Oil well cementing is the process of mixing and displacing a slurry down the casing and up the annulus, behind the casing, where is allowed to “set”, thus bonding the casing to the formation.
The main ingredient in most cements is “Portland” cement, a mixture of limestone and clay.
Primary Cementing
1- Remove drill pipe and bit.
2- Run steel casing (Has Float shoe) to bottom.
3- Run Mud Circulating to remove any cuttings (Conditioning).
4- pumping the Spacer/Flush into the casing to remove the mud from the well.
Prepare cement slurry(Mix water + dry cement + additives.
5- Drop wiper plug, to remove any remaining mud in the casing.
6- Then two mixed slurries pumped into the casing.
7- Another wiper plug is dropped, with mud. To remove the cement slurry inside the casing.
Function of casing
Protecting producing formations
Providing support for the casing
Protecting the casing from corrosion
Sealing off troublesome zones
Protecting the borehole in the event of problems