The invention relates to a
microwave-assisted
supercritical carbon dioxide cyclic fracturing
system and a
microwave-assisted
supercritical carbon dioxide cyclic fracturing method. The
microwave-assisted
supercritical carbon dioxide cyclic fracturing
system comprises a
liquid carbon dioxide tank, a heater, a boosting pump, a fracturing
pipe, a return
pipe, a three-phase separator, an
air compressor and a cooler which form a loop to achieve supercritical
carbon dioxide cyclic fracturing, and a fracture network is formed in a
coal seam. According to the microwave-assisted supercritical
carbon dioxide cyclic fracturing method, the
coal seam and
carbon dioxide are subjected to microwave heating to ensure that the carbon dioxide is in the supercritical state for a long time, and
heat effect of microwave heating is capable of fracturing
coal masses, dredging pores and promoting gas
desorption. The microwave-assisted supercritical carbon dioxide cyclic fracturing
system and the microwave-assisted supercritical carbon dioxide cyclic fracturing method have the advantages that the supercritical carbon dioxide high in diffusivity is capable of going deep into coal
mass pores and fractures quite easily as well as dispelling gas; operation costs are reduced effectively and the construction technology is simplified effectively through cyclic fracturing; microwave
radiation is combined with supercritical carbon dioxide cyclic fracturing to increase
porosity and permeability of the coal seam greatly and promote gas
desorption, so that gas extraction effects are improved substantially, and the system and the method are highly practical in the field.