Materials that are not prone to polymerization are safe to use downhole. Sodium silicates are reactive and prone to polymerization — this is exactly what makes them useful in many other commercial applications. This tendency makes them dangerous to use downhole. These materials are an excellent choice for plugging and sealing pores in sandstone, and carbonate lithologies — not for removing more oil and gas from your well. Some major oilfield companies have patented the use of sodium silicate/waterglass type chemistry for stopping, reducing, or modifying pathways for fluid flow.