Application method of accurate evaluation device for vertical content distribution of seabed hydrate reservoir

Abstract

The invention relates to content determination of seabed hydrates, in particular to a using method of a seabed hydrate reservoir vertical content distribution accurate evaluation device, which comprises the following steps: assembling the whole device into a whole and screwing the whole device into a seabed drilling well; exciting the natural gas hydrate to generate gaseous substances; a directional guide channel corresponding to the thermal excitation system in the working state in S2 is opened, so that the gaseous natural gas hydrate generated in the layer enters the screw-in type long sleeve through the directional guide channel; the gas collection system collects gaseous natural gas hydrate. Components and content in the box body are analyzed and recorded through an optical ranging unit and a resistivity unit. Repeating the actions of S4 and S5 until one collection period is finished; and processing and analyzing data. According to the method, accurate evaluation on the vertical content distribution of the seabed hydrate is realized.

Description

technical field [0001] The invention relates to the content measurement of seabed hydrate, in particular to a method for using a device for accurately evaluating the vertical content distribution of seabed hydrate reservoirs. Background technique [0002] Knowing the location and distribution characteristics of gas hydrates is very important, and it is also the first prerequisite for 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 joint detection technologies. The most important effective detection method at this stage is to use the detection of the distribution of cold seep plumes in seawater to further complete the determination of the distribution area of ​​hydrates and the development of hydrates. [0003] Theory and practice have proved that the temperature and pressure conditions for the formation of hydrates exist...

AI Technical Summary

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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