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.

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.

A breaching device includes a body having a tamping material. The body has a target surface that is configured to face a target to be breached and a backing surface that is opposite the target surface. The tamping material is formed of gel and is configured to reflect an explosive force directed way from the target surface towards the target surface.

Provided is a detonation interrupt device. The detonation interrupt device, in one aspect, includes a first detonation train member positioned within a housing, and a mechanical member positioned proximate the first detonation train member. In this aspect, the mechanical member is movable between a first position physically separating the first detonation train member from a second detonation train member and thereby preventing the first detonation train member from detonating the second detonation train member, and a second position not physically separating the first detonation train member from the second detonation train member and thereby allowing the first detonation train member to detonate the second detonation train member, wherein the mechanical member is configured to automatically move from the first position to the second position as the housing and the second detonation train member move linearly with respect to each other.

Provided is a detonation interrupt device. The detonation interrupt device, in one aspect, includes a first detonation train member positioned within a housing, and a mechanical member positioned proximate the first detonation train member. In this aspect, the mechanical member is movable between a first position physically separating the first detonation train member from a second detonation train member and thereby preventing the first detonation train member from detonating the second detonation train member, and a second position not physically separating the first detonation train member from the second detonation train member and thereby allowing the first detonation train member to detonate the second detonation train member, wherein the mechanical member is configured to automatically move from the first position to the second position as the housing and the second detonation train member move linearly with respect to each other.

Provided is a detonation interrupt device. The detonation interrupt device, in one aspect, includes a first detonation train member positioned within a housing, and a mechanical member positioned proximate the first detonation train member. In this aspect, the mechanical member is movable between a first position physically separating the first detonation train member from a second detonation train member and thereby preventing the first detonation train member from detonating the second detonation train member, and a second position not physically separating the first detonation train member from the second detonation train member and thereby allowing the first detonation train member to detonate the second detonation train member, wherein the mechanical member is configured to automatically move from the first position to the second position as the housing and the second detonation train member move linearly with respect to each other.

Provided is a detonation interrupt device. The detonation interrupt device, in one aspect, includes a first detonation train member positioned within a housing, and a mechanical member positioned proximate the first detonation train member. In this aspect, the mechanical member is movable between a first position physically separating the first detonation train member from a second detonation train member and thereby preventing the first detonation train member from detonating the second detonation train member, and a second position not physically separating the first detonation train member from the second detonation train member and thereby allowing the first detonation train member to detonate the second detonation train member, wherein the mechanical member is configured to automatically move from the first position to the second position as the housing and the second detonation train member move linearly with respect to each other.

Provided is a method of operating a wireless blasting system in which a blasting device and electric detonators perform communications via a wireless network. Detonator reference times of the electric detonators are synchronized with a blasting reference time of the blasting device. Communication delay times of the electric detonators are calculated. The blasting device transmits a blasting command including a blasting time to the electric detonators. Whether or not the electric detonators are ready to perform blasting is determined by determining initial input states and detonator states of the electric detonators. When the electric detonators are ready, the electric detonators perform the blasting by counting ignition initialization times thereof in which the communication delay times are reflected.

Provided is a method of operating a wireless blasting system in which a blasting device and electric detonators perform communications via a wireless network. Detonator reference times of the electric detonators are synchronized with a blasting reference time of the blasting device. Communication delay times of the electric detonators are calculated. The blasting device transmits a blasting command including a blasting time to the electric detonators. Whether or not the electric detonators are ready to perform blasting is determined by determining initial input states and detonator states of the electric detonators. When the electric detonators are ready, the electric detonators perform the blasting by counting ignition initialization times thereof in which the communication delay times are reflected.

A detonator system wherein communication between detonators is achieved by using a transmitter coil in one detonator to modulate a magnetic field which is measured by means of a receiver coil in another detonator.