The viscoelastic-surfactant micelle structures on the water-wetting behaviors of bituminous coal with nuclear magnetic resonance and molecular dynamic simulation.

This article investigates the effect of micelle structures formed by the viscoelastic surfactant cetyltrimethylammonium chloride (CTAC) on the wettability of bituminous coal, combining experimental techniques and molecular dynamics (MD) simulations. Experimental results show that CTAC solutions significantly enhance coal wettability by promoting water migration into smaller coal pores and reducing the contact angle on coal surfaces, without substantially altering the content of hydrophilic functional groups. MD simulations reveal that CTAC molecules adsorb on coal surfaces and form micelle structures that increase electrostatic interactions between water and coal, facilitating stable water adsorption; however, larger micelle clusters can hinder water diffusion and reduce wettability improvement. These findings provide insights into optimizing clean fracturing fluids for enhanced coalbed methane extraction.