Nuclear magnetic resonance-based combustible ice mining reservoir monitoring method

Abstract

The invention discloses a nuclear magnetic resonance-based combustible ice mining reservoir monitoring method. The nuclear magnetic resonance-based combustible ice mining reservoir monitoring method is mainly suitable for dynamically monitoring a state and pore structure change of combustible ice in a reservoir stratum in the mining process of a deep sea combustible ice reservoir stratum. The method comprises the following steps of firstly, drilling a detection drill hole downwards to a free gas reservoir through a sea surface operation platform, drilling samples of a combustible ice reservoir stratum and the free gas reservoir stratum for detection, and finding out parameters of the combustible ice reservoir, such as depth and thickness; injecting a horizontal well into the free gas reservoir stratum to conduct a combustible ice depressurization method for exploitation, performing real-time dynamic monitoring on the free gas reservoir stratum and the combustible ice reservoir stratum at different positions by using a nuclear magnetic resonance miniature sensor in the exploiting process to obtain the generation rate and spatial migration of methane and moisture at different positions of the reservoir stratum; and meanwhile, monitoring reservoir monitor settlement and the range and conducting early warning, and providing guidance for continuous and stable mining of the combustible ice. The nuclear magnetic resonance-based combustible ice mining reservoir monitoring method is simple, convenient, easy to operate, safe, reliable, high in accuracy and capable of achieving real-time monitoring and early warning in the deep sea combustible ice reservoir stratum exploitation process.

Description

technical field [0001] The invention relates to a nuclear magnetic resonance-based monitoring method for flammable ice mining reservoirs, which is especially suitable for real-time monitoring of the generation rate and space migration of methane and water during deep-sea flammable ice reservoir mining, and can monitor and warn reservoir settlement. Background technique [0002] Combustible ice, that is, natural gas hydrate, its molecular structure is CH 4 ·H 2 O, is a cage-like crystalline compound solid formed by the combination of methane and water under low temperature and high pressure conditions. At present, it is found that it is mainly distributed in the deep seabed of my country and has abundant reserves. According to the most conservative estimates, the total amount of methane stored in the global seabed combustible ice is about 180 million cubic meters, or about 11,000 tons, which is equivalent to more than twice the reserves of traditional fossil energy (oil, coa...

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Problems solved by technology

[0004] At present, the monitoring in the mining process of combustible ice is realized by adding some small sensors such as pressure, temperature and strain on the mining borehole. Therefore, the detection range is small and the combustible ice reservoir cannot be monitored, and it is impossible to Combustible ice mining provides reliable guidance

In recent years, nuclear magnetic resonance (NMR) technology has been widely used to measure methane H signal and water signal. However, the engineering application based on NMR technology is currently only focused on the advanced water detection in tunnel construction, and cannot fully utilize the rapidity of NMR technology. Advantages of Monitoring Methane H Signal and Water Signal

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