Abstract: Chemical treatment agents are supplied to a well or borehole extending through an earth formation by subjecting the well to a fracturing treatment with a high pressure fluid and proppant particles. The proppant particles are thereby trapped in fractures in the earth formation. Some or all of the proppant particles are of porous insoluble inorganic material, and are impregnated with a chemical treatment agent, such as a scale inhibitor or a corrosion inhibitor. The porous particles may be of a ceramic or oxide material, for example a silica and/or an alumina-based material.

Abstract: Corrosion, scale-formation, or other deleterious processes are inhibited in an oil well by installing within the oil well (10) fluid-permeable elements, such as tubular filters (20), which comprises a suppressing material. Each filter (20) comprises two tubular filter screens (24) between which is a bed (26) of particles comprising suitable inhibitor material. The particles might for example be porous ceramic spheres impregnated with the inhibitor material. The inhibitor material gradually dissolves in the well fluids during operation, and may for example inhibit corrosion and/or scale formation.