Natural gas hydrate exploitation monitoring system and method based on ground well time-frequency electromagnetism

Abstract

The invention relates to a natural gas hydrate exploitation monitoring system based on ground well time-frequency electromagnetism; the system comprises armored time-frequency electromagnetism acquisition cables which are arranged on the seabed of a natural gas hydrate exploitation work area and under monitoring wells around an exploitation well, the armored time-frequency electromagnetism acquisition cables comprise acquisition short section pressure-bearing cabins, annular non-polarized electrodes are arranged outside the cables at equal intervals, and the armored time-frequency electromagnetic acquisition cables are connected with a time-frequency electromagnetic data receiving system; large-current power supply electrodes are respectively arranged at the periphery of the armored time-frequency electromagnetic acquisition cables at the seabed and are connected with a time-frequency electromagnetic controllable large-current emission source. According to the invention, the distribution of resistivity in an underground or underground reservoir of a natural gas hydrate exploitation work area and the change condition along with the exploitation process are monitored in real time, the development and application range in the reservoir is grasped in time, and the potential risk and possibility of leakage of the natural gas hydrate from the reservoir to the seabed are analyzed; and early warning information about possible occurrence of geological disasters such as seabed leakage in the natural gas hydrate exploitation process is provided.

Description

technical field [0001] The invention belongs to the field of real-time monitoring of the reservoir state and its stability during the exploitation of natural gas hydrate, and in particular relates to a natural gas hydrate exploitation monitoring system and method based on ground well time-frequency electromagnetics. Background technique [0002] Natural Gas Hydrate (Natural Gas Hydrate / Gas Hydrate) is combustible ice, which is an ice-like crystalline substance formed by natural gas and water under high pressure and low temperature conditions. "(Combustible ice), "solid gas" and "air ice". Natural gas hydrate is distributed in the deep sea or land permafrost. After burning, it only produces a small amount of carbon dioxide and water. The pollution is far less than coal, oil, etc., and its reserves are huge. Therefore, it is internationally recognized as an alternative energy source for oil. [0003] Traditional natural gas hydrate mining methods include thermal stimulation m...

AI Technical Summary

Problems solved by technology

If a large amount of natural gas hydrate is decomposed during the drilling process, it may also cause drilling deformation and increase the risk of offshore drilling platforms

[0011] Regardless of the traditional mining method or new mining method, the mining of gas hydrate below the seabed will change the structure of the underground gas hydrate reservoir. For example, the solid combustible ice in the rock pores of the gas hydrate reservoir will be gasified by the formation. Filling with water will weaken the structural strength of the natural gas hydrate reservoir rock, which may induce the generation of fractures or faults in the reservoir or the subsidence of the seabed, causing natural gas to flow along the fractures or faults extending to the seabed or along the gas hydrate production well The well wall leaks into the seawater, causing environmental damage or geological disasters

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