Plasma-pulse treatment technology for the advance degassing of coal seams
Plasma Pulse Treatment or PPT is a stimulation technique used to enhance the secondary
permeability of the target formation by creation of new micro fractures and opening of
existing ones. Deployed by standard wireline equipment, the Plasma Pulse Streamer
applies repeated plasma pulses to the target zone of the formation.
- Drilling vertical wells from the surface.
- Conducting logging in an open hole to clarify the depth and thickness of the coal seam.
- Conducting PPT in the interval of coal seam and, if necessary, in the enclosing rocks.
- Degassing: dispatching the downhole pumping equipment, extraction of liquid, bringing wells to a stable flow rate of methane and 24-hour monitoring.
- Wells are used for degassing in the dome of the collapse. By the beginning of the start of lava, the downhole pumping equipment is removed from the wells and the mining machinery is activated.
Vertical PPT instrument:
- Generates non-linear controlled and directed vibrations/pulses.
- Elastic vibrations generate plasma waves.
- Elastic vibrations persist post treatment.
- Operation duration < 24 hours.
How does it work?
- The generator placed in the target zone creates dense plasma. Pressure pulses open existing and create new microfractures, which enhances the permeability of the formation.
- The generator is capable of producing up to 2000 pluses in one run, causing significant impact on the mechanical integrity of the formation zone, thus creating microcracks.
- The electrodes places in the tool ionizes the wire, which acts as a source of plasma that creates a powerful impulse.
- The pulse characteristic can be optimized in accordance with the requirement and maximizing the impact on the formation.
Advance degassing of coal seams
Coal resources are well known for the Methane adsorption and entrapment properties. It is popularly known as Coal Bed Methane (CBM). CBM is formed during the process of coalification (transformation of plant material into coal).