Cement Placing Procedure
1. Clean the hole of as much broken material as possible.
2. If cement is to be spotted above the bottom of the hole, place a plug or backfill to the desired level with fine sand.
3. If the cement is to be placed through pipe or rods, run them "upen ended" to the bottom of the hole. Circulate fluid in the hole to ensure that it is clean. Lift the rods about 200 mm(8 in) above bottom.
Prepare the dump bailer or other equipment if other methods of placing are to be used.
4. Work out the quantity of cement required. (Use fondue or setting additives to give quicker set). Mix cement thoroughly and keep mixing until it is poured down the tremie or otherwise run into the hole.
5. Place down the hole.
Note: Fill a small container (e.g. a drink can) with a sample of the slurry to monitor setting time.
Tremie method: Pour evenly using a funnel. Shake the tremie tube to keep cement moving. Raise the tube as the hole fills. When all cement has been poured, raise the tremie tube clear of the cement in the hole and mur water through the tube. Pull the rods and the them.
Bailer method: Fill the bailer with the cement Run to the bottom to lift the valve. Lift slowly as bailer empties,
Cement sausage method: Make up the sausage and lower into the hale on the sand line. Run the drilling tools in to break the bags. Pull the tools and the empty bag.
6. Check the cement level. When the cement sample shows the cement to be firm, run the drill string into the hole to check the level of the top of the cement. If the cement is too high up the hole, it can be "washed out" to the correct level.
7. Drill the cemented hole only when the sample shows that the cement has fully hardened.