The optimal cement slurry mix design principle
There is a principle that I have always come to appreciate when talking about designing cement slurries. This principle is easy to remember: ‘the simpler, the better’. In this context, this means the use of the less possible additives, in their lowest effective concentration, that can provide the desired cement slurry features.
We base the principle on the assumption that there is a level of interaction* between all the components in a cement slurry. So, by reducing the number of elements and their concentration, the side effects would be minimized.
However, sometimes this is not that easy. The cement slurry mix design formulation would strongly depend on the experience of the laboratory itself (database) and the lab technician.
The flowchart below is a simple point of departure to design conventional cement slurry systems for each well-cementing laboratory.
Depending on workload, experience, availability of quality cement and chemicals, this cement slurry design flowchart is adapted to ensure that we can deploy reliable fluid systems.
(*) Interaction = the balance between desired (targeted) and negative (side effects) reactions.
What steps do you take to make corrections in the following cases?
Please share them in the comments section below
- Rheology too Low
- Gelation problems
- Compatibility Issues (with the mud)
- Static Gel Strength too Low (45 min)
- Compressive strength Development (too slow) or Max. value (too low)
BONUS: Visible Vortex @ 12000 rpm (blender) = Good surface mixability