Abstract: A downhole explosive detonation assembly with a high voltage electro-explosive initiator having an input high voltage power supply with a low impedance shunting fuse, a flexible electrical link and a capacitor discharge unit. The explosive detonation assembly is adapted to detonate detonating cord from the side.

Abstract: A perforation test target is provided. The perforation test target includes a metal plate and a core sample adhered to the metal plate at one end. The perforation test target further including a first sleeve adhered to the core sample, where a flow impedance of each of a plurality of portions of the first sleeve is based on a predetermined impedance map.

Abstract: A downhole explosive detonation comprises a high voltage electro-explosive initiator comprising an input high voltage power supply with a low impedance shunting fuse, a flexible electrical link and a capacitor discharge unit. Explosive is initiated in a direction approximately parallel, or in another version perpendicular to the capacitor discharge unit. A unique configuration and construction of the assembly allows installation through a small service port in the gun housing structure for more efficient gun arming. A real time downhole voltage monitoring is described that transmits voltage readings to the surface during a firing sequence.

Abstract: A tool activation system and method includes receiving an authorization code of a user to verify access rights of a user to activate the tool. In one example, the authorization code is receive from a smart card. The environment around the tool, which can be in a wellbore, for example, is checked. In response to the authorization code and the checking of the environment, activation of the tool is enabled.

Abstract: A method and apparatus is described for modifying downhole wellbore pressure at the instant that an explosive event occurs. By a significant temporary reduction in wellbore pressure, for example, an explosive cutter will be able to cut through thicker pipe in a deep well with high hydrostatic pressure. A favorable transient wellbore pressure is achieved by the selective timing of implosion and explosion devices, to improve the performance of certain explosive tools when subsequently initiated, such as shaped charge explosive cutters, severing tools, setting tools and perforating guns. As part of the system, each implosion or explosion device is initiated by a detonator having a preprogrammed control unit with a preselected timing delay to take advantage of the temporarily lowered wellbore pressure.

Abstract: The pipe cutting capacity of an explosive pipe cutter may be improved by directing colliding shock fronts from opposite axial directions against a disc of metal having a shock impedance substantially corresponding to the shock impedance capacity of the explosive material.

Abstract: A perforation test target is provided. The perforation test target includes a metal plate and a core sample adhered to the metal plate at one end. The perforation test target further including a first sleeve adhered to the core sample, where a flow impedance of each of a plurality of portions of the first sleeve is based on a predetermined impedance map.

Abstract: A system for testing a core sample comprises a non-permeable sleeve configured to be placed over a core sample, a first pair of opposing actuators to apply opposing force to the non-permeable sleeve in a first axis normal to an axis of the core sample, a second pair of opposing actuators to apply opposing force to the non-permeable sleeve in a second axis normal to the axis of the core sample and normal to the first axis, a wellbore pressure reservoir to provide simulated wellbore pressure, and a formation pressure reservoir to provide simulated formation fluid pressure.

Abstract: The pipe cutting capacity of an explosive pipe cutter may be improved by directing colliding shock fronts from opposite axial directions against a disc of metal having a shock impedance substantially corresponding to the shock impedance capacity of the explosive material.

Abstract: A downhole explosive detonation comprises a high voltage electro-explosive initiator comprising an input high voltage power supply with a low impedance shunting fuse, a flexible electrical link and a capacitor discharge unit. Explosive is initiated in a direction approximately parallel, or in another version perpendicular to the capacitor discharge unit. A unique configuration and construction of the assembly allows installation through a small service port in the gun housing structure for more efficient gun arming. A real time downhole voltage monitoring is described that transmits voltage readings to the surface during a firing sequence.

Abstract: The pipe cutting capacity of an explosive pipe cutter may be improved by directing colliding shock fronts from opposite axial directions against a disc of metal having a shock impedance substantially corresponding to the shock impedance capacity of the explosive material.

Abstract: A method of testing a core sample is provided. The method comprises determining an impedance map, attaching a sleeve to the core sample, and measuring a flow performance of the core sample. An impedance of each of a plurality of portions of the sleeve is based on the impedance map.

Abstract: A downhole explosive detonation comprises a high voltage electro-explosive initiator comprising an input high voltage power supply with a low impedance shunting fuse, a flexible electrical link and a capacitor discharge unit. Explosive is initiated in a direction approximately parallel, or in another version perpendicular to the capacitor discharge unit. A unique configuration and construction of the assembly allows installation through a small service port in the gun housing structure for more efficient gun arming. A real time downhole voltage monitoring is described that transmits voltage readings to the surface during a firing sequence.

Abstract: Apparatus and methods for controlling and communicating with one or more tools in a downhole tool string including a tractor, an auxiliary tractor tool, a logging tool, a safety sub, a release mechanism, a unit containing sensors for monitoring downhole conditions, a setting tool, and a perforating gun. Also provided are apparatus and methods for controlling and communicating with one or more perforating guns, release devices, and explosive devices in a string to be lowered into a wellbore. Control and communication are accomplished by sending signals from the surface to control switches in the control units on the tool, with redundant switches for safety, to state machines in the respective control units, “each state machine returning a signal verifying switch status to the surface. Control and power functions are accomplished with voltage of different polarities for safety.

Abstract: Apparatus and methods for controlling and communicating with one or more tools in a downhole tool string including a tractor, an auxiliary tractor tool, a logging tool, a safety sub, a release mechanism, a unit containing sensors for monitoring downhole conditions, a setting tool, and a perforating gun. Control and communication are accomplished by sending signals from the surface to control switches in the control units on the tool, with redundant switches for safety, to state machines in the respective control units, each state machine returning a signal verifying switch status to the surface. The state machine need not return a signal including a unique identifier.

Abstract: Apparatus and methods for controlling and communicating with one or more tools in a downhole tool string including a tractor, an auxiliary tractor tool, a logging tool, a safety sub, a release mechanism, a unit containing sensors for monitoring downhole conditions, a setting tool, and a perforating gun. Control and communication are accomplished by sending signals from the surface to control switches in the control units on the tool, with redundant switches for safety, to state machines in the respective control units, each state machine returning a signal verifying switch status to the surface. The state machine need not return a signal including a unique identifier.

Abstract: A system for testing a core sample comprises a non-permeable sleeve configured to be placed over a core sample, a first pair of opposing actuators to apply opposing force to the non-permeable sleeve in a first axis normal to an axis of the core sample, a second pair of opposing actuators to apply opposing force to the non-permeable sleeve in a second axis normal to the axis of the core sample and normal to the first axis, a wellbore pressure reservoir to provide simulated wellbore pressure, and a formation pressure reservoir to provide simulated formation fluid pressure.

Abstract: Apparatus and methods for controlling and communicating with one or more tools in a downhole tool string including a tractor, an auxiliary tractor tool, a logging tool, a safety sub, a release mechanism, a unit containing sensors for monitoring downhole conditions, a setting tool, and a perforating gun. Also provided are apparatus and methods for controlling and communicating with one or more perforating guns, release devices, and explosive devices in a string to be lowered into a wellbore. Control and communication are accomplished by sending signals from the surface to control switches in the control units on the tool, with redundant switches for safety, to state machines in the respective control units, each state machine returning a signal verifying switch status to the surface. Control and power functions are accomplished with voltage of different polarities for safety.

Abstract: The pipe cutting capacity of an explosive pipe cutter may be improved by directing colliding shock fronts from opposite axial directions against a disc of metal having a shock impedance substantially corresponding to the shock impedance capacity of the explosive material

Abstract: A method of testing a core sample is provided. The method comprises determining an impedance map, attaching a sleeve to the core sample, and measuring a flow performance of the core sample. An impedance of each of a plurality of portions of the sleeve is based on the impedance map.