After complete the cement balanced plug job, you should need to go back in hole and attempt to tag to see where the actual TOC is.
You should be careful when you try to find the top of cement otherwise you may not have a big problem.
These procedures are good drilling practice which you can adapt for your operation.
1. First of all, you need to know where the calculated TOC is.
2. Trip in hole to approximately 1-2 stands above TOC.
3. Make up top drive or kelly depending on the rig set up.
4. Bring pump up to slow rate. This depends on how the BHA is set up. I cannot specific flow rate.
5. Slowly wash down and monitor the weight.
6. Wash down until you see solid weight tagged on a driller gauge.
What will be happened if you don’t wash down to tag the top of cement?
The BHA may be in the green cement (cement is not properly set up) and when the pump is turn on, the cement will flash set. Finally, the drill string will get stuck.
If you want to know about struck pipe in the cement, please read this article “Soft Cement Causes Stuck Pipe”