Single-well depressurizing mining system and method for marine gas hydrate

Abstract

The invention relates to a single-well depressurizing trial mining system and a single-well depressurizing mining method for marine gas hydrates. The method comprises the following steps: a comprehensive monitoring well drilling stage, a production well shallow part drilling stage, a decomposition monitoring well drilling stage, a core boring and sampling stage, an environment monitoring device installing stage, a production well deep part drilling and mining stage, a well sealing and equipment recovering stage. The system is provided with a production well, a comprehensive monitoring well, decomposition monitoring wells and an environment monitoring device, so that comprehensive mining data can be acquired and the mining safety of the marine gas hydrates can be guaranteed. According to the method, the mining of the whole mining process of the production well is monitored by adopting the two monitoring wells, the stratum temperature change, the hydrate in-layer flow data and the like in a mining process can be acquired, and the safe operation of a gas hydrate trial mining well can be guaranteed. The production well involved the method disclosed by the invention is drilled and cemented in stages, the blowout caused by sudden rise of the hydrate well pressure can be prevented, and the safety of the production well can be guaranteed.

Description

technical field [0001] The invention relates to a method for exploiting seabed oil and gas resources, in particular to a system and method for depressurizing a single well of marine natural gas hydrate, and belongs to the technical field of exploiting marine oil and gas reservoir resources. Background technique [0002] Natural gas hydrate is widely distributed in the sedimentary layers of the oceanic continental shelf. It is a kind of clean energy with huge reserves. It is expected to become the main energy source to replace oil and coal in the 21st century. At present, the most promising offshore natural gas hydrate exploitation method is the depressurization method, that is, the formation pressure is reduced by drilling, the natural gas hydrate is decomposed, and the decomposed gas and water rise to the water surface production platform along the wellbore under the extraction of the pump, thereby realizing Continued production of natural gas. The depressurization method ...

AI Technical Summary

Problems solved by technology

However, the exploitation of gas hydrate is different from conventional offshore oil and gas exploitation, and there are no examples of drilling wells for offshore gas hydrate exploitation, and there is no clear plan on how to deploy wells for offshore gas hydrate exploitation.

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