Abstract: A downhole catcher device comprises a catching mechanism which is configured to be transferable between a first mode and a second mode. The catching mechanism is further configured for passing by a first operation element if the catching mechanism is in the first mode and for catching a second operation element if the catching mechanism is in the second mode. The transfer between the first and the second mode is triggered (or effected) by a downhole tool which is operated by the second operation element.

Abstract: A splitflow valve comprises a tubular body, a valve element and a lock. The tubular body defines a through hole and has at least one lateral bypass port. The valve element defines a flow restriction and is moveable along the through hole along a first direction between a first position and a second position, wherein the bypass port is closed by the valve element in the first position. In the second position the bypass port is open. The lock maintains the valve element in the second position wherein a flow of fluid entering the through hole of the tubular body is split into a first flow portion passing the flow restriction and a second flow portion exiting the at least one bypass port. Further, the lock is deactivatable to allow the valve element to return to the first position.

Abstract: A drillstring valve has an inlet mountable to a drillstring, an outlet and a passageway extending between the inlet and the outlet in a predetermined operating condition. The drillstring valve comprises a stop element adapted for receiving a valve element wherein the stop element comprises at least two protrusions extending into a passageway portion of the passageway to thereby retain the valve element. The at least two protrusions are spaced in a circumferential direction of the passageway portion and may be spaced from an inlet edge having a continuously reduced diameter in a downstream direction.

Abstract: A drillstring valve has an inlet mountable to a drillstring, an outlet and a passageway extending between the inlet and the outlet in a predetermined operating condition. In accordance with an embodiment, the drillstring valve comprises a stop element adapted for receiving a valve element wherein the stop element comprises at least one protrusion extending into a passageway portion of the passageway to thereby retain the valve element. According to an embodiment, the at least one protrusion is spaced from an inlet edge having a continuously reduced diameter in downstream direction. According to a further embodiment, the stop element comprises two or more protrusions which are spaced in circumferential direction of the passageway portion into which the at least two protrusions extend.

Abstract: A downhole circulation apparatus comprises at least one tubular body portion defining a first through-flow passage through which drilling fluid can pass along the drill string. A first sleeve is slidably mounted in the tubular body portion and is biased into a position in which the first port means is closed by a biasing means such as a spring. Second port means is formed through the tubular body portion at a location below the first port means in the drill string. The second port means may comprise a plurality of second nozzles, wherein each of the second nozzles has a diameter greater than the diameter of each of the first nozzles of the first port means. Larger nozzles enable large particle size drilling fluid to be bypassed. A second sleeve is slidably mounted inside the tubular body portion.

Abstract: An activating mechanism for controlling the operation of a downhole tool in a drill string and which is intended to be housed in a portion of the drill string upstream of the downhole tool, in which: the activating mechanism has a first mode in which it allows through-flow of drilling fluid to the downhole tool and a second mode in which through-flow of fluid is blocked; and the activating mechanism has a number of through-flow ports permitting through-flow of drilling fluid in said first mode of the mechanism and which are capable of being blocked by launching a number of flow blocking activator balls down the drill string and which each are of such size and shape that they can block access to said through-flow ports in order to activate the mechanism to the second mode and thereby adjust the downhole tool from one mode of operation to another.