Gas-exploitation method and system for natural gas hydrate exploitation

Abstract

The invention discloses a gas-exploitation method and system for natural gas hydrate exploitation. Natural gas hydrates are utilized to decompose the gas lift effect of released methane gas, a gas-water mixture at the well bottom of an exploitation well is conveyed to a sea surface platform through an ocean riser, and thus controllable flowing exploitation of the ocean natural gas hydrates is achieved; at the exploitation starting stage, through the gas stripping effect of externally-injected gas, the well bottom pressure is reduced, and thus the hydrates are decomposed; and at the flowing exploitation stage, flowing exploitation is achieved through the gas lift effect of the natural gas hydrate decomposing gas, through a seabed gas storage tank, the flowing speed is adjusted, and gas consumption is supplemented. The gas exploitation technique and equipment are simple, operation is convenient, energy consumption is low, seabed movable equipment is not needed, industrial and automatic production is easy to achieve, the blockage risk caused by forming of secondary hydrates in the ocean riser can be avoided effectively, and the application range is wide.

Description

technical field [0001] The invention belongs to the field of energy technology, and relates to a method for exploiting marine natural gas hydrates, in particular to a system and a control method for exploiting marine natural gas hydrates, producing gas, and transporting them. Background technique [0002] Natural Gas Hydrate (Natural Gas Hydrate, referred to as Gas Hydrate) is a non-stoichiometric, ice-like, cage-type crystalline compound formed by low-molecular-weight hydrocarbons in water and natural gas under low temperature and high pressure conditions. Natural gas hydrates are mainly methane hydrates, most of which occur in the seabed, which have the advantages of large reserves, wide distribution, shallow burial, high energy density, and no pollution and residue after combustion. The decomposition of methane hydrate per unit volume can produce 150-180 standard volumes of methane gas. It is estimated that the organic carbon stored in the form of natural gas hydrate on ...

AI Technical Summary

Problems solved by technology

These methods of gas production and transmission using subsea electric submersible pumps have large energy consumption, short operating life, and high mining costs.

Images