Fishbone Well Structure and Method for Exploiting Natural Gas Hydrate

Abstract

The invention relates to the field of energy exploitation, and discloses a fishbone well structure and method for exploiting natural gas hydrate. The fishbone well structure of the present invention injects carbon dioxide fracturing fluid into the area around the hydrate layer by using the fracturing well arranged in the hydrate layer to create fractures for the hydrate layer, and the formed fractures can Effectively improve the permeability of the hydrate layer, and make the carbon dioxide fracturing fluid infiltrate into the fracture, and promote the decomposition of natural gas hydrate; in addition, the present invention sets the production well outside the injection well, during the production process, the production well It can keep the injection well warm and reduce the heat loss of the injection fluid during the injection process. At the same time, the fluid in the injection well can also transfer heat to the decomposition products in the production well, preventing the secondary formation of hydrates and blocking the wellbore. Therefore, the fishbone well structure of the present invention has the advantages of improved reservoir permeability, fast production speed, small energy loss and high efficiency.

Description

technical field [0001] The invention relates to the field of energy exploitation, in particular to a fishbone well structure for exploiting natural gas hydrate and a method for exploiting natural gas hydrate. Background technique [0002] Natural gas hydrate has the characteristics of rich reserves, wide distribution, high energy density, and relatively clean after combustion. Various countries regard it as an environmentally friendly alternative to traditional fossil energy in the future. [0003] According to the phase equilibrium properties of hydrates, natural gas hydrate production methods including heat shock method, depressurization method, chemical agent injection method and carbon dioxide replacement method have been proposed successively. However, since gas hydrate usually occurs in silt, fine silt and mud shale, and its own ice crystal form will block the flow channels, the permeability of gas hydrate reservoirs is often poor. The heat transfer and conductivity ...

AI Technical Summary

Problems solved by technology

However, since gas hydrate usually occurs in silt, fine silt and mud shale, and its own ice crystal form will block the flow channels, the permeability of gas hydrate reservoirs is often poor. The heat transfer and conductivity are greatly limited, and there are problems such as slow mining speed, long cycle, large energy loss, and low efficiency.

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