Experimental study on gelling property and plugging effect of inorganic gel system (OMGL)

By means of instrumental test and theoretical analysis, the gelling degree, extreme gelation concentration and plugging performance of inorganic gel (OMGL) have been studied and its appearance on surface of rock skeleton has been observed. Results show that inorganic gel is formed by reaction between OMGL system and Ca2+. The higher the concentration of OMGL and Ca2+, the higher the gelling degree. When the concentration of OMGL system is 2 to 3 times that of Ca2+, the inorganic gelling degree is the most suitable, and not sensitive to temperature. Under the same core permeability, residual resistance factor increases with the increase of concentration of OMGL system. When the concentration of OMGL system is the same, residual resistance factor decreases with the increase of core permeability. There exists a reasonable matching relation between core permeability and concentration ratio of OMGL system and Ca2+. Plugging effect of cores with the same permeability can be speculated from Ca2+ concentration. The inorganic gel coats on rock surface by absorption in the form of ionic bond of “-Si-O-Si-” instead of depositing in the channels.