Acid/sandstone reaction modeling for sandstone-matrix acidizing
Abstract：Mathematical models for acid injection and shut-in reaction periods were established during acidization of sandstone-matrix by considering the effect of temperature on reaction rate. The models were solved by numerical method, and the reaction between acid and sandstone was studied. The results can predict the effect of the acid/sandstone reaction. The calculation re- sults show that the concentration of HF decreased quickly during the acidization of sandstone- matrix in radical direction with HF operating range of less than 0.4 m. The dissolving capacity of the secondary H2 SiF6 was equal to HF, which is a beneficial complement for HF. Rapid re- action mineral in the range of 0.4 to 0.9 m is mainly dissolved by Hz SiF6. It increases acidizing penetration depth. The deposition of Si（OH）4 increases with time, but a flowback of the reac- ted acid is needed after the reaction for some time, otherwise secondary precipitation will oc- cur, which affects the acidization of sandstone-matrix. The rate of HF consumption increases with the formation temperature, which reduces the operating range of HF. The concentration
Keywords：sandstonematrix acidizingacid/sandstone reactionmathematical modelsimula-tion
Publication Date：2012-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 236-241 )