Research On The Conditions Under Which West-east-Transferred Gas Hydrate Forms

Hydrate of methune is a sort of solid crystals like ice. It is formed under certain temperature and pressure. Some water molecules linked together by hitrogen bonds to form a net structure, When this structure contains some low molecular gas molecules, hydrate is created. In some oilfields in China, especially under such conditions as long gas pipelines in desert oilfields under such conditions as in the gas-gathering network and shoal oilfields, The hydrate is likely to forms. For example, an incident which is caused by hydrate clogging, had led to the break down in Jinzhou 20-2 subsea pipelines that transfer gas condensate in China National Offshore Oil Corporation. Therefore, problems of this aspect should be fully taken into consideration when planning pipelines. The research focus on whether or not natural gas hydrates may form in the pipeline of "The Gas from Rich Western Region to the East" in order to take corresponding preventive measures. In this paper we have researched and established the simulation test method for the formation conditions of natural gas hydrates; provided the formation conditions of natural gas hydrates in gas fields including Kela 2, Yingmai 7, Yangtake, Jilake etc.; taken natural gas samples from each gas field of "Gas Transmission from West to East" or acquired natural gas composition data; having provided the formation conditions of natural gas hydrates through combining simulation test with software prediction method. The outcomes of the research have provided technical support for both planning design of "The Gas Transmission from West to East" project and the early-stage work of Russian Gas Transmission project.