Research On Process Program Of Drainage Gas Recovery System Of Natural Gas Hydrate

Natural gas hydrate (short for NGH), also called “flammable ice”, contains plenty ofmethane or other hydrocarbon gas，and is flammable. The energy produced by the NGH isdozens of times higher than the conventional energy sources such as coal, oil and natural gasin the same condition. The NGH has the same application range with natural gas, and does notproduce any residue and waste gas after combustion, so it is considered as a substitute forpetroleum. NGH is very rich in the world, and many countries have conducted the experimentin exploiting NGH.Three kinds of methods are usually used in the NGH’s exploitation: thermal-stimulationmethod, depressurizing method, chemical inhibitors method. The water and gas produced byNGH rise to the ground together. In this paper, a new NGH’s drainage gas recovery methodbased on the existing exploitation techniques is proposed.In this method, an axial flow guidevane type gas-liquid cyclone separator is used downhole to separate the gas-liquid mixture,and electric submersible pump system is used to lift the separated water to the ground.The simulation test installation is reasonable design and built, the gas-liquid separationtest and the liquid level control test are conducted. The results show that the air inflowinfluences the separation performance seriously, the drain-pipe can influence the separator’sflow field, and the guide vane of25°has the better efficiency. The closed loop control systemused in the liquid level control system can steady the liquid level at the designated level.