THERMASAL®

A high temperature stabilizer for polymer suspensions

DESCRIPTION

Thermasal is a two component thermal extender for most polymer based drilling, completion and workover fluids. Two primary mechanisms for polymer degradation (exemplified by rapid decrease in fluid viscosity) are: 1. Oxidation reduction reactions resulting in free radical formation, and 2. Acid hydrolysis. Thermasal is designed to prevent these reactions with a synergistic blend of a reducing agent to retard the formation, at elevated temperatures, of free radicals and an alkaline earth oxide to buffer pH.

The two components of Thermasal are:

  • Thermasal-A- an anhydrous salt antioxidant. (Packaged in 50 lb cans)
  • Thermasal-B- a fine grind magnesia compound. (Packaged in 50 lb or 25 kg sacks)

Thermasal may be used in brines such as sodium chloride, potassium chloride, sodium bromide, sodium formate, potassium formate, and cesium formate.

APPLICATIONS
Thermasal provides stabilized rheological and filtration properties at temperatures above 250°F for polymer suspensions which are formulated with sized, bridging and/or weighting solids. The addition of Thermasal to brine systems containing sized calcium carbonate or sodium chloride particles extends the thermal limit to 300°F and 325°F, respectively.

VISCOSITY COMPARISON OF CALCIUM CARBONATE FORMULATIONS MIXED IN VARIOUS BRINES UTILIZING
10.0 lb/gal NaCl (bbl) 0.96 -- --
9.0 lb/gal NaCl (bbl) -- 0.96 --
3% KCl (bbl) -- -- 0.96
Xanthan Biopolymer (lb/bbl) 1.25 1.25 1.25
FL-7 Plus® (lb/bbl) 3.75 3.75 3.75
Polytex AHT (lb/bbl) 4.2 4.2 4.2
Thermasal-A (lb/bbl) 2 2 2
Thermasal-B (lb/bbl) 3 3 3
Ultra Carb 12 (lb/bbl) 35 35 35
Properties, Initial and 16 Hours Static Age at 300°F Initial Aged* Initial Aged* Initial Aged*
Plastic Viscosity, (cP) 38 35 25 24 23 20
Yield Point (lb/100 ft 2) 47 41 46 40 38 30
Gel Strength (lb/100 ft 2) 13/18 16/20 12/17 12/13 11/15 8/9
LSRV (cP) 0.0636 sec -1 39,000 49,200 32,300 26,800 29,900 11,700

VISCOSITY STABILIZATION OF A SIZED SODIUM CHLORIDE PARTICLE FORMULATION UTILIZING Thermasal
10.0 lb/gal NaCl (bbl) 0.91 0.91
Xanthan Biopolymer (lb/bbl) 1.25 1.25
FL-7 Plus (lb/bbl) 3.75 3.75
Polytex AHT (lb/bbl) 4.2 4.2
ThermasalA (lb/bbl) -- 2.5
Thermasal-B (lb/bbl) 3 3
Ultrasal®  20 (lb/bbl) 66 66
Properties, Initial and 16 Hours Hot Rolled at 300°F Initial Hot Roll* Initial Hot Roll*
Plastic Viscosity (cP) 48 18 50 43
Yield Point (lb/100 ft 2) 68 11 65 46
Gel Strength (lb/100 ft 2) 16/21 1/1 16/21 16/19
LSRV (cP) 0.0636 sec -1 48,500 2,200 48,500 34,300
* Viscosities were recorded at ambient temperature after aging.