Abstract: An apparatus for cutting a wellbore includes a motor having a stator and a rotor. The rotor has an output shaft connected to a cutting structure. The stator and rotor are spaced radially outwardly of the axis of rotation of the rotor such that at least one of the stator and the rotor had an access bore extending through the motor to adjacent the cutting structure. A further object can pass therethrough, without obstruction. The further object comprises a further cutting. A flow diverter is disposed in the motor proximate a connection between the motor and a wellbore tubular, and has a first fluid outlet in fluid communication with a power section of the motor, and a second fluid outlet in fluid communication with the access bore. The flow diverter is coupled to the stator such that axial loading created by fluid pressure is substantially transferred to the stator.

Abstract: Methods, systems, and tool assemblies for distributing weight between a bit and a reamer device are disclosed. For example, at least one of the drill bit and the reamer may be configured to selectively distribute a weight-on-bit between the drill bit and the reamer, such as within a predetermined range. Additionally, methods of drilling wellbores may include selectively distributing a weight-on-bit applied to a bottom hole assembly between a drill bit and a reamer of the bottom hole assembly. Also, a reamer may be configured to exhibit a first maximum rate-of-penetration into a relatively hard formation, and a drill bit may be configured to exhibit a second maximum rate-of-penetration into a relatively soft formation that is less than the first maximum rate-of-penetration.

Abstract: A system and method for building and handling oilfield tubular stands while drilling operations are simultaneously and independently occurring with one drilling deck, one derrick, and one rotary system. An offline guided path horizontal to vertical arm lifts and moves in the same plane tubulars stored horizontally on the catwalk and positions the tubulars vertically directly into a preparation hole for assembling and disassembling tubular stands while online drilling operations are simultaneously being conducted. A stand arm lifts and lowers the tubulars into and out of the adjustable preparation hole, and transports the tubulars for storage to an auxiliary tubular racking station in the upper part of the derrick. A bridge racker crane moves tubular stands from the auxiliary tubular racking station to the top drive or another tubular racking station.

Abstract: In one aspect, the invention provides a method for modeling the wear of a fixed cutter bit drilling earth formations. A method for determining wear of a fixed cutter drill bit includes simulating the fixed cutter drill bit drilling an earth formation; determining a cutter-formation interaction force and a relative sliding velocity of a selected area on a cutting surface on a cutter of the fixed cutter drill bit during the drilling; and calculating a wear rate of the selected area based on the cutter-formation interaction force and the relative sliding velocity.

Abstract: Expandable reamers for enlarging wellbores include a tubular body and one or more blades configured to extend and retract. A sleeve member within the tubular body has open ends to allow fluid to flow therethrough. A fluid port extends through a wall of the sleeve member. A restriction member within the sleeve is movable between first and second positions. In the first position, fluid flow through the downhole end of the sleeve is generally unimpeded, and fluid flow through the fluid port is generally impeded. In the second position, fluid flow through the downhole end of the sleeve member is generally impeded, and fluid flow through the fluid port is generally unimpeded. The restriction member may be configured to move responsive to changes in the rate of fluid flow through the sleeve member. Methods of using such reamers are also disclosed.

Abstract: An apparatus includes a carriage movable along a drilling tower, a linking member pivotally coupled to the carriage, at least one actuator extending between the carriage and the linking member to pivot the linking member between first and second pivot positions, and a top drive pivotally coupled to the linking member. According to another aspect, an apparatus includes a drilling tower, a carriage movably coupled to the drilling tower, a linking member pivotally coupled to the carriage to permit the linking member to pivot between first and second pivot positions, and a top drive extending longitudinally in a parallel relation to the drilling tower, the top drive being pivotally coupled to the linking member to permit the top drive to continue to extend longitudinally in a parallel relation to the drilling tower when the linking member pivots between the first and second pivot positions.

Abstract: A mud motor bearing assembly for use in drilling a hydrocarbon well. The bearing assembly includes a bearing section containing stationary bearing rigs and rotating bearing rings in stacked arrangement. The bearing rings have wedge-shaped projections. The wedge-shaped projections of two adjacent stationary bearing rings form a recess to accommodate the projection of a rotating bearing ring in sliding engagement. The bearing assembly is capable of bearing both radial and axial loads.

Abstract: A shaped charge having a charge case and liner with an outer layer and an inner layer. The liner is a generally hollow frustoconically shaped member with an open end and a closed end, where the closed end of the liner inserts into an opening in the charge case. An explosive is provided between the liner and the charge case. The inner layer of the liner includes a higher density material than material used for forming the outer layer.

Abstract: The present apparatus and method of use allows a blow out preventer to be installed as a unit with a section of casing, and does not require the blow out preventer to be removed as subsequent strings of casing are installed, thus efficiently utilizing drilling rig time. The present invention further allows a casing string to be landed and cemented in place, and then the drilling rig may move off the location, without a permanent wellhead housing attached to the well. The primary apparatus utilized in the invention is a tubular connector which suspends a string of casing during cementing, and which receives a casing plug for sealing the well when drilling operations have been completed. When completion operations commence, a permanent wellhead housing is attached to the tubular connector utilizing a unique metal to metal seal.

Abstract: A method for coupling an earth pipe into the ground when utilizing an apparatus that has a drilling device including a casing part and a drilling unit inside thereof. The drilling unit includes a first drilling member for drilling a center hole and a second drilling member for reaming the center hole for the casing part. The casing part is arranged to be drawn into the hole by the first and/or second drilling member. After drilling a hole for the earth pipe and lifting up the first drilling member, a solidifying mass is led to the bottom of the hole to couple the earth pipe to the surrounding ground. The solidifying mass is brought in the casing part utilizing a flow-through assembly at a lower end of the casing part into a space between an outer surface of the casing part and the hole. Also an apparatus operating.

Abstract: Device for lining the wall of a wellbore as it is being drilled using a drill string having a drill bit on the lower end thereof. The device has a receptacle for a cylindrically gathered pack of flexible tubing capable of being supported around the outside of the drill string near the lower end thereof on a plurality of bearings, a radially expandable locking device attachable to one end of the flexible tubing and being capable of being expanded against the wellbore wall to lock the end of the flexible tubing in place in the wellbore, and a conduit having an inlet upstream of the receptacle and an outlet downstream of the receptacle. A pump is located in the conduit or abutting the inlet or outlet thereof, and pumps the drilling fluid so that a fluid pressure inside the liner is greater than a fluid pressure at the drill bit.

Abstract: A method for determining existence of a borehole fluid control event by controlling formation pressure during the drilling of a borehole includes selectively pumping a drilling fluid through a drill string extended into a borehole, out a drill bit at the bottom end of the drill string, and into an annular space between drill string and the borehole. The drilling fluid leaves the annular space proximate the surface. Existence of a well control event is determined when at least one of the following events occurs: the rate of the selective pumping remains substantially constant and the annular space pressure increases, and the rate of the selective pumping remains substantially constant and the annular space pressure decreases.

Abstract: A system for drilling a borehole according to the present invention includes a drill rig and a control system. The control system receives information from the drill rig that relates to at least one drill parameter. The control system processes information relating to the drill parameter, determines whether the drill parameter is within a predetermined specification for the monitored drill parameter, chooses a hole defect mitigation routine based on the monitored drill parameter when the monitored drill parameter is outside the predetermined specification, and controls the drill rig to implement the chosen hole defect mitigation routine.

Abstract: The invention relates to a ground working device comprising a carrier implement, a mast that forms a mast sequence and has a lower mast part, which is linked to the carrier implement, an upper mast part and at least one mast extension piece, whereby for the purpose of increasing the mast length the mast extension piece is removably inserted into the mast sequence between lower mast part and upper mast part and removed from the mast sequence, and, with the mast extension piece removed, the upper mast part can be fixed directly on the lower mast part, a work sledge which is guided in a displaceable manner along the mast, and at least one feed rope for displacing the work sledge, which runs at least in some areas longitudinally of the mast.

Abstract: The invention relates to a method for introducing a vertical shaft underground and to a shaft driving machine set up particularly for performing the method, wherein a cutting wheel is rotated solely about a horizontal axis until a penetration trough having a predetermined penetration depth is formed, and the cutting wheel is then also rotated about a central vertical axis until a shaft foot is dug out to the penetration depth. A relatively high sinking rate is thereby achieved for the shaft.

Abstract: A downhole tool having a progressive cavity mud motor with an impact generator disposed within the mud motor rotor or bearing assembly. In one embodiment, the impact generator includes a mud turbine connected to a eccentric ring that encircles and periodically strikes an anvil surface of a percussion shaft. The eccentric ring is pivotable between an engaged striking position and a disengaged non-striking position. The percussion shaft is coupled to a drill bit though a splined connector that provides limited slip for transmitting rotation of the mud motor rotor to the drill bit and for transmitting percussion strikes against the anvil to the drill bit without the need to accelerate the entire drill string.

Abstract: A drill bit for drilling a borehole in an earthen formation may include a bit body having a bit axis and a direction of rotation about the bit axis; at least two blades extending azimuthally from the bit body; and a plurality of cutting elements disposed on the at least two blades; the plurality of cutting elements forming a cutting profile in a rotated profile view, each cutting element having a radial distance from the bit axis. At least one blade, at its formation facing surface, may include, between two radially adjacent cutting elements on the at least one blade, a raised depth of cut feature for each cutting element on the other of the at least two blades that are at radial distances from the bit axis intermediate the radial distances from the bit axis of the radially adjacent cutting elements on the at least one blade.

Abstract: Disclosed herein is a telescoping substructure of a drilling rig that includes first and second telescoping substructure boxes. The first and second telescoping substructure boxes each include, among other things, a lower substructure box and an upper substructure box that is adapted to be telescopically raised and lowered relative to the lower substructure box. Furthermore, each telescoping substructure box also includes raising means for telescopically raising and lowering the upper substructure box relative to the lower substructure box between a collapsed configuration for transportation and a raised configuration for drilling operations, wherein each of the first and second telescoping substructure boxes are adapted to facilitate movement of the telescoping substructure in at least one of a lateral direction and a longitudinal direction over wellhead equipment positioned above a wellbore location when the upper substructure boxes are in the raised configuration.

Abstract: A downhole apparatus connected to a workstring within a wellbore. The workstring is connected to a bit member. The apparatus includes a mandrel operatively connected to a downhole motor mechanism, an anvil member operatively formed on the bit member, the anvil member being operatively connected to the mandrel, a radial bearing housing unit operatively connected to the workstring, with the radial bearing housing unit being disposed about the mandrel, and a hammer member slidably attached to the radial bearing housing unit.

Abstract: A drilling method comprises controlling operation of a drill string to maintain at least a portion of the drill string in forward whirl.

Abstract: Expandable reamers for enlarging a borehole in a subterranean formation include a tubular body, at least one curved blade track carried by the tubular body, and at least one blade engaged with the at least one blade track and configured to slide along the curved blade track along a curved path between a first retracted blade position and a second expanded blade position. To form such an expandable reamer, a tubular body having at least one curved blade track carried by the tubular body may be formed, and at least one blade may be engaged with the blade track. The blade and blade track may be configured such that the blade slides along the blade track along a curved path between a retracted position and an expanded position. Such expandable reamers may be used to enlarge boreholes in subterranean formations.

Abstract: A down hole tool includes a tool body, a fluid cavity, a magnetorheological fluid disposed in the fluid cavity, and an electrical control unit in communication with the MR fluid. The electrical control unit is configured to adjust a viscosity of the MR fluid by varying a magnetic field.

Abstract: Expandable reamers comprise a housing and at least one blade supported by the housing. The at least one blade is movable between an extended position and a retracted position. The at least one blade is in the retracted position when a travel sleeve is in a first sleeve position and a trigger sleeve is in an unobstructed position. The at least one blade is movable to the extended position when the travel sleeve is in a second sleeve position and the trigger sleeve is in the unobstructed position. The at least one blade is in the retracted position when the travel sleeve is in the second sleeve position and the trigger sleeve is in an obstructed position.

Abstract: Cutting structures for use with downhole tools in subterranean boreholes include a blade, a plurality of primary cutting elements coupled to the blade, and at least one secondary element rotationally leading the plurality of primary cutting elements in a direction of intended rotation of the cutting structure. The at least one secondary element is coupled to the blade proximate a leading surface of the blade and comprises at least one of a rubbing surface and a cutting surface. An exposure of at least one primary cutting element of the plurality of primary cutting elements is greater than an exposure of the at least one secondary element. Downhole tools such as reamers include cutting structures. Methods of enlarging a subterranean borehole include reaming a borehole with cutting structures.

Abstract: An articulated reaming tool is provided in casing or liner drilling on or through the tubular wall with the articulation occurring from within the tubular. Outer limit travel stops are contemplated to optionally be used to retain the elements or blades to the tubular. In the case of liner drilling the drill string has an exterior protrusion to engage the movable components that ream and extend them to increase the clearance for the tubular as the tubular advances when more hole is made.

Abstract: A method of servicing a wellbore comprises determining a cation exchange capacity of a sample of a shale, determining a swelling characteristic of the shale using the cation exchange capacity in an equation comprising a term of the form: Az% salt=x(cation exchange capacity)y where Az% salt is a final swelling volume of the shale in the presence of an aqueous fluid having a salt concentration of z %, and x and y are empirical constants, determining a composition of a wellbore servicing fluid based on the determined swelling characteristic, and drilling the wellbore using the wellbore servicing fluid.

Abstract: Disclosed are hydrocarbon recovery drill string apparatus, subterranean hydrocarbon recovery drilling methods, and subterranean hydrocarbon recovery methods. In one embodiment, a hydrocarbon recovery drill string apparatus includes an elongated assembly within which a rotatable drill rod is received. The assembly comprises a longitudinal axis, a drill rod entrance end, and a drill rod exit end. The assembly comprises a tailcuttings diverter pipe proximate the drill rod exit end, with the tailcuttings diverter pipe defining an initial fluid flow path of the tailcuttings from the longitudinal axis which is acute from the longitudinal axis. Other apparatus and method aspects are contemplated.

Abstract: According to some embodiments of the present disclosure, a method of configuring a blade of a drill bit comprises determining a first desired depth of cut for a first radial swath associated with a bit face of a drill bit. The first radial swath is associated with a first area of the bit face. The method further comprises identifying a first plurality of cutting elements located on the bit face. Each of the cutting elements includes at least a portion located within the first radial swath. The method additionally comprises configuring a first blade surface of a blade. The first blade surface is located within the first radial swath and configured based on the first desired depth of cut for the first radial swath. The blade surface is also configured based on each portion of the first plurality of cutting elements located within the first radial swath.

Abstract: Described are drilling subs that may be connected in a drill string for reducing the accumulation of debris on the exterior of the drill string or otherwise facilitating the return of drilling fluid during drilling operations. A plurality of radially spaced stabilizing blades protrude from an exterior surface of the drilling subs to define exterior flow channels therebetween through which drilling fluid returning to the surface may is directed. Diverting nozzle passages are provided that extend between an inner axial passage of the drilling subs and the exterior surface of the drilling subs. The diverting nozzle passages exhibit a radial spacing corresponding to a radial spacing of the exterior flow channels such that drilling fluid discharged from the diverting nozzle passages is directed toward the exterior flow channels.

Abstract: A drill bit made according to one embodiment includes a first member including one of a magnet and a coil, and a second member that moves relative to the first member, the second member including the other of the magnet and the coil, wherein the relative motion causes the generation of an electrical charge in the coil.

Abstract: A valve assembly includes a main housing having a central bore therethrough, an upper valve subassembly disposed within the main housing, the upper valve subassembly including an upper seat configured to contact a corresponding lower seat of a lower valve subassembly, and a flow diverter ring disposed proximate the upper seat of the upper valve subassembly, wherein the flow diverter ring is configured to direct a fluid flow radially away from the upper seat of the upper valve subassembly.

Abstract: A rock drilling rig and to a method for transmission thereof is provided. The rock drilling rig includes a carriage that is movable by drive equipment in a mine. The rock drilling rig includes a hydraulic drilling system for which pressure energy is generated by a hydraulic pump. The rock drilling rig is electrically driven and includes an electric motor that is connected to drive both the drive equipment and the hydraulic drilling system. The mechanical drive transmission included in the drive equipment and the hydraulic pump of the hydraulic drilling system may be connected and disconnected independently of one another by means of clutches.

Abstract: In accordance with some embodiments of the present disclosure, a method of configuring a depth of cut controller (DOCC) of a drill bit comprises determining a first desired depth of cut for a first radial swath associated with a bit face of a drill bit. The first radial swath is associated with a first area of the bit face. The method further comprises identifying a first plurality of cutting elements located on the bit face that each include at least a portion located within the first radial swath. The method additionally comprises configuring a first depth of cut controller (DOCC) for placement on the bit face within the first radial swath. The first depth of cut controller is configured based on the first desired depth of cut for the first radial swath and each portion of the first plurality of cutting elements located within the first radial swath.

Abstract: The present invention is directed to a fluid conveyed thruster for use in combination with a bottom hole assembly connected to a drill string during drilling operations. The fluid conveyed thruster comprises a continuous passage comprising a narrowed portion and an intersection. Fluid passing through the continuous passage of the fluid conveyed thruster accelerates as it passes through the narrowed portion and the intersection. The acceleration of fluid exiting the fluid conveyed thruster urges the tool forward and in turn urges the bottom hole assembly forward within a wellbore. The fluid conveyed thruster extends the reach of the bottom hole assembly and the drill string within the wellbore.

Abstract: In subterranean operations, additives used in treatment fluids such as drilling and cementing fluids include weighting agents; a method includes the steps of providing a treatment fluid for use in a subterranean formation comprising a weighting agent, the weighting agent comprising a micronized metal oxide particle and a polymer linked to the metal oxide particle, the method including introducing the treatment fluid into the subterranean formation.

Abstract: The invention relates to a rock drilling rig, a method for transfer drive of the rock drilling rig, and a speed controller. The rock drilling rig includes combustion-engine-free drive equipment which includes a plurality of electric components for implementation of the transfer drive. The control unit of the rock drilling rig includes load monitoring which monitors the load of the components during the transfer drive. Load monitoring allows the electric driving system to be intentionally overloaded for a period of time limited in advance. A user interface of the control unit comprises a speed controller whose control element has a first control range, where operation takes place in the rated load range, and a second control range, where operation takes place in the overload range.

Abstract: A non-rotating downhole sleeve adapted for open hole drilling and/or casing centralization. The sleeve includes a tubular body made of hard plastic with integrally formed helical blades positioned around its outer surface and an inner surface configuration which allows drilling fluid circulation to form a non-rotating fluid bearing between the sleeve and the drill pipe or casing. The helical blades reduce sliding and rotating torque while drilling, with minimal obstruction to drilling fluid passing through the borehole between the blades.

Abstract: In a dual-gradient drilling apparatus, a subsea solids processing unit includes a housing, a solids processing mechanism disposed in the housing between a drilling mud inlet and a drilling mud outlet, and a flushing mechanism configured to flush the solids processing mechanism with a flushing fluid. A subsea solids processing unit may be controlled by rotating the solids processing mechanism in a forward direction and increasing a drive torque when a measured speed of the solids processing mechanism is below a desired rotation speed. The desired rotation speed may be decreased when a measured torque exceeds a selected maximum and a rotation direction of the solids processing mechanism may be reversed when the measured speed falls below a selected minimum.

Abstract: Systems, devices and methods for the transmission of 1 kW or more of laser energy deep into the earth and for the suppression of associated nonlinear phenomena. Systems, devices and methods for the laser drilling of a borehole in the earth. These systems can deliver high power laser energy down a deep borehole, while maintaining the high power to advance such boreholes deep into the earth and at highly efficient advancement rates.

Abstract: A method for performing shale gas operation is disclosed. The method may include drilling a first well, performing a fracturing operation in the well, recovering shale gas from the first well, supplying at least part of the shale gas recovered from the well to an electrical generator, generating electricity using the generator, and transferring the generated electricity to drilling equipment used to drill a second well.

Abstract: A method of drilling into a geological region including a subsurface clathrate reservoir includes drilling a borehole into the geological region including the subsurface clathrate reservoir and dissociating at least a portion of the clathrate in a region near the borehole. After the dissociating, material within at least a portion of the region near the borehole in which the clathrate has been dissociated is compacted to form a compacted region at least partially surrounding the borehole within the clathrate reservoir. After the compacting, well casing is placed into the borehole within the compacted region and the well casing is cemented into the borehole in the compacted area.

Abstract: An apparatus for making a second borehole in the ground, a cross section of which second borehole partially intersects a cross section of an existing first borehole, includes a boring device and a guide device operatively connected to the boring device. The guide device includes a first guide element configured to interact with a first side of a wall of the existing first borehole facing the second borehole and a second guide element configured to interact with a second side of the existing first borehole remote from the second borehole. The guide device is configured to guide the boring device relative to the existing first borehole.

Abstract: An impulse-type underground supercharged jet drilling method and device is provided. The impulse-type underground supercharged jet drilling method uses up and down vibrations of a drill string or weight on bit variation during the drilling process, so that an upper joint connected to the drill string drives a housing and a supercharging cylinder block to move up and down relative to a supercharging piston, while the supercharging piston, a high pressure line, and a drive shaft disposed outside the high pressure line make a reciprocally retractable movement relative to the housing. As a result, some working fluid entering the supercharging cylinder block is intermittently supercharged, and discharged from a high pressure fluid passage disposed in the supercharging piston and the high pressure line. The present disclosure can effectively perform an underground supercharging to parts of the drilling fluid, thus improving the rock breaking efficiency and the drilling speed.

Abstract: A device is for a drilling rig for forming of a bore hole in a subterranean structure. The drilling rig comprises a first, top driven drilling machine arranged vertically displaceable along a guide track, where a second drilling machine is arranged between the first drilling machine and the bore hole, vertically displaceable along a guide track and provided with a rotary table arranged to be able to take the weight of a pipe string. A rotary drive unit is arranged for continuous rotation of the pipe string. A fluid chamber is arranged to, in a fluid communicating way, be able to connect a pipe string end portion with a drilling liquid plant. As the fluid chamber is provided with pipe string ports comprising means arranged to, in a fluid sealing way, be able to close the pipe string ports. A power tong is arranged for continuous rotation of an element connected to the pipe string, as the power tong is arranged in the fluid chamber.

Abstract: An apparatus for use in controlling first and second downhole tools includes a first cyclical indexing mechanism associated with a first downhole tool, and a second cyclical indexing mechanism associated with a second downhole tool, wherein the first indexing mechanism defines at least three sequential indexing positions within a cycle and the second indexing mechanism defines at least two sequential indexing positions within a cycle. The apparatus includes at least one actuator for actuating the first and second indexing mechanisms in response to a common stimulus to cause said first and second indexing mechanisms to advance between respective indexing positions so as to permit co-ordination of the operational states of the associated first and second downhole tools. The apparatus may be used for controlling first and second under reamers or for controlling an under reamer and a corresponding stabilizer.

Abstract: A system and method for reducing repairs to radial seals used in a rotating control head used while drilling is disclosed. Also, a system and method to detect leaks in the rotating control head and a latching system to latch the rotating control head to a housing is disclosed.

Abstract: Systems and methods for reducing the amount of torque transferred to the Bottom Hole Assembly and the drill string during drilling operations are disclosed. The drill string includes an optionally non-rotatable portion. A rotational hold down system is positioned at a first position on the drill string where it is not rotationally coupled to the drill string. The rotational hold down system is then moved to a second position on the drill string where it is rotationally coupled to the optionally non-rotatable portion of the drill string. In the second position, one or more bars on the rotational hold down system substantially prevent rotation of the optionally non-rotatable portion of the drill string.

Abstract: A downhole tool comprises a first connector sub coupled to an outer housing. A mandrel is disposed in the outer housing and is coupled to a mandrel. The second connector sub is slidably engaged with the outer housing so that torque loads are transferred from the first connector sub to the second connector sub through the outer housing independently of the mandrel.

Abstract: A method for maintaining pressure in a wellbore during drilling operations includes the steps of providing fluid from a reservoir through a drill string, circulating the fluid from the drill string to an annulus between the drill string and the wellbore, isolating pressure in the annulus, measuring pressure in the annulus, calculating a set point backpressure, applying back pressure to the annulus based on the set point back pressure, diverting fluid from the annulus to a controllable choke, controllably bleeding off pressurized fluid from the annulus, separating solids from the fluid, and directing the fluid back to the reservoir. An apparatus for maintaining pressure in a wellbore during drilling operations includes an adjustable choke for controllably bleeding off pressurized fluid from the wellbore annulus, a backpressure pump for applying a calculated set point backpressure, and a processor for controlling the adjustable choke and backpressure pump.

Abstract: A safety mechanism comprising: an obstructing member moveable between a first position where fluid flow is permitted, and a second position where fluid flow is restricted preferably blocked; a movement mechanism; and a wireless receiver, often an acoustic transceiver, adapted to receive a wireless signal; wherein the movement mechanism is operable to move the obstructing member from one of the first and second positions to the other of the first and second positions in response to a change in the signal being received by the wireless receiver. Embodiments of the invention thus provide a safety mechanism for a well such as a valve, packer, plug or sleeve, which can be operated wirelessly and so may allow operation of safety mechanisms in a well even when emergency situations have occurred.