In order to stabilize a downhole emplacement such as a bored or drilled hole forming a well, it typically requires multiple materials that are dry blended in a pneumatic bulk plant and then injected down hole in a cementing process. These dry materials can include cement, pozzolanic fly ash, silica, chemical additives that alter the cure time (accelerators/retarders), fluid loss materials, viscosifiers, defoamers, friction reducers, extenders, and other chemical additives that alter a product's performance downhole. These materials are blended in the pneumatic bulk plant and require multiple transfers to obtain a product that is sufficiently homogenous. Once the blending process is complete, the performance characteristics of the product are set since the blended mix cannot be re-mixed once it is removed from the bulk plant location.
The blended dry product is then transported to the site of the oil/gas well using bulk storage units (e.g. bulk trailers, or transports). The product is then introduced to a pumping and mixing truck, such as by pneumatic conveying. In the mixing truck, water is added to the dry product in specific measured quantities to achieve a desired density product slurry that can be measured using a densitometer. The mixing of water with the dry product is done “on the fly”—that is, continually mixed and pumped: pumping operations are not stopped during mixing operations in which the desired product slurry density may be achieved automatically through an electronic control system. The mixing truck may include controls such as water and cement throttling valves that are adjusted dynamically via the electronic control system to ensure that the measured density of the fluid is in agreement with a desired density that is typically determined by the user.
When the slurry mix has achieved the desired density, it can be pumped downhole within a well form casing that is pre-positioned in the well. A drilling or work over-rig may be used to pump the slurry mix in which an annular space between the wellbore and casing are filled incrementally as the slurry mix is pumped.