Study of clay stabilization mechanism and adsorption behavior of organic ammonium salts with low molar weight

Abstract

Low-permeability sandstone reservoirs with low clay content are prone to water-sensitive damage during the fracturing process. In field applications, serious formation damage occurred with the conventional fracturing fluid system using KCl clay stabilizer. The introduction of SP clay stabilizer into the fracturing fluid formulation system significantly reduced the water-sensitive damage during fracturing and improved the reservoir transformation and production enhancement effect. In this paper, the clay stabilization mechanism of two substances, inorganic clay stabilizer KCl and organic ammonium salts with low molar weight SP, is studied by tests of swelling inhibition, ζ-potential test, and scanning electron microscope test to compare. On this basis, the adsorption behavior of SP on the surface of clay minerals is also studied in depth by isothermal adsorption and desorption experiments to explain mechanistically the difference of two different clay stabilizers on the fracturing effect, which helps to solve the formation damage problem in the fracturing and production enhancement process of low-permeability sandstone reservoirs with low clay content.