Hydrate Formation And Injection Of Alcohol Antifreeze Law Technologu

Natural gas hydrate, with the snow appearance, is a complex compound formed from natural gas and liquid water under a certain temperature and pressure during the process of extraction, processing and transportation. These processes are remarkably harmed by the well bore plugging, pipe line blockage, valve restricted and facility jam, which caused by the gas hydrate existence.Shengshen gas field is the main block of Da Qing gas production incorporation. Gas hydrate blockage has often occurred in the transportation line because of the seasonal variation and affected the regular production, sometimes even stop production. In consequence, it is essential to perform the study of gas hydrate formation rule and the research of antifreezing by alcohol injection according to the condition of block in question.For the gas hydrate characteristics, experiment equipment (which includes: atomization visible high pressure reaction kettle, cooling water supply system, heating system, temperature control system, liquor and feeding system gas feeding system, etc.)has been developed. Several works has been finished through laboratory experiment and presented as follows: the study of hydrate formation condition in test hole, include the critical temperature of gas hydrate formation under different pressure and different gas compound; the influence of pressure and temperature on the hydrate formation; the affection of methanol inhibitor to the hydrate formation and decomposition; the rule of hydrate formation with time research; the variation characteristics and rule of hydrate decomposition with time.Through the experiment, the formation pressure and temperature of hydrate in Shengshen block has been made clear; the inbibitional effect of methanol injection rate on the hydrate formation has been quantitative analyzed; the rational preventive measure and the recovery processing project of methanol sewage has been put forward. Field test has been conducted to the three wells with the most serious condition in the block, which decreased the hydrate formation amount and lowered the influence of hydrate on gas production. The research results have important directive to Shengshen block, and also have a certain practical significant to natural gas industry.