▎ 摘　　要

NOVELTY - Preparing a polymer-sand nanocomposite lost circulation material involves applying a surface modification comprising attachment of an organic cross-linker to the surface of sand particles by preparing a cross-linker solution comprising one or more organic cross-linkers; combining the cross-linker solution and the sand particles to generate a cross-linker modified sand precursor; and heating the cross-linker modified sand precursor to a temperature of 120-180 °C for at least 2 hours to generate a cross-linker modified sand; preparing a polymer hydrogel by combining a hydrogel polymer, additional organic cross-linker, and a salt; and combining the polymer hydrogel and the cross-linker modified sand to form the polymer-sand nanocomposite. USE - Method for preparing polymer-sand nanocomposite lost circulation material for forming barrier to overcome lost circulation in hydrocarbon wellbore. ADVANTAGE - The lost circulation materials possess chemical, mechanical and thermal stability, and provides low cost agent to reduce the cost per volume in filling or blocking a lost circulation zone.