A method of removing material from a target is described. The method comprises the steps of providing a tool, the tool having at least one propellant source; pressurising the tool to a pressure higher than the environmental pressure; igniting at least one of the propellant source(s) to form a combustion zone; and directing combustion products generated at the combustion zone along at least one tool flow path. The tool flow path(s) is selectively openable or closable, such that upon exiting the tool flow path(s) the combustion products interact with a target, the interaction causing material to be removed from the target.

A waveform energy generation system, the system including at least one joint of production casing, and one or more energy generators residing along the joint of production casing. The energy generators are configured to be in substantial mechanical contact with a subsurface formation within a wellbore. The energy generators may include either explosive devices or a piezo-electric material. The system also includes a signal transmission system. The signal transmission system is used to send control signals from the surface down to the energy generators for activation at the formation's resonant frequency. Methods of enhancing the permeability of a rock matrix within a subsurface formation using the wellbore as an energy generator are also provided.

A waveform energy generation system, the system including at least one joint of production casing, and one or more energy generators residing along the joint of production casing. The energy generators are configured to be in substantial mechanical contact with a subsurface formation within a wellbore. The energy generators may include either explosive devices or a piezo-electric material. The system also includes a signal transmission system. The signal transmission system is used to send control signals from the surface down to the energy generators for activation at the formation's resonant frequency. Methods of enhancing the permeability of a rock matrix within a subsurface formation using the wellbore as an energy generator are also provided.

A flow conveyed plugging device for use in a well, the device can include a body, and one or more lines extending outwardly from the body, each of the lines having a lateral dimension that is substantially smaller than a size of the body. A method of plugging an opening in a well can include deploying at least one flow conveyed plugging device into the well, the flow conveyed plugging device including a body and, extending outwardly from the body, at least one of the group consisting of: a) one or more fibers and b) one or more lines, the flow conveyed plugging device being conveyed by flow in the well into sealing engagement with the opening. Another flow conveyed plugging device can include a body, and fibers extending outwardly from the body. The flow conveyed plugging device degrades and thereby permits flow through an opening in the well.

A flow conveyed plugging device for use in a well, the device can include a body, and one or more lines extending outwardly from the body, each of the lines having a lateral dimension that is substantially smaller than a size of the body. A method of plugging an opening in a well can include deploying at least one flow conveyed plugging device into the well, the flow conveyed plugging device including a body and, extending outwardly from the body, at least one of the group consisting of: a) one or more fibers and b) one or more lines, the flow conveyed plugging device being conveyed by flow in the well into sealing engagement with the opening. Another flow conveyed plugging device can include a body, and fibers extending outwardly from the body. The flow conveyed plugging device degrades and thereby permits flow through an opening in the well.

A downhole sub has a cylindrical body and a sealing device disposed about the cylindrical body. The cylindrical body has a first fluid chamber configured to store a hydraulic fluid, a second fluid chamber configured to store a liquid energetic material, a piston slidably disposed between the first fluid chamber and the second fluid chamber, and an ignition unit. The sealing device has two annular pistons and two annular sealing rings. The sub is loaded with the liquid energetic material and lowered into a well casing installed in the subterranean formation. A section of the well casing having a plurality of perforations is sealed. The liquid energetic material in the downhole sub is injected into the subterranean formation through the plurality of perforations in the well casing and is detonated using the ignition unit in the downhole sub.

A downhole sub has a cylindrical body and a sealing device disposed about the cylindrical body. The cylindrical body has a first fluid chamber configured to store a hydraulic fluid, a second fluid chamber configured to store a liquid energetic material, a piston slidably disposed between the first fluid chamber and the second fluid chamber, and an ignition unit. The sealing device has two annular pistons and two annular sealing rings. The sub is loaded with the liquid energetic material and lowered into a well casing installed in the subterranean formation. A section of the well casing having a plurality of perforations is sealed. The liquid energetic material in the downhole sub is injected into the subterranean formation through the plurality of perforations in the well casing and is detonated using the ignition unit in the downhole sub.

A method and apparatus for acidizing and perforating simultaneously.

A method and apparatus for acidizing and perforating simultaneously.

A method, downhole tool, and system, of which the method includes deploying a perforation charge into a wellbore, signaling the perforation charge to detonate, deploying a cable into the wellbore, determining a fluid flow rate at a predetermined location in the wellbore using the cable, and determining whether the perforation charge detonated at the predetermined location based on the fluid flow rate.