Free Balanced Cement Plug Calculator at the end of this post. Check it out ! The most common placement method is the balanced plug technique. The work-string is run into the wellbore to the desired depth for the plug base. Contamination or mixing with the control fluid is avoided by the use of appropriate volumes […]
Max Out Your Cement Coverage
If we consider the main variables to ensure proper mud in hole replacement with cement: stand-off, fluids rheology (friction pressure hierarchy) and placement regime (as related to pumping rate); the amount of cement left in the hole (cement coverage), if no losses, quickly reduces (leading to increase cement returns, either to surface or above the […]
Cementing Flowchart
In recent weeks, I received some reader requests to include cement job processes or procedures as reference material on the website. I was initially puzzled about the best way to do that without going into too much detail. I went to work to think of whether a cementing flowchart would capture everything sufficiently. How can […]
Cementing. Challenges across permeable zones
This article will provide you with some actionable suggestions for cementing across permeable zones. In previous posts, I have already talked about the effect of formation permeability on the apparent cement presence behind casing, as seen on cement logs. (See: Excellent cement job, but with terrible results … how is this possible?) Keep in mind that […]
Forensic Cementing
Forensic is a term usually associated with crimes. Criminal forensics is the use of science to investigate a crime, but how is this applicable to Well Cementing? Actually, some well-cementing failures could easily be considered a crime, because of their effect on people, the environment, assets, and companies’ finances. The objective is to thoroughly “collect, […]
Cement Slurry design Basics
First, here is a handy table to simplify the process of cement slurry design: Additive Type Purpose Considerations Extenders IWater, Bentonite (clays), pozzolans, amorphous silica, Sodium Silicate, etc. Reduction of hydrostatic or greater economy.Lower slurry density from less than 15.8 down to 11.5 ppg, typically.Higher slurry yield (more slurry volume per sack). Change slurry rheology […]
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