Sichuan University

Lingzhi Xie

Jianfeng Liu

Heping Xie

Ru Zhang

Yufei Wang

Feng Gao

Yang Ju

Yanan Gao

Fubao Zhou

Yingke Liu

A device for constructing an underground reservoir by dissolving limestone using carbon dioxide. The device includes a COstorage tank; an absorption tower; a decompression valve; a gas-liquid separator; a crystallizer; a vacuum pump; a buffer tank; a first booster pump; a second booster pump; and a third booster pump. The decompression valve is connected to a limestone layer, and is connected to the gas-liquid separator. The absorption tower is connected between the gas-liquid separator and the limestone layer.

Apparatus for making underground reservoir

A method for building an underground storehouse by dissolving limestone with carbon dioxide, the method comprising the following steps: a.) drilling two wells extending from the ground surface () to a limestone layer (), building a channel () allowing the two wells to communicate, and installing casing pipes () respectively in the two wells; b.) introducing COgas having at least 1 MPa of pressure into a COabsorbing solution having the same pressure to form a COsolution, flowing the COsolution into underground via the casing pipe () to react with the limestone to form a calcium bicarbonate solution, forming a cavern in the meanwhile, and discharging the calcium bicarbonate solution via the other casing pipe (); c.) decompressing the discharged calcium bicarbonate solution to decompose the calcium bicarbonate contained in the solution into CO, water and calcium carbonate, and recycling the separated COabsorption solution and the CO; repeating steps b.) and c.) until a cavern meeting design requirements is formed, and discharging the solution from the cavern to form the underground storehouse (). Also disclosed is a device for building an underground storehouse by dissolving limestone with carbon dioxide, the device comprising a COstorage tank (), an absorption tower (), a crystallizer (), a pressure relief valve (), a gas-liquid separator (), a vacuum pump (), a buffer () and booster pumps ().

Method and device for building underground storehouse by dissolving limestone with carbon dioxide

A pneumatic fracturing method for exploiting shale gas, the method including: 1) applying a compressed gas for a first period of time at a first pressure to a shale formation; 2) applying the compressed gas for a second period of time at a second pressure to the shale formation; and 3) repeating steps 1) and 2) to produce fissures in the shale formation. A temperature of the compressed gas is at least 80&#xb0; C. A maximum pressure of the compressed gas is at least 25 megapascal, and a minimum pressure of the compressed gas is between &#xbc; and &#x2153; of the maximum pressure.

Pneumatic fracturing method and system for exploiting shale gas

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Chengdu, China

Lingzhi Xie