Patent ID: 11952869
Assignee: CHINA UNIVERSITY OF PETROLEUM (EAST CHINA)
Field: Civil engineering (Other fields)
Classification: CPC E | IPC E

Claim 6:
7. The high-efficiency yield-increasing exploitation method for the natural gas hydrates according to claim 6, wherein in step (iii), the pressure distributed in the reservoirs is reduced by controlling a pressure decay amplitude at the bottoms of the second horizontal well and the third horizontal well, so that the natural gas hydrates in the reservoirs are decomposed into gases and water, and meanwhile, and the gases flow into the second horizontal well and the third horizontal well under a differential pressure for recovery; and
a relationship between absorption of heat from the decomposition of the hydrates and a heat transfer around the reservoirs is coordinated by controlling the bottom pore pressure of the second horizontal well and the third horizontal well with a multi-stage step-by-step depressurization strategy, that is, the pressure decay amplitude at the bottoms of the wells is reduced after the bottom pore pressure is reduced to a hydrate phase equilibrium condition in decomposition, and with every 0.5 MPa of the bottom pore pressure declining, a bottom pore pressure value is maintained until a gas recovery rate declines significantly before the depressurization of the next step.