An explosive system for fracturing an underground geologic formation adjacent to a wellbore can comprise a plurality of explosive units comprising an explosive material contained within the casing, and detonation control modules electrically coupled to the plurality of explosive units and configured to cause a power pulse to be transmitted to at least one detonator of at least one of the plurality of explosive units for detonation of the explosive material. The explosive units are configured to be positioned within a wellbore in spaced apart positions relative to one another along a string with the detonation control modules positioned adjacent to the plurality of explosive units in the wellbore, such that the axial positions of the explosive units relative to the wellbore are at least partially based on geologic properties of the geologic formation adjacent the wellbore.

A catalytic burner with electric start is provided. The method of using the catalytic burner comprises an electric-start device that may actuated via a switch or remotely via radio signal.

A catalytic burner with electric start is provided. The method of using the catalytic burner comprises an electric-start device that may actuated via a switch or remotely via radio signal.

An explosive system for fracturing an underground geologic formation adjacent to a wellbore can comprise a plurality of explosive units comprising an explosive material contained within the casing, and detonation control modules electrically coupled to the plurality of explosive units and configured to cause a power pulse to be transmitted to at least one detonator of at least one of the plurality of explosive units for detonation of the explosive material. The explosive units are configured to be positioned within a wellbore in spaced apart positions relative to one another along a string with the detonation control modules positioned adjacent to the plurality of explosive units in the wellbore, such that the axial positions of the explosive units relative to the wellbore are at least partially based on geologic properties of the geologic formation adjacent the wellbore.

A heating apparatus may include a control valve assembly. A control valve assembly can have a housing and a valve body positioned within the housing. The housing can define an inlet and first and second outlets. The control valve assembly can also include an igniter having a sensor for firing an electrode. An extension can be used to activate the sensor and to thereby activate the igniter.

A heating apparatus may include a control valve assembly. A control valve assembly can have a housing and a valve body positioned within the housing. The housing can define an inlet and first and second outlets. The control valve assembly can also include an igniter having a sensor for firing an electrode. An extension can be used to activate the sensor and to thereby activate the igniter.

Detonation control modules and detonation control circuits are provided herein. A trigger input signal can cause a detonation control module to trigger a detonator. A detonation control module can include a timing circuit, a light-producing diode such as a laser diode, an optically triggered diode, and a high-voltage capacitor. The trigger input signal can activate the timing circuit. The timing circuit can control activation of the light-producing diode. Activation of the light-producing diode illuminates and activates the optically triggered diode. The optically triggered diode can be coupled between the high-voltage capacitor and the detonator. Activation of the optically triggered diode causes a power pulse to be released from the high-voltage capacitor that triggers the detonator.

A method and an unmanned aerial vehicle for identifying and remediating a gas leak. The method includes flying the unmanned aerial vehicle towards a possible location of the gas leak, then detecting a first condition indicative of the gas leak with a first sensor and sensing environmental conditions near the gas leak with an environmental sensor. The method includes receiving, by a controller, a signal representing the first condition indicative of the gas leak and a signal representing the environmental conditions. The method includes determining, based on the first condition indicative of the gas leak and the environmental conditions near the gas leak, a flight plan including an ignition zone. The method includes positioning, based on the flight plan, the unmanned aerial vehicle relative to the ignition zone and discharging, by an ignition mechanism, an ignition source into the gas leak to ignite the gas leak.

A method and an unmanned aerial vehicle for identifying and remediating a gas leak. The method includes flying the unmanned aerial vehicle towards a possible location of the gas leak, then detecting a first condition indicative of the gas leak with a first sensor and sensing environmental conditions near the gas leak with an environmental sensor. The method includes receiving, by a controller, a signal representing the first condition indicative of the gas leak and a signal representing the environmental conditions. The method includes determining, based on the first condition indicative of the gas leak and the environmental conditions near the gas leak, a flight plan including an ignition zone. The method includes positioning, based on the flight plan, the unmanned aerial vehicle relative to the ignition zone and discharging, by an ignition mechanism, an ignition source into the gas leak to ignite the gas leak.