Application method of precise evaluation device for vertical content distribution of seabed hydrate reservoirs

Abstract

The invention relates to the determination of the content of seabed hydrate, in particular to a method for using a device for accurately evaluating the vertical content distribution of seabed hydrate reservoirs. Generate gaseous substances; open the directional guide channel corresponding to the working thermal excitation system in S2, so that the gaseous natural gas hydrate generated in this layer enters the screw-in long casing through the directional guide channel; the gas collection system hydrates the gaseous natural gas Collect objects: through the optical ranging unit and resistivity unit, analyze and record the composition and content in the box; repeat the actions of S4 and S5 until the end of a collection cycle; data processing and analysis. It realizes the accurate assessment of the vertical content distribution of seabed hydrate.

Description

technical field [0001] The invention relates to the content determination of seabed hydrate, in particular to a method for using a device for accurately evaluating the vertical content distribution of a seabed hydrate reservoir. Background technique [0002] Knowing the location and distribution characteristics of natural gas hydrates is very important, and it is also the first premise of all subsequent work. The current popular detection technologies in the world mainly include acoustic detection technology, time domain reflection technology, impedance detection technology, TDR and other test joint detection technologies. The most important and effective detection method at this stage is to use the detection of the distribution of the cold spring plume in the seawater to further complete the determination of the hydrate distribution area and the development of the hydrate. [0003] Theory and practice have proved that the sea area sedimentary layer with a water depth of mo...

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Problems solved by technology

[0004] At present, the mainstream way to detect the distribution and content of seabed gas hydrate reservoirs is mainly to rely on geophysical monitoring of cold seep plumes. First, determine the distribution range of hydrates, and then use marine geophysical prospecting methods to conduct large-scale assessment. After the assessment is completed, Due to the shortcomings of inaccurate geophysical detection methods, relying on manual experience, and the inability to conduct detailed surveys of hydrate reservoirs, it is necessary to conduct logging drilling and sampling at a certain point based on expert judgment to realize hydrate reservoirs in the area. Definition of distribution

[0005] However, after the logging drilling and sampling work is completed, due to the unavoidable disturbance of the soil during the drilling process, the interaction between the seawater and the soil caused by the leftover drilling holes, and the reduction of the ballast protection effect of the overlying soil layer, it will directly lead to excessive porosity. Water pressure, temperature, salinity, PH, etc. change greatly, and the temperature field and pressure field of the reservoir have a great influence on the occurrence and distribution of gas hydrate, which will directly lead to the secondary formation of gas hydrate. distribution, which in turn affects the accurate assessment of the vertical content distribution of seafloor hydrate

In summary, the existing technology cannot accurately evaluate the secondary distribution of gas hydrates caused by drilling

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