Abstract: A method is provided for reducing the concentration of radioactive materials or other trace contaminants in fluids withdrawn from subterranean reservoirs and also fluids in reservoirs. The method involves deposition of sorbent solids including, but not limited to, fine ion exchange resins, within the reservoir matrix surrounding a production well to act as an in-situ filter for dissolved radionuclides or other contaminants present in reservoir pore waters. For this purpose, the sorbent solid is either a) precipitated within the reservoir matrix by the reaction of ions or molecules of two or more carrier solutions or b) directly introduced into the reservoir as a solid component of a solid-liquid slurry using high-pressure injection techniques.

Abstract: A method is provided for reducing the radioactive material content of fluids withdrawn from subterranean reservoirs. The method involves deposition of sorbent solids within the reservoir matrix surrounding a production well to act as an in-situ filter for dissolved radionuclides present in reservoir pore waters. For this purpose, the sorbent solid is either a) precipitated within the reservoir matrix by the reaction of two or more carrier solutions or b) directly introduced into the reservoir as a solid component of a solid-liquid slurry using high-pressure injection techniques. Thereafter, fluids produced by the well contain significantly lower concentrations of radionuclides (e.g., principally radium and uranium ions), as radionuclides are removed from the inflowing reservoir fluids by means of ion exchange, adsorption, chelation, chemisorption, or coprecipitation with the in-situ filter medium.