and can be driven along the support frame by a hydraulic cylinder or other similar means.