API Classification for Oil Well Cements Flashcards
Class A Cement
0-6000 ft. When Special properties are not required. Water-CEment ratio .47
Class B
0-6000 Ft. When conditions require moderate to hight sulfate resistance.
Class C
0-6000 ft. When conditions require early strength. High C3S content Water -CEment Ratio - .56
Class D
6000-10,000 Ft. Used with moderately high temperatures and pressures
Class E
10,000-14,000 ft. For High Temps and high pressures
Class F
10,000-16,000 Ft. Extremely high Temps and PRessures
Class G and H
BAsic Well cement 0-8000 ft. OR can be used with accellerators and retarders to cover a wide range of well depths and temps. No additions other than calcium Sulfate and/or Water shall be blended with the clinker during manufacture
Manufacture
Made of Limestone or other materials high in calcium carbonate content, Clay or Shale. Some iron and aluminum oxide if they are not present in sufficient quantity in the clay or shale.. The raw mixture is heated to 2600 F. The heat causes chemical reaction between material and clinker. The clinker is ground with a controlled amount of gypsum to form PORTLAND CEMENT.
What are the purposes of Oilfield Cement
- To isolate fluid zones and maximize stability
- To mount the BOP
- Ensure optimum reservouir protection
Finer than Portland Cement
Class C Cement. High C3S levels (TriCalcium Silicate) Provides better strength up to 30 hours of curing time. More expensive and wont be used unless its special properties will be needed. Portland Cement with Calcium Chloride will give better strenght without accellerators.
Class G and H Cement are similar to what?
Class B Cement - Ground finer so it is more consistant. Does not come blended with any accellerators, retarders or viscocity control agents exept gypsum which is blended with the clinker. Can meet a wide range of temerature controlled by addatives.
D,E,F Cement
Will not be used unless their special properties are needed because of cost.
Most common retarder
Calcium Lignosulfonates - Similar to HR5
