Abstract: A system includes a casing string, a flow control apparatus, and a stinger. The flow control apparatus includes a tubular body, a float valve, and a disk. The tubular body has a conduit and a first end. The first end is connectable to the casing string. The float valve is fixed within the conduit of the tubular body and is configured to block flow in a first direction and allow flow in the second direction. The disk is fixed above the float valve and within the conduit of the tubular body. The disk is configured to prevent flow in the second direction until the disk is broken by a pre-determined force. The stinger is deployed in the casing string and applies the pre-determined force to the disk to allow a flow of the fluid, in the second direction, from the stinger to the annulus.

Abstract: Three different devices for increasing compatibility between older perforating gun systems and newer perforating gun systems are disclosed. One end cap adapted for use with a charge carrier includes a cutout for holding an addressable switch. Another end cap adapted for use with a charge carrier provides a route for transmission of electrical signals. A pin-to-pin tandem sub also provides a route for transmission of electrical signals between perforating guns.

Abstract: A safety mechanism and method for downhole perforating are disclosed. In one example, a mechanical firing head includes a firing pin carried on a pin carrier within a housing. The firing pin is movable from a retracted position to a firing position for striking an explosive initiator. A retention member retains the firing pin in the retracted position with the safety member in the armed position. A safety member is biased to a safety position that additionally blocks movement of the firing pin. The safety member is moveable to an armed position that unblocks movement of the firing pin in response to an arming pressure supplied to the housing bore. The retention member releases the firing pin in response to a firing pressure supplied to the housing in excess of the firing pressure.

Abstract: A perforating gun includes an outer sleeve included of a generally tubular wall structure having a peripheral surface around the outside, opposite ends thereof and a central passage therethrough extending from one end to the other end and further including a connection at each end to connect to other tools in a tool string wherein the outer sleeve is configured to carry the tensile and compressive forces imposable on the perforating gun as the perforating gun is deployed in the wellbore, and at least one pressure sealed perforating module installed within the central passage of the outer sleeve having a shaped charge sealed therein and wherein the installation of the pressure sealed perforating module within the outer sleeve is configured to substantially eliminate the transfer of tensile or compressive forces imposable on or by the tool string onto the at least one pressure sealed perforating module.

Abstract: A perforating gun deployable in a wellbore. The perforating gun may include an outer sleeve including a central passage, and a plurality of separate perforating modules receivable in the central passage of the outer sleeve. Each of the plurality of perforating modules of the perforating gun may include a carrier and a charge tube assembly received in the carrier, wherein the charge tube assembly incudes a shaped charge.

Abstract: A switch sub adapter configured to connect a switch sub to a perforating gun assembly. The switch sub adapter includes a tubular body having first threads that connect to the switch sub and second threads that connect to the perforating gun assembly; a first internal chamber formed at a first end of the adapter; a second internal chamber formed at a second end of the adapter; a conduit connecting the first internal chamber to the second internal chamber; and a dart having a tip located in the conduit and a base part located in the second internal chamber. The dart is formed from a compliant material that deforms in response to pressure resulting from detonation of charges associated with the perforating gun.

Abstract: A method for controlling a target switch assembly in a chain of switch assemblies includes distributing the chain of switch assemblies in a wellbore; placing a controller at a head of the wellbore; making a first decision, at the controller, to actuate a corresponding detonator of the target switch assembly; transmitting, from the controller to the target switch assembly, a fire command to activate the corresponding detonator; and making a second decision, locally, at the target switch assembly, to activate the detonator, after the fire command from the controller is received.

Abstract: A perforating gun apparatus comprising a bulkhead connector located between an upper gun body thread and lower gun body thread. The bulkhead connector has seals in sealing arrangement with an upper gun body and a lower gun body with a support sleeve in contact with an inner groove support shoulder on the lower gun body. The support sleeve is radially deformable into the inner groove by a shockwave produced by firing the charges in the lower gun section. The deformation of the support sleeve attenuates the impact of the shockwave on the threaded connection. The bulkhead connector isolates the threaded connection from the pressure spike. The deformed support sleeve attenuates the shockwave from the charges firing in the upper gun section and transfers the resultant force away from the threaded connection.

Abstract: A system and method to control wellbore pressure during perforating. The system comprises a carrier, a sensor, a pressure-altering device, and a processor in communication with the sensor. The sensor is configured to detect a stress wave propagating through the carrier before the arrival of a related pressure wave in the wellbore and generate a signal indicative of the detected stress wave. The pressure-altering device is actuatable to change the pressure in the wellbore. The processor is operable to analyze the signal from the sensor and control the pressure-altering device based on the detected stress wave to change the magnitude of the related pressure wave in the wellbore.

Abstract: A tool string includes a perforating gun including a signal conductor, a sub that includes a sub housing including a first bulkhead receptacle extending into the sub housing from a first end, a second bulkhead receptacle extending into the sub housing from a second end, and a switch receptacle positioned between the first bulkhead receptacle and the second bulkhead receptacle, a first bulkhead connector, and a second bulkhead connector, and a switch positionable in the switch receptacle, wherein the switch is configured to establish an electrical connection with the signal conductor of the perforating gun in response to coupling of the sub with the perforating gun, and wherein the switch receptacle is isolated from fluid pressure external of the switch receptacle when the first bulkhead connector is positioned in the first bulkhead receptacle and the second bulkhead connector is positioned in the second bulkhead receptacle.

Abstract: A detonator for use with perforating gun assemblies is presented. The detonator includes a shell including a main explosive load. The shell may include one or more openings. A non-mass explosive body is disposed in the shell, adjacent the main explosive load. The non-mass explosive body includes one or more channels extending therethrough. The detonator includes a plug adjacent the non-mass explosive body, and a PCB adjacent the plug to facilitate electrical communication with the detonator. The plug may include an elongated opening extending therethrough. The channels of the non-mass explosive body, in combination with at least one of the openings of the shell or the elongated openings of the plug, are configured to introduce fluids, such as wellbore fluids, into the non-mass explosive body to disable the detonator.

Abstract: An apparatus includes a radiation source to output radiation after power is supplied. The apparatus also includes a power source to supply power. The apparatus includes an ambient-activated switch electrically coupled between the radiation source and the power source. The ambient-activated switch is to switch to an open position while a value for an ambient characteristic for the ambient-activated switch is at an ambient level for a surface of the Earth. The ambient-activated switch is to switch to a closed position while the value for the ambient characteristic for the ambient-activated switch is at a downhole ambient level, wherein the ambient-activated switch is to electrically couple the power source to the radiation source while in the closed position.

Abstract: A first end of a conductive spring is embedded in a wall of a large chamber of a piston housing. The spring is held in tension by a second end of the spring being pinned against a bead contact by a trigger pin. The diameter of the piston and a tensile breaking strength of the trigger pin are selected so that the trigger pin is breakable and the tension in the spring is releasable upon the presence of a predetermined pressure difference between a pressure on the contact side of the piston and a pressure on the pinning side of the piston. Release of tension in the spring closes an electrical circuit.

Abstract: One or more burst disks, for isolating downhole communication between a tubular and a hydrocarbon-bearing formation, are fit with a shaped explosive charge. Detonation of the shaped charge is initiated by the rupture of the burst disk. In a system for stimulating the formation, one or more sets of two or more shaped charge, enhanced burst disks are located at a location along the tubular corresponding to a selected interval for stimulation. The enhanced burst disks can be fit with a chamber of known pressure for establishing a known and significant pressure differential across the burst disk for enabling substantially simultaneous rupture at the selected interval.

Abstract: Detonation of a perforating gun is initiated by engagement of the lower distal end of the gun assembly against a bottom hole bore plug. A fluid pressure actuated firing head is initiated by well fluid that is pressurized by a free piston having an integral rod projecting from the distal end of the gun assembly. The piston is displaced against a closed fluid volume when the projecting rod engages the bore plug.

Abstract: An explosive tool comprises a body structure, a charge, a detonator to ignite the charge via propagation of thermal energy, a pressure actuated safety to prevent propagation of sufficient thermal energy to ignite the charge when the pressure actuated safety is subjected to a surface pressure and to not prevent propagation of sufficient thermal energy to ignite the charge when the pressure actuated safety is subjected to at least a predefined pressure threshold, and a temperature actuated safety to prevent propagation of sufficient thermal energy to ignite the charge when the temperature actuated safety is subjected to a surface temperature and to not prevent propagation of sufficient thermal energy to ignite the charge when the temperature actuated safety is subjected to at least a predefined temperature threshold. The charge, the detonator, the pressure actuated safety, and the temperature actuated safety are contained within the body structure.

Abstract: A downhole tool assembly for use in a wellbore includes a tubular body carrying an explosive which is selectively detonated to create a dynamic underbalance or overbalance effect in the wellbore. The tubular body has opposite ends provided with plug assemblies including plug elements movable between a normally collapsed state and an actuable expanded state. The plug elements are adapted to be actuated to the expanded state between the tubular body and an outer extent of the wellbore before the creation of the dynamic underbalance or overbalance effect to isolate a discrete segment of the wellbore to which the dynamic underbalance or overbalance effect is confined.

Abstract: A ballistic transfer delay device and method of use. The ballistic transfer delay device does not include a firing pin and it is not pressure initiated. The device comprises a time delay fuse, a through-bulkhead initiator to initiate the time delay fuse, and an output booster to ballistically transfer the energy from the initiated time delay fuse.

Abstract: A wellbore apparatus includes a connector sub assembly having a body, the body having a first end adapted to couple to a first perforating sub component and a second, axially opposed end adapted to couple to a second perforating sub component. The connector sub body defines a cavity proximate the second end of the connector sub body; and a flow path in fluid communication with the cavity and a location exterior to the wellbore apparatus. The apparatus includes a valve residing in the flow path and actuatable to block or allow fluid flow from the cavity, through the flow path, to the location exterior to the wellbore apparatus.

Abstract: An explosive tool comprises a body structure, a charge, a detonator to ignite the charge via propagation of thermal energy, a pressure actuated safety to prevent propagation of sufficient thermal energy to ignite the charge when the pressure actuated safety is subjected to a surface pressure and to not prevent propagation of sufficient thermal energy to ignite the charge when the pressure actuated safety is subjected to at least a predefined pressure threshold, and a temperature actuated safety to prevent propagation of sufficient thermal energy to ignite the charge when the temperature actuated safety is subjected to a surface temperature and to not prevent propagation of sufficient thermal energy to ignite the charge when the temperature actuated safety is subjected to at least a predefined temperature threshold. The charge, the detonator, the pressure actuated safety, and the temperature actuated safety are contained within the body structure.

Abstract: An interruption sub for a downhole tool the downhole tool activatable by detonation. The interruption sub includes a barrier movable between a biased closed position and an open position. Preventing ballistic transfer to the downhole tool in the closed position and allowing ballistic transfer to the downhole tool in the open position. A detonation path within the interruption sub, wherein the barrier is hydraulically or electronically movable from the closed position to the open position in response to at least one condition acceptable for ballistic transfer. Also included is a downhole tool activatable by detonation.

Abstract: An explosive tool is disclosed. The explosive tool comprises a body structure, a charge, a detonator to ignite the charge via propagation of thermal energy, a pressure actuated safety to prevent propagation of sufficient thermal energy to ignite the charge when the pressure actuated safety is subjected to a surface pressure and to not prevent propagation of sufficient thermal energy to ignite the charge when the pressure actuated safety is subjected to at least a predefined pressure threshold, and a temperature actuated safety to prevent propagation of sufficient thermal energy to ignite the charge when the temperature actuated safety is subjected to a surface temperature and to not prevent propagation of sufficient thermal energy to ignite the charge when the temperature actuated safety is subjected to at least a predefined temperature threshold. The charge, the detonator, the pressure actuated safety, and the temperature actuated safety are contained within the body structure.

Abstract: A wellbore apparatus includes a connector sub assembly having a body, the body having a first end adapted to couple to a first perforating sub component and a second, axially opposed end adapted to couple to a second perforating sub component. The connector sub body defines a cavity proximate the second end of the connector sub body; and a flow path in fluid communication with the cavity and a location exterior to the wellbore apparatus. The apparatus includes a valve residing in the flow path and actuatable to block or allow fluid flow from the cavity, through the flow path, to the location exterior to the wellbore apparatus.

Abstract: A method of perforating a well includes selecting a desired transient underbalanced condition, configuring a perforating gun string to achieve the transient underbalanced condition, deploying the perforating gun is a wellbore, and firing the perforating to achieve the transient underbalanced condition.

Abstract: A method comprises: a. determining a configuration of a gun string, b. determining, by a computer, a pressure transient at a location in a wellbore, c. comparing the one or more pressures with the one or more pressure thresholds at the location, and d. perforating the wellbore with the gun string using the determined configuration of the gun string when the one or more pressures meet the one or more pressure thresholds at the location. The location in the wellbore has one or more pressure thresholds, and the pressure transient comprises one or more pressures.

Abstract: An explosive tool is disclosed. The explosive tool comprises a body structure, a charge, a detonator to ignite the charge via propagation of thermal energy, a pressure actuated safety to prevent propagation of sufficient thermal energy to ignite the charge when the pressure actuated safety is subjected to a surface pressure and to not prevent propagation of sufficient thermal energy to ignite the charge when the pressure actuated safety is subjected to at least a predefined pressure threshold, and a temperature actuated safety to prevent propagation of sufficient thermal energy to ignite the charge when the temperature actuated safety is subjected to a surface temperature and to not prevent propagation of sufficient thermal energy to ignite the charge when the temperature actuated safety is subjected to at least a predefined temperature threshold. The charge, the detonator, the pressure actuated safety, and the temperature actuated safety are contained within the body structure.

Abstract: An apparatus string for use in a wellbore has a plurality of activation modules having first and second ends and containing devices to be activated/initiated downhole. An apparatus string also has a plurality of initiator modules where at least initiator is operatively connected to each activation module and is addressable. Each initiator module may have a safety initiator which when the initiator module is addressed initiates the firing of the shaped charges in the gun module to which it is operatively connected. A wireless transmitter is operatively connected in and integral to the apparatus string for use in transmitting signals to address any initiator module in the apparatus string.

Abstract: A wellbore tool string includes a perforating gun having a plurality of explosive perforating charges and a shock mitigation tool. The shock mitigation tool including a tubular body having a top end, a bottom end, and a chamber; a barrier disposed proximate the bottom end in communication with the chamber; and a plurality of actuators connected with the body proximate to the top end of the body, each actuator opening a port in the body providing fluid communication with the chamber when the plurality of actuators are activated.

Abstract: An explosive tool is disclosed. The explosive tool comprises a body structure, a charge, a detonator to ignite the charge via propagation of thermal energy, a pressure actuated safety to prevent propagation of sufficient thermal energy to ignite the charge when the pressure actuated safety is subjected to a surface pressure and to not prevent propagation of sufficient thermal energy to ignite the charge when the pressure actuated safety is subjected to at least a predefined pressure threshold, and a temperature actuated safety to prevent propagation of sufficient thermal energy to ignite the charge when the temperature actuated safety is subjected to a surface temperature and to not prevent propagation of sufficient thermal energy to ignite the charge when the temperature actuated safety is subjected to at least a predefined temperature threshold. The charge, the detonator, the pressure actuated safety, and the temperature actuated safety are contained within the body structure.

Abstract: A downhole oilfield completion method comprises determining a surge profile for a wellbore and assembling a downhole completion tool having an interior surge volume and comprising a surge attenuation system operable to reduce a surge of the downhole completion tool based at least in part on the surge profile. The method also comprises running the downhole completion tool into the wellbore and surging the wellbore by admitting wellbore fluid into the interior surge volume, the surge reduced at least in part by the surge attenuation system.

Abstract: Electronic time delay apparatuses and methods of use are disclosed. An explosive or propellant system, which may be configured as a well perforating system includes an electronic time delay assembly comprising an input subassembly, an electronic time delay circuit, and an output subassembly. The input subassembly is activated by an external stimulus, wherein an element is displaced to activate an electronic time delay circuit. The electronic time delay circuit comprises a time delay device coupled with a voltage firing circuit. The electronic time delay circuit counts a time delay, and, upon completion, raises a voltage until a threshold firing voltage is exceeded. Upon exceeding the threshold firing voltage, a voltage trigger switch will break down to transfer energy to an electric initiator to initiate an explosive booster within the output subassembly.

Abstract: An underbalanced perforating system is disclosed for use in openhole completions to maximize the wellbore and matrix cleanup efficiency, to connect natural fracture patterns, and/or to enable application of new drilling fluid technology in difficult subsurface environments. The perforating system can be used for any hydrocarbon bearing formations with any lithology.

Abstract: A downhole oilfield completion method comprises determining a surge profile for a wellbore and assembling a downhole completion tool having an interior surge volume and comprising a surge attenuation system operable to reduce a surge of the downhole completion tool based at least in part on the surge profile. The method also comprises running the downhole completion tool into the wellbore and surging the wellbore by admitting wellbore fluid into the interior surge volume, the surge reduced at least in part by the surge attenuation system.

Abstract: An underbalanced perforating system is disclosed for use in openhole completions to maximize the wellbore and matrix cleanup efficiency, to connect natural fracture patterns, and/or to enable application of new drilling fluid technology in difficult subsurface environments. The perforating system can be used for any hydrocarbon bearing formations with any lithology.

Abstract: A perforating gun system having a relief system for relieving high pressure during unexpected high temperature or situations that may produce rupture of the gun body. The relief system may be responsive either to high temperatures as well as high pressures. In the high temperature situation, the relief system has a fuseable link that melts thereby allowing movement of a piston to open vent communication between the inside of a gun body in the ambient conditions. Similarly, a pressure device includes a piston responsive to pressure that moves under high pressure within the gun body thereby exposing a port enabling communication between the inside of the gun body and the ambient conditions.

Abstract: Electronic time delay apparatuses and methods of use are disclosed. An explosive or propellant system, which may be configured as a well perforating system includes an electronic time delay assembly comprising an input subassembly, an electronic time delay circuit, and an output subassembly. The input subassembly is activated by an external stimulus, wherein an element is displaced to activate an electronic time delay circuit. The electronic time delay circuit comprises a time delay device coupled with a voltage firing circuit. The electronic time delay circuit counts a time delay, and, upon completion, raises a voltage until a threshold firing voltage is exceeded. Upon exceeding the threshold firing voltage, a voltage trigger switch will break down to transfer energy to an electric initiator to initiate an explosive booster within the output subassembly.

Abstract: A buffering device for use in conjunction with a downhole tool string, wherein the tool string includes a ballistics device. The buffering device includes a mandrel attached within a tool string and proximate to the ballistics device. An anchor is disposed on the mandrel and a disk plate is coaxially placed on the mandrel that is slideable thereon. The disk plate is proximate to the ballistic device. A resilient member, such as a spring, is coaxially placed on the mandrel between the disk plate and the anchor. The pressure wave produced by activation of the ballistic device pushes the disk plate toward the anchor and compresses the spring there between. Since the disk plate extends outward into sealing contact with casing lining the wellbore, compression of the spring dissipates energy waves produced by activation of the ballistic device.

Abstract: A method is described for detonation of a blasting charge in a fluid environment and which is placed inside a hollow body, such as in an ignition pellet. The method is characterised in that an ignition pellet is used, which is arranged to be deformed under the influence of a number of alterations or pulsations between high and low pressure in the surrounding fluid environment, with the detonation triggering unit inside the body being activated at the subsequent contact with the fluid environment as a consequence of the pellet being deformed. In rupturing, external fluid at overpressure is released into the cylinder and drives a firing pin against a detonating cartridge. A device for an ignition pellet is also described.

Abstract: A perforating gun connector comprising a first and second section connected together on one end. The two sections of the perforating gun connector that couple together are correspondingly tapered so that one end of one connector is tapered and fits into the corresponding tapered hollowed section of one end of the other section. The present invention also provides for the inclusion of shaped charges and booster charges within. Adjacent the charges are sealing bulkheads.

Abstract: An explosive device includes a housing, and at least one of an initiator and an explosive in the housing. The at least one of the initiator and explosive are activatable in response to stimulus from a control line. A monitor in the housing monitors a state of the stimulus to enable determination of a status of the explosive device.

Abstract: Safety apparatus is disclosed for providing ballistic train interruption in a perforating system. The safety apparatus comprises a generally tubular shaped housing having first and second ends which are fabricated to permit the housing to be positioned at any location in the perforating system. The apparatus comprises first and second ballistic sections in the housing and a third ballistic section which is rotatably mounted in the housing to move between a disarmed position and an armed position based on downhole pressure. Upon retrieval of the perforating system from the wellbore, the safety apparatus functions to return a third ballistic section to its disarmed position. Additionally, apparatus is provided to permanently disable the third ballistic section to insure that no inadvertent detonation of the guns occurs when retrieving the system from a wellbore.

Abstract: A perforating safety system. A perforating safety system includes a detonation transfer interrupter with a device which decreases an axial separation between detonation transfer components after installation of the interrupter in the well. Another perforating safety system includes a perforating gun and firing head installed together in the well, and an interrupter having a device which increases a separation between detonation transfer components in the well to thereby prevent transfer of detonation from the firing head to the perforating gun. Yet another perforating safety system includes a firing head positioned at a distal end of a perforating assembly when installed in the well, and an interrupter having a device which decreases a separation between detonation transfer components after installation of the interrupter in the well.

Abstract: A well treatment system of the present invention includes a housing forming a sealed surge chamber, and a surge charge disposed within the sealed surge chamber, wherein the surge charge is adapted upon activation to penetrate the housing and to not penetrate material exterior of the housing. Fluid communication is created between the surge chamber and the wellbore when the housing is penetrated by the surge charge. The penetration permits wellbore fluid to flow quickly into the surge chamber. Fluid flow into the surge chamber may enhance a surge of flow from the formation into the wellbore.

Abstract: A method and apparatus for use in a wellbore includes running a tool string to an interval of the wellbore, and activating a first component in the tool string to create a transient underbalance pressure condition in the wellbore interval. Additionally, a second component in the tool string is activated to create a transient overbalance pressure condition in the wellbore interval, or vice versa.

Abstract: A system and method of damping fluid pressure waves in a subterranean well. In a described embodiment, pressure waves are damped by positioning a dampener in the well during a perforating operation. The dampener may attenuate the pressure waves by absorbing the pressure waves, flowing the pressure waves through viscously damping material, generating complementary pressure waves, changing a material phase, or by a combination of these methods.

Abstract: An apparatus and method includes positioning a string in a wellbore, the string having a surge chamber. A closure member is provided below the well surface, with the surge chamber defined at least in part by the closure member. At least one port to the chamber is opened to create a fluid surge into the surge chamber and a local low pressure condition in a wellbore region.

Abstract: An apparatus and method is provided to reduce interference resulting from activation of explosive devices. To reduce interference, one or more shock impeding elements are placed proximal one or more explosives to impede propagation of shock caused by detonation of the explosives. The shock impeding elements include a porous material, such as a porous liquid or solid.

Abstract: An apparatus and method of perforating and surging a section of the wellbore includes running a perforating gun into the well on a string having an isolation valve above the perforating gun, closing the valve, and perforating the well with the isolation valve closed so that the formation is isolated from the well surface. An underbalance pressure is provided above the isolation valve, and then, the isolation valve is opened to surge the formation.

Abstract: A firing head for a perforating gun includes a detonating block having a first end and a second end, with the second end being structured and arranged so as to be located adjacent to a detonation material. A central passage extends through the detonating block from the first end to the second end. A detonator is located and restrained in the passage so as to be adjacent to the detonating material. At least one venting passage extends from the central passage to an exterior of the detonating block.

Abstract: A system for unloading fluids from a generally upright tubular member of a wellbore wherein a combustible fuel cell can be placed in the tubular member below the fluid and ignited to generate gasses. The gasses generated by the burning of the fuel cell can be used to force at least a portion of the fluid upward out of the tubular member.