Use of alkali metal silicates during formulation of drilling fluids

摘要

The presence of unmitigated metal ions in a drilling fluid can prevent acceptable rheological and fluid loss control performance from being realized during a drilling operation. Softening of a hard water source containing alkaline earth metal ions may allow the resultant treated water source to be used in formulating a drilling fluid with acceptable properties. Not all softening agents perform equivalently in this regard, and some softening agents may not be readily available. Methods for formulating a drilling fluid may comprise: providing a hard water source comprising one or more metal ions; introducing an alkali metal silicate into the hard water source to form a treated water source; and after forming the treated water source, adding a viscosifying agent to the treated water source to form a drilling fluid. The methods may further comprise drilling a borehole with the drilling fluid.