SELF-ADVANCING MINING DEVICE AND MINING METHOD FOR MARINE NATURAL GAS HYDRATE

摘要

A self-advancing mining device and mining method for marine natural gas hydrate. The mining device comprises a self-advancing structure (1), a sand control device (2) and a gas-liquid lifting system; the self-advancing structure (1) is a gravity anchor, and the sand control device (2) and the gas-liquid lifting system are mounted on the self-advancing structure (1); at least one cavity (21) is formed between the self-advancing structure (1) and the sand control device (2), and the cavity (21) is communicated with at least one channel; the sand control device (2) allows liquid and gas to pass through and into the cavity (21), and filters sand; and the gas-liquid lifting system comprises at least one lifting power device (31), the gas-liquid lifting system has one end connected to the cavity (21), and the other end transports the liquid and gas outwardly by means of a pipeline. Said device performs mining without well drilling, and the self-advancing structure (1) impacts into a natural gas hydrate reservoir or a natural gas hydrate reservoir underlying free gas layer, so that depressurizing mining and recovery of a mining system can be achieved, and the mining cost of natural gas hydrate can be greatly reduced.