Abstract: A downhole stimulation tool comprising an outer housing exhibiting apertures extending therethrough, opposing propellant structures within the outer housing, and at least one initiator adjacent each of the opposing propellant structures. Each of the opposing propellant structures comprise at least one higher combustion rate propellant region, and at least one lower combustion rate propellant region longitudinally adjacent the at least one higher combustion rate propellant region. Additional downhole stimulation tools and methods of stimulating a producing formation are also disclosed.

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 is to an electric initiator to initiate an explosive booster within the output subassembly.

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 is to an electric initiator to initiate an explosive booster within the output subassembly.

Abstract: Apparatus providing at least one high pressure fluid cutting jet and methods employing same. A gas generator powered by a combustible propellant supplies pressurized gas to propel a fluid through at least one nozzle to form a cutting jet suitable for cutting materials such as structural elements. Furthermore, nozzles may be configured to rotate in order to circumferentially sever a tubular structural element. Two or more fluid cutting jets may be configured to intersect, and may be configured to intersect proximate to at least a portion of the periphery of the tubular structural element to be severed.