Abstract: The method and apparatus of the invention involves treatment of a subterranean site, i.e., the producing sand sites, in a well bore to prevent infiltration of subterranean solids into the well bore or to stabilize or modify the area surrounding a portion of the well bore. Said invention includes the local injection of a selective substantially occluding quantity of a curable resin foaming material from a source located at the subterranean site. Said material, upon curing, forms a substantially chemically and dimensionally stable porous resin mechanically rigid occluding structure which is permeable to liquids and gases while same is impermeable to solids. After injection, the foaming material will cure in situ to form the above-mentioned structure at the subterranean site.