Gas hydrate pressure-retaining sampler

Abstract

The invention relates to a gas hydrate pressure-retaining sampler at least comprising an external pipe assembly, a middle pipe assembly, an internal pipe assembly, a fishing part and a linkage mechanism. The external pipe assembly is arranged at the bottom part of a drill rod; the internal pipe assembly is positioned in the external pipe assembly; the middle pipe assembly is positioned between the external pipe assembly and the internal pipe assembly; the fishing part is positioned above the internal pipe assembly and the middle pipe assembly, and the bottom part of the fishing part is fixedly connected with the top parts of the internal pipe assembly and the middle pipe assembly. The internal pipe assembly of the gas hydrate pressure-retaining sampler is used for loading a rock core, the inner part of the middle pipe assembly forms a sealed cavity under the action of upper sealing and lower sealing when sampling is required, the pressure of the rock core sample positioned in the sealing cavity keeps unchanged, and finally the sampler except for the external pipe assembly is lifted to the ground surface through the fishing device; and with the sampler, decomposition of gas hydrate during sampling can be effectively avoided.

Description

technical field [0001] The invention belongs to the field of drilling, and in particular relates to a gas hydrate pressure-holding sampler, which is mainly used for pressure-holding sampling in the process of natural gas hydrate exploration and development, and can also be used for pressure-holding sampling in the exploration of other energy sources. Background technique [0002] Natural gas hydrate is a solid substance produced when water and natural gas are mixed under high pressure and low temperature conditions. It is a new type of high-efficiency energy source. Its composition is similar to that of natural gas that people usually use, but it is purer and easier to use. , high combustion value, clean and pollution-free. So far, at least more than 30 countries and regions in the world are conducting research, investigation and exploration of gas hydrates. As an important new energy mineral deposit in the future, China included natural gas hydrate in the "Twelfth Five-Yea...

AI Technical Summary

Problems solved by technology

Therefore, in order to obtain natural gas hydrate rock samples, the rock samples must always be under a certain high pressure during the sampling process. Conventional samplers are generally not airtight and cannot maintain pressure.

At present, some samplers are equipped with low-temperature cooling devices in the structure to slow down the decomposition of natural gas hydrate by maintaining low temperature, but the implementation effect of these samplers is not ideal, because the state maintenance of natural gas hydrate is more dependent on the high-pressure environment, so It is an urgent problem to be solved in this field to provide a high-tightness pressure-holding sampler

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