Research On Upgrading Pipeline System And Relay Cabin Based On Natural Gas Hydrate Hydraulic Lifting Method

With the decline in oil production, people focus on other alternative fossil fuels in industry. Gas hydrates are widely distributed in earth, large numbers of gas hydrates stored in permafrost, deep sea and continental shelf areas. As an efficient, sufficient and clean alternative the carbon content of gas hydrates is more abundant than other carbohydrates under the same conditions. The geographical distribution and instability of Gas hydrates makes it difficult to be mined. So the industrial research of natural gas hydrate for exploration becomes necessary.The mining methods of gas hydrate are varied such as depressurization method, heating method, replacement method, and hydraulic lifting method. Hydraulic lifting method has the advantages of large amount output, stable mining, and simple operation prefer to other mining method which makes it an effective method.This paper introduces the properties of natural gas hydrates, sum up and compare several mining methods of natural gas hydrates and study the minimum convey speed of gas hydrate particles of gas hydrate hydraulic lift system based on the minimum convey speed of particles theory. Mathematical model of pipeline transportation system of hydrate hydraulic lifting is established and obtain the relationship of the flow rate, pressure, density and height of pipeline transportation system of hydrate hydraulic lifting. Study the influences of the particle concentration, particle diameter, convey speed of hydraulic lifting system on pressure drop.The simulation software CFD is used to simulate the flow field inside the buffer which is the important equipment of hydrate hydraulic lift system in a same operation condition and volume but different structures. Investigate the Particle deposition, the internal velocity distribution and the volume fraction of coarse particles, fine particles, seawater in the buffer.Simulate the flow field inside the cylindrical buffer in the different operating conditions such as changing the flow rate, hydrate particle size, slurry concentration, particle density. Investigate the velocity flow field, particle deposition, different volume fraction distribution of the flow field inside the buffer.