Abstract: A spacer fluid contains one or more hydratable polymeric viscosifying agents having a particle size distribution such that a minimum of 90% of the particulates are retained on a 20 mesh screen. The spacer fluid may further contain one or more surfactants, viscosity thinners, organic solvents, weighting materials, suspending agents and antifoaming agents. The spacer fluid may be used to position a first fluid into a wellbore annulus of a wellbore containing a second fluid. The spacer fluid may further be used to fluidly isolate at least a portion of a wellbore annulus in a wellbore containing an oil-based drilling mud and an aqueous cement slurry.

Abstract: A well cementing method includes combining a spacer polymer with a liquid in a first mixer and producing a spacer polymer blend yielding a spacer pumped into a well using a product pump. The method includes combining a cement additive with the liquid in the first mixer and producing a cement additive blend yielding a wellbore cement pumped into the well following the spacer using the product pump. Another well cementing method includes combining a cement additive with a liquid in a first mixer and producing a cement additive blend. The method combines bulk cement materials and the cement additive blend in a second mixer and produces a wellbore cement pumped into a well. A well cementing system includes a liquid pump, a first mixer, an additive feeder, a second mixer separate from the first mixer, a cement feeder, and a product pump.

Abstract: A well cementing method includes combining a spacer polymer with a liquid in a first mixer and producing a spacer polymer blend yielding a spacer pumped into a well using a product pump. The method includes combining a cement additive with the liquid in the first mixer and producing a cement additive blend yielding a wellbore cement pumped into the well following the spacer using the product pump. Another well cementing method includes combining a cement additive with a liquid in a first mixer and producing a cement additive blend. The method combines bulk cement materials and the cement additive blend in a second mixer and produces a wellbore cement pumped into a well. A well cementing system includes a liquid pump, a first mixer, an additive feeder, a second mixer separate from the first mixer, a cement feeder, and a product pump.

Abstract: A spacer fluid contains one or more hydratable polymeric viscosifying agents having a particle size distribution such that a minimum of 90% of the particulates are retained on a 20 mesh screen. The spacer fluid may further contain one or more surfactants, viscosity thinners, organic solvents, weighting materials, suspending agents and antifoaming agents. The spacer fluid may be used to position a first fluid into a wellbore annulus of a wellbore containing a second fluid. The spacer fluid may further be used to fluidly isolate at least a portion of a wellbore annulus in a wellbore containing an oil-based drilling mud and an aqueous cement slurry.