Hutubi Gas Storage Optimization And Application Completion Fluids

There is a big imbalance between supply and demand of natural gas. Combined with the rapid development of the downstream industry of natural gas in recent years, this further exacerbate the contradiction between supply and demand, all those resulting in the very difference of gas use between summer and winter. Generally speaking, gas use in summer is low peak while winter is peak. So we use nature gas storage as the bridge between gas applications and supply to solve the relationship between gas supply and demand imbalance and variability.Hutubi gas storage is a depleted oil and gas reservoir storage. The characteristics of this gas storage is using depleted oil and gas reservoir to convert gas storage. After decades of development process, oil and gas reservoir pressure coefficient is very low, in the process of building gas storage is apt to cause more corresponding engineering accident. Translated according to the Hutubi pressure coefficient, even with a density of1.Og/cm3drilling fluids in the process of drilling and completion, will cause up to19MPa positive differential pressure in Ziniquanzi reservoir. Therefore, in order to guarantee gas injection ability and exploitation ability of the gas storage well, we must strengthen reservoir protection of Ziniquanzi formation in the process of drilling and completion. At the same time according to Sensitivity analysis based on the Ziniquanzi group, the reservoirs have strong water sensitivity and salt sensitivity. Under this positive pressure difference, leakage of the working fluid may occur in the working process, the working fluid leakage which is composed with solid phase and liquid phase will cause damage to the reservoir, finally lower reservoir injection ability and exploitation ability. So in the process of drilling and completion, we have to prevent leakage of working fluid to minimize the formation damage, and ensure the gas storage well injection and production capacity.In this paper, through a large number of literature and combined with the geological characteristics of Hutubi area, analyzing the mechanism of reservoir damage in gas well completion process from many different angles. Through analysis and study on the geological data of Hutubi area:Ziniquanzi group reservoir belongs to medium porosity, reservoir lithology is mainly fine sandstone and siltstone, clay mineral is mainly composed of the illite/smectite interstratified mineral, and is a kind of strong water sensitivity, salt sensitivity formation.Get a new completion fluid system formula through many tests, and evaluation of Hutubi area reservoir characteristics of the corresponding work. Independent research and development of high temperature and high pressure dynamic reservoir damage evaluation instrument. The experimental results show that, the new system fluid and completion can form a temporary blocking to protect the reservoir from the working fluid against.According to the characteristics of Hutubi reservoir, completed the process of fluid mixing and injection circulation, and successfully applied to the field.The results of on-site construction showed that:the new completion fluid has a high bearing capacity, at the same time very easy to achieve discharge. Operating wells obtain a higher capacity after using coiled tubing induced flow.