Underwater production system and underwater production method of fluidized mining based natural gas hydrate

Abstract

The invention discloses an underwater production system and an underwater production method of fluidized mining based natural gas hydrate. The underwater production system comprises an underwater central collecting system, a slurry crushing and decomposing system, an underwater separating system, a transmission subsystem and a umbilical system. Compared with the prior art, the fluidized mining based natural gas hydrate underwater production system has the following benefits: according to the reservoir forming and mining characteristic of natural gas hydrate in, and by combining with the actualproblem of slurry lifting, the invention discloses a natural gas hydrate fluidized mining based underwater collecting, discomposing and sub-transporting production system. On one hand, the system reduces the slurry lifting risk in large height difference by a treatment facility from underground to the sea and improves the natural gas collecting efficiency; on the other hand, the system is adaptedto centralized collecting and treatment after underground multipoint dispersing production; and in addition, circulating suspension liquid is utilized to carry out suspension lifting on residual mudand sand after underground decomposition for further treatment on the sea to realize all-dielectric sealing collection.

Description

Technical field [0001] The invention relates to a natural gas hydrate underwater production system and method based on fluidized mining. Background technique [0002] Natural gas hydrate (hereinafter referred to as hydrate) is an ice-like crystalline compound with a cage structure formed by the contact of water molecules and small gas molecules (mainly hydrocarbon gases) under low temperature and high pressure conditions. The currently recognized reserves are extremely Abundant, its distribution is dominated by deep-water marine storage. Natural gas hydrate can be regarded as a highly compressed natural gas resource, 1m 3 Natural gas hydrate can decompose and release 160~180m 3 (Standard state) natural gas, based on this rough estimate, the total volume of natural gas contained in the global natural gas hydrate deposits is approximately 1.8×10 16 ~2.1×10 16 m 3 , Which is equivalent to twice the total carbon content of conventional fossil fuels in the world. Therefore, the energy...

AI Technical Summary

Problems solved by technology

However, although the above-mentioned technology has solved some technical problems in the fluidized exploitation of natural gas hydrate to a certain extent, and promoted the progress of this technology, there are still some parts that can be further innovated and optimized: (1) the fluidized exploitation method suitable for Natural gas hydrates are mainly located in sea areas above 1000m. For slurry lifting, the advantage of lifting efficiency is not obvious. In addition, during the lifting process, it is necessary to solve the problem of gas in the pipeline caused by changes in the ambient temperature and self-pressure of natural gas. (2) Although the method of underwater mud-sand separation has been proposed to improve the lifting efficiency, there are still flow guarantee problems described in (1). (3) For the mud and sand carried by natural gas hydrate mining, under the premise that the marine environment is sensitive, the mud and sand collection and treatment can be further optimized

Images