Study On Micro-mechanism Of Reservoir Damage During Stimulation Of Low Permeability Sandstone Reservoir

Low permeability sandstone reservoir plays an important role in the development of global oil and gas resources and is the main object of oil and gas exploration and development.With the development of oil exploration and development technology,the proportion of proved low permeability reservoirs in oil reserves in China has been continuously improved.Low permeability sandstone reservoirs have become an important target for exploration and reserve increase.Compared with conventional sandstone reservoirs,the particularity of low permeability sandstone reservoirs determines that certain stimulation measures are generally needed in the process of reservoir development to achieve industrial productivity.Hydraulic fracturing is an effective method for low permeability sandstone reservoir stimulation,but the effect of fracturing stimulation is affected by many factors.Based on low permeability sandstone reservoir of xingouzui formation in jianghan oil region as the research object,the geological information,the construction measures and effect and reservoir microscopic geological features and indoor evaluation research methods,the combination of reservoir in the process of transforming into the well fluid are studied and the interaction between the reservoir rock,emphatically from the Angle of the micro reservoir sensitivity damage and studies the relationship between the characteristics of reservoir property.Research shows that: the target belongs to anhydrite cementation of low permeability sandstone reservoir and fracturing job lead to the reservoir,such as temperature,pressure and formation fluid salinity changes will change the formation of original water sensitivity minerals-precipitation conditions,the dissolution of anhydrite reservoir has obvious scale tendency,reservoir damage in water sensitivity,acid sensitivity damage and particle migration.The main cause of water sensitive damage is hydration expansion,dispersion/migration,dissolution and reprecipitation of anhydrite,and the secondary cause is hydration expansion and migration of a small amount of clay minerals in the reservoir.Through the above research,the corresponding protection countermeasures are put forward for the target reservoir,which provides powerful technical help for the exploration and development of Xigouzaizui reservoir.