Abstract: Implementations described herein are directed to a pressure pulse well tool, which may include an upper valve assembly configured to move between a start position and a stop position in a housing. The pressure pulse well tool may also include an activation valve subassembly disposed within the upper valve assembly. The activation valve subassembly may be configured to restrict a fluid flow through the upper valve assembly and increase a fluid pressure across the upper valve assembly. The pressure pulse well tool may further include a lower valve assembly disposed inside the housing and configured to receive the fluid flow from the upper valve assembly. The lower valve assembly may be configured to separate from the upper valve assembly after the upper valve assembly reaches the stop position, causing the fluid flow to pass through the lower valve assembly and to decrease the fluid pressure across the upper valve assembly.

Abstract: Porous objects, such as porous balls, may be employed within telescoping devices to control proppant flowback through a completed well during production. The telescoping devices may connect a reservoir face to a production liner without perforating. Acid-soluble plugs initially disposed within the telescoping devices may provide enough resistance to enable the telescoping devices to extend out from the production liner under hydraulic pressure. The plugs may then be dissolved in an acidic solution, which may also be used as the hydraulic extension fluid. After the plugs are substantially removed from the telescoping devices, the reservoir may be hydraulically fractured using standard fracturing processes. The porous balls may then be inserted into the telescoping devices to block proppant used in the fracturing process from flowing out of the reservoir with the production fluids.

Abstract: The present invention regards a device designed for injection of fluids in a well bore, typically an offshore well bore for petroleum production and gas injection/gas lift system for fluid injection. The device comprises a outer hollow housing (1) with an internal body (2) moveable within the outer housing (1) with an internal bore (3) which in a first closed position is closed with a metal to metal seal system between the outer housing (1) and the internal body (2), which internal body (2) is operated by pressure differential across the internal body (2), where the internal body (2) is designed with slots (4) forming outlets of the internal bore (3) which in an open position of the device is positioned outside of the outer housing (1).

Abstract: An apparatus for isolating a first zone from a second zone in a subterranean wellbore. The apparatus includes an outer tubular and an inner tubular disposed within the outer tubular forming an annular flow path therebetween that is in fluid communication with the first zone. The inner tubular defines a central flow path that is in fluid communication with the second zone. A sleeve having at least one seal is positioned in the annular flow path and is axially movable relative to the inner and outer tubulars between a closed position wherein the seal engages the inner tubular and an open position wherein the seal engages the outer tubular. A mandrel is slidably disposed within the inner tubular and is coupled to the sleeve. The mandrel is operable to shift the sleeve between the open position and the closed position responsive to changes in pressure within the central flow path.

Abstract: The present invention relates to a downhole tool, comprising a hydraulic assembly, an arm assembly, the arm assembly comprising a wheel, a hydraulic motor for rotating the wheel, thereby driving the downhole tool in a forward direction, and a hydraulic pump unit for simultaneous generation of a first and a second pressurised fluid, characterised in that the arm assembly is movable between a retracted position and a projecting position in relation to the tool housing, and the downhole tool furthermore comprises an arm activation assembly for moving the arm assembly between the retracted position and the projecting position, and the hydraulic motor drives the downhole tool in the forward direction when the arm assembly is in the projecting position, the arm activation assembly being in fluid connection with the first pressurised fluid and the hydraulic motor being in fluid connection with the second pressurised fluid, a hydraulic control block for controlling the pressure of the first pressurised fluid having a

Abstract: A method of opening a conduit cemented in a subterranean well can include flowing a fluid through a passage in the well after the conduit is cemented in the well, and the conduit opening in response to the flow of the fluid through the passage. A well system can include a flow control device cemented in a wellbore, and a conduit positioned adjacent a passage of the flow control device, whereby the conduit opens in response to the passage being opened.

Abstract: Check valve assemblies operable to inject treatment fluids during stimulation operations are described. One check valve assembly includes a valve body defining an inlet, one or more discharge ports, and a cylindrical passageway fluidly communicating the inlet with the one or more discharge ports, the valve body further defining a valve body seat within the passageway. A valve cap is configured to be coupled to the valve body and defines an opening therein that fluidly communicates with the cylindrical passageway, the valve cap further providing a valve cap seat. A spherical piston is disposed within the passageway and movable between a closed configuration where the spherical piston engages the valve body seat and an open configuration where the spherical piston engages the valve cap seat and allows fluid communication between the inlet and the one or more discharge ports.

Abstract: A system for controlling flow in a wellbore uses a downhole flow control device positioned at a downhole location in the wellbore. The flow control device has a movable element for controlling a downhole fluid flow. In response to an applied pressure pulse, the movable element moves in finite increments from one position to another. In one embodiment, a hydraulic source generates a transmitted pressure pulse to the flow control device wherein the maximum pressure of a received pressure pulse downhole is sufficient to overcome a static friction force associated with the movable element, and wherein a minimum pressure of the received pressure pulse downhole is insufficient to overcome a dynamic friction force associated with the movable element.

Abstract: A method of actuating multiple valves in a well can include applying one or more pressure cycles to the valves without causing actuation of any of the valves, and then reducing pressure applied to the valves, thereby resetting a pressure cycle-responsive actuator of each valve. A pressure cycle-operated valve for use in a well can include a closure member, a piston which displaces in response to pressure applied to the valve, and a ratchet mechanism which controls relative displacement between the piston and the closure member. The ratchet mechanism may permit relative displacement while one or more pressure cycles are applied to the valve, and the ratchet mechanism may prevent relative displacement in response to a pressure sequence of: a) a reduction in pressure applied to the valve, b) a predetermined number of pressure cycles applied to the valve, and c) an increase in pressure applied to the valve.

Abstract: A method of actuating multiple valves in a well can include applying one or more pressure cycles to the valves without causing actuation of any of the valves, and then reducing pressure applied to the valves, thereby resetting a pressure cycle-responsive actuator of each valve. A pressure cycle-operated valve for use in a well can include a closure member, a piston which displaces in response to pressure applied to the valve, and a ratchet mechanism which controls relative displacement between the piston and the closure member. The ratchet mechanism may permit relative displacement while one or more pressure cycles are applied to the valve, and the ratchet mechanism may prevent relative displacement in response to a pressure sequence of: a) a reduction in pressure applied to the valve, b) a predetermined number of pressure cycles applied to the valve, and c) an increase in pressure applied to the valve.

Abstract: Hydraulic pulses are produced each time that a pulse valve interrupts the flow of a pressurized fluid through a conduit. The pulse valve includes an elongate housing having an inlet configured to couple to the conduit to receive the pressurized fluid, and an outlet configured to couple to one or more tools. In the housing, a valve assembly includes a poppet reciprocating between open and closed positions, and a poppet seat, in which the poppet closes to at least partially block the flow of pressurized fluid through the valve. A pilot within the poppet moves between disparate positions to modify fluid paths within the valve. When the valve is open, a relatively lower pressure is produced by a Venturi effect as the fluid flows through a throat in the poppet seat, to provide a differential pressure used to move the pilot and poppet. An optional bypass reduces the pulse amplitude.

Abstract: A downhole fluid flow control system includes a fluidic module (150) having a main fluid pathway (152), a valve (162) and a bridge network. The valve (162) has a first position wherein fluid flow through the main fluid pathway (152) is allowed and a second position wherein fluid flow through the main fluid pathway (152) is restricted. The bridge network has first and second branch fluid pathways (163, 164) each having a common fluid inlet (166, 168) and a common fluid outlet (170, 172) with the main fluid pathway (152) and each including two fluid flow resistors (174, 176, 180, 182) with a pressure output terminal (178, 184) positioned therebetween. In operation, the pressure difference between the pressure output terminals (178, 184) of the first and second branch fluid pathways (163, 164) shifts the valve (162) between the first and second positions.

Abstract: A downhole tool and method for performing to provide a flow path from an inner bore thereof to a wellbore annulus, wherein the flow path is provided upon the application of pressure.

Abstract: An apparatus for releasing gas pressure from a drill string includes a tubular housing having a circumferential sidewall, an axis, a first end, a second end and a central passage extending between the first end and the second end. A pressure member is positioned in the central passage along the axis of the housing. The pressure member is movable from a first position retracted within the housing to a second position extending past the second end of the housing. An actuator is provided to move the pressure member from the first position to the second position, where the pressure member exerts a force to move a valve member of a float valve to an open position, thereby allowing gas trapped in the drill string to flow through the central passage.

Abstract: A safety valve system for use in a subterranean well can include a safety valve protector connected downstream of a safety valve, whereby when closed the safety valve protector reduces a flow rate through the safety valve and prevents displacement of an object through the safety valve protector to the safety valve. Another safety valve system can include a safety valve protector which, when closed, reduces a flow rate through a safety valve, and the safety valve protector closes in response to the flow rate through the safety valve being above a predetermined level. In another safety valve system, each of the safety valve protector and the safety valve comprises an actuator, the actuators being connected by a line, and a signal transmitted by the line causes the safety valve protector actuator to close the safety valve protector, and then causes the safety valve actuator to close the safety valve.

Abstract: An embodiment of an assembly for setting an inflatable packer within a wellbore comprises a coiled tubing, an inflatable packer to be set in a wellbore, a back pressure valve, and a drain valve operable to allow fluid flow therepast and prevent inadvertent inflation of the inflatable packer.

Abstract: A control system for an annulus balanced subsurface safety valve. A system for operating a safety valve in a well includes a piston of the safety valve being responsive to displace due to a pressure differential between chambers exposed to the piston; and a valve controller which alternately exposes at least one of the chambers to pressure in an annulus surrounding the safety valve, and to pressure greater than that in the annulus. A method of operating a safety valve in a well includes the steps of: opening the safety valve by biasing a piston of the safety valve to displace in response to a pressure differential between a chamber exposed to pressure greater than well pressure, and another chamber exposed to well pressure; and closing the safety valve by exposing both of the chambers to the well pressure.

Abstract: A fracturing operation is done in open hole. The annular space is spanned by telescoping members that are located behind isolation valves. A given bank of telescoping members can be uncovered and the telescoping members extended to span the annular space and engage the formation in a sealing manner. Pressurized fracturing fluid can be pumped through the telescoped passages and the portion of the desired formation fractured. In a proper formation, cementing is not needed to maintain wellbore integrity. In formations that need annular space isolation, the string in a preferred embodiment can have an external material that grows to seal the annular space in lieu of a traditional cementing operation.

Abstract: A tubular actuator includes, a tubular, a support member disposed at the tubular, and a restrictor configured to pass a runnable member when unsupported by the support member and to prevent passage of the runnable member when supported by the support member. The restrictor is movable relative to the support member from an unsupported position to a supported position in response to pressure applied against the runnable member engaged with the restrictor according to a pressure versus time profile.

Abstract: The present invention generally relates to a valve assembly for use with a velocity string. The valve assembly is used during the snub-in operation and the snub-out operation of the velocity string. In one aspect, a valve for a velocity string is provided. The valve includes a body having a bore. The valve further includes a flapper member disposed in the body, wherein the flapper member includes a flapper that is movable between an opened position in which fluid flow is allowed to move through the bore in a first direction and a second direction, and a closed position in which fluid flow through the bore is blocked in the second direction. The valve further includes a sleeve member attached to the body by a releasable connection, wherein the sleeve member is configured to hold the flapper member in the opened position. The sleeve member is movable through the bore of the body upon release of the releasable connection.

Abstract: Disclosed are wellbore flow control devices and methods of using the same. One wellbore flow control device includes a sliding sleeve assembly defining a first entrance and a first exit and being movably arranged within a housing coupled to a wellbore pipe, the sliding sleeve assembly being fluidly communicable with one or more well screens via the first entrance and a first flow pathway, and a flow restricting assembly arranged within the housing and being fluidly communicable with the sliding sleeve assembly via the first exit and a second flow pathway, wherein the sliding sleeve assembly is movable between a first position, where the first entrance and first exit are blocked, and a second position, where the first entrance and first exit are open and allow fluid communication between the first and second flowpaths through the sliding sleeve assembly.

Abstract: A tubing conveyed tool for use in perforating a well bore utilizing abrasive perforating techniques. The perforating tool is particularly useful in non-vertical wells. The perforating tool is designed to permit running and setting a bridge plug, and then perforating the well bore without requiring the removal of the tool string. An eccentric weight bar can also be used to allow for directional perforating in non-vertical wells. The eccentric weight bar uses gravity to cause the bar to rotate to a predetermined position.

Abstract: To operate a device for use in a well, a counter mechanism is provided that is actuatable by pressure cycles to an active position that allows actuation of the device to a target state. A position retention mechanism is coupled to the counter mechanism to maintain the counter mechanism in the active position once the counter mechanism has been incremented by the pressure cycles to the active position.

Abstract: A downhole window tool includes an internal sleeve slidably received within an outer housing. The sleeve and outer housing may have windows that selectively align or the sleeve may move out of alignment with the window to allow fluid passage through a window. Sleeve movement within the housing is controlled by inserting a dart or plug in the interior of the sleeve to allow pressure to act on the plug or dart to move the sleeve a set amount to open the lateral window. A shear pin or other device may be used to control the amount of force necessary to open the window and further ensure unintended opening of the lateral window. The use of the removable dart or plug both prevents unintentional forces from opening the window and increases the amount of throughput through the sleeve as compared to when valve structure is installed within the tool.

Abstract: An apparatus that is usable with a well includes an operator and a generator. The operator is disposed in the well and configured to respond to a differential pressure between hydraulically isolated zones of the well to produce mechanical motion. The generator is disposed in the well to convert the mechanical motion into electricity. A method that is usable with a well is provided including maintaining hydraulic isolation between a first and second zone of a well. While maintaining the hydraulic isolation, the method further includes producing a mechanical motion in response to a differential pressure between the first and second zones and generating electricity in response to the mechanical motion.

Abstract: A tubular actuator includes, a restrictor disposed at a tubular that is engageably receptive to a runnable member run thereagainst as long as pressure remains above a latch pressure, the restrictor configured to allow passage of the runnable member after a delay at pressure equal to or below the latch pressure.

Abstract: A method of translating a member through a bore comprises moving fluid through a tubular member such as a drill string (2A), and generating impulses on the member by varying the passage of fluid through the member using a valve (60) which opens at a first rate and closes at a different second rate to urge the member to advance in a selected direction. The valve may close quickly and open slowly, or may close slowly and open quickly.

Abstract: A system and method enabling flow control with respect to a well related fluid. The system utilizes a choke manifold with a choke that can serve the function of both a fixed choke and an adjustable choke. The choke comprises components that are selectively adjusted to effectively provide differing calibrated flow paths along which the well related fluid flows when passing through the choke manifold. The choke manifold also may be combined with other system components in an efficient arrangement that facilitates handling of a variety of fluids, including multiphase fluids.

Abstract: The invention relates to device for controlling an inflatable tool used to treat a well or pipeline. The device, which is inserted between the outlet of a fluid supply pipe and the tool, comprises: a chamber communicating with the exterior through a tube and with the tool via a pipeline; and a piston mounted in said chamber, which, under the force of a spring, normally occupies a first position in which it seals the outlet of the pipe, the aforementioned tube then communicating with the pipeline. The pipeline is provided with at least one spring-loaded check valve which allows the passage of the pressurized fluid from the chamber to the tool when the pressure upstream of the valve exceeds a predetermined threshold value, which prevents the passage of the fluid in the opposite direction.

Abstract: Valves comprise a chamber having a piston disposed therein. One side of the piston defines a hydrostatic chamber in fluid communication with an outside environment, such as wellbore annulus, through a port. Operatively associated with the piston on the other side is a sleeve in sliding engagement with an inner mandrel. The inner mandrel comprises a port that is initially blocked by the sleeve. Upon an increase in pressure within the annulus, the piston is moved causing the port in the sleeve to align with the port in the inner mandrel thereby allowing fluid to flow from the annulus into the bore of the inner mandrel. As a result, fluid can be circulated through the valve, or pressure within the annulus can be reduced. A return member is operatively associated with the piston to urge the piston toward the closed position after pressure within the wellbore annulus is reduced.

Abstract: A method of operating an isolation valve can include continuously transmitting a signal to a detector section, and a control system operating an actuator in response to the detector section detecting cessation of the signal transmission. A well system can include an isolation valve which selectively permits and prevents fluid communication between sections of a wellbore, a remotely positioned signal transmitter, and the isolation valve including a control system which operates an actuator in response to detection of a signal by a detector section. Another well system can include an isolation valve interconnected in a tubular string, and the tubular string being cemented in a wellbore, with cement being disposed in an annulus formed radially between the isolation valve and the wellbore.

Abstract: A technique enables failsafe control over actuators used to actuate downhole tools. The technique may utilize a well system having a tool with an adjustable member. An actuation mechanism serves as a fail-as-is mechanism and works in cooperation with the adjustable member. The actuation member is shiftable upon receiving a predetermined input; however the actuation member does not move the adjustable member upon each shift. Once the actuation member has been shifted the requisite number of times to move the adjustable member to another position, at least one subsequent shift of the actuation member is not able to cause movement of the adjustable member. The result is a fail-as-is technique for ensuring the tool is not inadvertently actuated to another operational position.

Abstract: A radial flow valve includes a plurality of flow openings, a first piston and a second piston, the first and second pistons being independently actuable relative to one another, and a sleeve operatively coupled to the second piston, the sleeve adapted to be positioned so as to cover the plurality of flow openings. A method includes positioning a radial flow valve in a subterranean well bore having an upper zone pressure and a lower zone pressure, increase a pressure within the valve to a value above the upper zone pressure to release a first piston within the valve and, after releasing the first piston, reducing the pressure within the valve to a value that is less than the lower zone pressure to thereby cause a second piston within the valve to move and thereby permit fluid flow through the valve.

Abstract: A method, system and apparatus is provided for a partially retrievable safety valve to control a well. The method includes securing a normally closed valve in the well. The valve may be a self-equalizing flapper valve. Following this, an actuator system operable to open the valve is run into the well. The actuator system is removable from the well while the valve remains closed and secured in the well. A submersible pump and motor may be secured to the actuator system before the actuator system is run into the well. The submersible pump and motor are also removable from the well while the valve remains closed and secured in the well. Therefore the actuator system, submersible pump and motor can be replaced or redressed, while the valve remains closed, keeping the well under control at all times.

Abstract: A system for automating service operations at a well includes a service rig having at least one input device, an engine connected to an engine electronic control unit having a engine controller area network, a plurality of crown sheeves, a cable, an output device, a communication infrastructure, and at least one of a computer and an operator station; at least one remote server in electronic communication with the communication infrastructure; and a web portal in electronic communication with the at least one remote server.

Abstract: A method of drilling a well and installing a liner includes assembling concentric inner and outer strings of tubulars. A drill bit is located at the lower end of the inner string and a liner with a liner hanger makes up part of the outer string. The inner and outer strings may be rotated in unison to drill the well. A valve is located upstream of a liner hanger control tool used to release and set the liner hanger in the drill string. The valve comprises a ported sleeve that slides relative to a ported housing to meter flow from the interior of the drill string to the annular space. The redirected flow maintains a minimum flow rate in the annular space to prevent cuttings from settling on the control tool. A portion of the valve can further be used with a dart to manipulate downstream equipment.

Abstract: A circulating tool for use in drilling a bore hole, the tool including a plurality of pistons which, by the activation of fluid pressure, move between a first configuration in which a side port of the tool is covered by a piston and a second configuration in which two adjacent pistons separate across the port to allow fluid to jet from the port. In the first configuration, the tool has a continuous cylindrical bore to allow the passage of other tools through the tool, while a flapper valve closes the bore in the second configuration to achieve maximum jetting of fluid from the tool. A third or intermediate configuration is also described so that the tool is operable to switch multiple times between the configurations via an indexing mechanism.

Abstract: The present invention regards a device designed for injection of fluids in a well bore, typically an offshore well bore for petroleum production and gas injection/gas lift system for fluid injection. The device comprises a outer hollow housing (1) with an internal body (2) moveable within the outer housing (1) with an internal bore (3) which in a first closed position is closed with a metal to metal seal system between the outer housing (1) and the internal body (2), which internal body (2) is operated by pressure differential across the internal body (2), where the internal body (2) is designed with slots (4) forming outlets of the internal bore (3) which in an open position of the device is positioned outside of the outer housing (1).

Abstract: The present invention regards a device designed for injection of fluids in a well bore, typically an offshore well bore for petroleum production and gas injection/gas lift system for fluid injection. The device comprises a outer hollow housing (1) with an internal body (2) moveable within the outer housing (1) with an internal bore (3) which in a first closed position is closed with a metal to metal seal system between the outer housing (1) and the internal body (2), which internal body (2) is operated by pressure differential across the internal body (2), where the internal body (2) is designed with slots (4) forming outlets of the internal bore (3) which in an open position of the device leads to the outside of the outer housing (1).

Abstract: An actuator includes: a carrier including an axially elongated fluid conduit therein, the fluid conduit configured to received a ball therein; and an axially elongated ball receiving element, wherein one of the ball and the ball receiving element is configured to produce a magnetic field, and another of the ball and the ball receiving element includes an electrically conductive material, the ball and the ball receiving element configured so that the electrically conductive material is exposed to the magnetic field as the ball advances through the ball receiving element, and eddy currents are generated in the electrically conductive material that cause a repulsive force between the ball receiving element and the ball to at least one of reduce a velocity of the ball and actuate the ball receiving element.

Abstract: A method of actuating a well tool includes the steps of: increasing pressure in a fluid line of a fluid metering device; closing a pilot-operated valve in response to the pressure increasing step; and discharging a predetermined volume of fluid from the metering device in response to the pressure increasing and valve closing steps. A fluid metering device for a well tool includes a piston separating chambers; and a pilot-operated valve which selectively prevents fluid communication between the chambers in response to at least a predetermined pressure being applied to a fluid line of the metering device, and which permits fluid communication through the valve between the chambers in response to pressure in the fluid line being less than the predetermined pressure. A greater pressure may be applied to the fluid line to thereby bypass the metering device and allow fluid to discharge from the line.

Abstract: A formation saver sub or pump out sub incorporating an anti-surge feature. The sub includes a body, a mandrel, a piston (or an annulus fluid pressure chamber and a tubular pressure chamber), a sleeve, a spring, a releasable seat, and a plug. The plug and seat are released from the sub when one or more dogs releasably positioning the seat in the mandrel bore disengages from the seat due to a bleed off of fluid pressure in the well bore.

Abstract: A system and method for selectively stimulating a plurality of producing zones in a wellbore in oil and gas wells. The system includes a plurality of modules connected in a string that may be selectively actuated to stimulate a producing zone. Each module may be adapted to engage a tubing run ball seat. After installation of the string within the wellbore, a ball seat may be run into the well and positioned to selectively engage a desired module. The ball seat may be used to open a sleeve of the module permitting the stimulation of the producing zone. After stimulation of the producing zone, the ball seat may be removed from the wellbore rather than needing to drill out the ball seat. The sleeve may include a profile adapted to engage a shifting tool permitting the selective closure of the sleeve after stimulation of the producing zone.

Abstract: A fracturing operation is done in open hole. The annular space is spanned by telescoping members that are located behind isolation valves. A given bank of telescoping members can be uncovered and the telescoping members extended to span the annular space and engage the formation in a sealing manner. Pressurized fracturing fluid can be pumped through the telescoped passages and the portion of the desired formation fractured. In a proper formation, cementing is not needed to maintain wellbore integrity. In formations that need annular space isolation, the string in a preferred embodiment can have an external material that grows to seal the annular space in lieu of a traditional cementing operation.

Abstract: A tool that is usable in a well and may include an operator, a switch, a resilient device and an indexer. The switch may be configured to selectively communicate a first force to the operator, thereby actuating the tool. The resilient device may exert a second force. The indexer may cycle through a sequence of positions in response to alternating between the second force and a third force. The sequence includes a predetermined position configured to actuate the switch, thereby communicating the first force to the operator to actuate the tool.

Abstract: A technique is provided to facilitate use of a service tool at a downhole location. The service tool has different operational configurations that can be selected and used without moving the service string.

Abstract: A downhole valve comprises a tubular body and a valve member. The valve member is normally closed and in the closed position may prevent or restrict passage of a working fluid through the body. The valve member is movable to an open position, a first working fluid pressure differential being necessary to move the valve member from the closed position and a lower second working fluid pressure differential being necessary to maintain the valve member in the open position.

Abstract: An apparatus and method for the actuation of down-hole tools are provided. The down-hole tool that may be actuated and controlled using the apparatus and method may include a reamer, an adjustable gauge stabilizer, vertical steerable tools, rotary steerable tools, by-pass valves, packers, whipstocks, down hole valves, latch or release mechanisms and/or anchor mechanisms.

Abstract: Pressure cycle operated apparatus and methods. A method of actuating a firing head includes the steps of: reciprocably displacing an actuator piston of the firing head, the displacing step including the piston being alternately pressure balanced and unbalanced; and igniting a combustible material in response to the piston displacing step. A method of generating electricity includes: reciprocably displacing a piston, the displacing step including the piston being alternately pressure balanced and unbalanced; and generating electricity in response to the piston displacing step. A firing head includes an actuator piston separating at least two chambers; a check valve which permits one-way flow between the chambers; a flow restrictor which restricts flow between the chambers; a biasing device which biases the piston toward one of the chambers; and a firing pin releasing device which releases a firing pin in response to displacement of the piston.

Abstract: The present invention is to a tool for testing various zones in a well without having to remove the drill string containing the tool(s) from the well. Each of the individual fracture test tool has an internal passage that can be blocked by a ball bearing to close off the passage. Increased fluid pressure on the internal passage causes a valve body defining the passage to move to open windows in the tool. A collet reset tool is insertable through the passage to pull the valve body back into the run in position to close the windows without requiring the tools be raised to the surface to reset the fracture test tools.