PQ silicates are water-based inorganic solutions of silica. The silica is in soluble polymeric form and can add value to a drilling mud formulation by causing changes in density, ionic strength, charge, etc. that are needed for critical drilling mud functions such as: drill-bit cooling, bit cleaning, effective cuttings removal to surface, downhole pressure control, and shale stabilization. Likewise, the use of silicate muds offers the advantages of prevention of bit-balling, differential sticking, and loss circulation in addition to the well-known use as a corrosion inhibitor.
Silicates are well-known as shale stabilizers providing coating and chemistry to prevent swelling and collapse in water. PQ silicates are non-toxic and one of the few field chemicals that can be beneficial to the environment, e.g., PQ's potassium silicate is used as well in agricultural applications as a fertilizer.
For conformance control of unwanted water and in cementing, the gelation and precipitation chemistries of silicates are exploited to give a cost- effective, durable, and high strength gel. By controlling the type and concentration of setting agent, sodium silicate can be made to gel and set in minutes to hours. Depending on depth of placement and desired reaction time the sodium silicate solution is formulated with an external or internal catalyst.
The process of drilling and producing a well generates large volumes of solids and liquids that require treatment prior to re-use or disposal. PQ sodium silicate, zeolite, and epsom salt can each be used to remove metals from produced water or frac fluids. Product selection is based on the type of metal and pH of the water. Sodium silicate can also be used to bind or encapsulate both organic and inorganic wastes from the oilfield.