| GLC 1 | Cellophane flake; utilized with fluid loss additives to prevent loss of entire cement slurry to thief zones; optimum concentration is 0.125 to 0.25 lb./sk of cement. |
| GLC 2 | Graded ground coal, high melting point, utilized to prevent loss of entire cement slurry to thief zones; effective in all types of cement slurries at all temperatures; normal concentration is 12.5 to 25 lb./sk of cement. |
| GLC 3 | Ground gilsonite; utilized to prevent loss of entire cement slurry to thief zones and as an extender, with a melting point of 380°F (193°C), normal concentration is 5 to 20 lb./sk of cement. |
| GLC 4 | Ground rubber; prevents loss of entire cement slurry to thief zones. |
| GLC 5 | Carbo beads; sized carbon spheres utilized in all types of cement systems to prevent loss of entire cement slurry to thief zones. |
| GLC 6 | Treated cellulose fibers utilized to prevent loss of entire cement slurry to thief zones. |
Specialty Oil Field Additives