UNIFLAC Fluid Loss and Gas Migration Control Additive for Cement | SLB


Universal fluid-loss additive

concrete texture
concrete texture

The UNIFLAC universal fluid-loss additive for cement product family contains universal and cost-effective solutions for fluid-loss and gas migration control for all cementing applications. Solid solutions for dry-blending in the cement include D167 and D167A. Liquid solutions for adding to the mix water include D168 and D168A. The additives are custom-made third-generation solid polymers that can be predissolved in the mix water or dry blended with the cement. The robust properties make slurry design very simple and produce predictable results in the field from the surface casing to the liners.

Temperature range:
50 to 500 degF [10 to 260 degC]
Slurry density range:
10 to 24 ppg [1,198 to 2,875 kg/m3]
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Required UNIFLAC additive concentration to achieve API fluid loss of 50 mL/30 min is easily predictable at different temperatures and slurry densities.


  • Dry-blend in cement using solid UNIFLAC additives D167 and D167A
  • Add to mix water using liquid UNIFLAC additives D168 and D168A
  • Add fluid-loss and gas migration control


  • Low cost per barrel of cement
  • Savings from less time spent waiting on cement


  • Low sensitivity to cement brands and temperature
  • Applicability in temperatures from 32 to 400 degF [0 to 204 degC]
  • Applicability in densities from 12 to 19.5 lbm/galUS [1.44 to 2.34 kg/L]
  • Low concentration requirements
  • Excellent slurry rheology
  • Compatibility with Schlumberger retarders
  • Simplified slurry design
  • Simplified logistics—few additives required
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UNIFLAC additive has low sensitivity to various cement brands. The concentration required to achieve a fluid-loss value of 50 mL/30 min remained consistent with different cement brands.

Low sensitivity and synergy

Test results show the very low sensitivity of UNIFLAC additives to small temperature or concentration variations. They are least sensitive to cement brands at bottomhole circulating temperatures (BHCTs) from 32 to 400 degF [0 to 204 degC]. Synergy between Schlumberger retarders and UNIFLAC additives, such as UNISET additive, provides additional operational benefits. Early compressive strength (CS) development reduces waiting-on-cement time. The concentration of retarder required to achieve a desired thickening time is reduced.

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UNIFLAC additive has minimal retarding effect at low bottomhole temperatures. These 15.8-Ibm/galUS [1,893 kg/m3] slurries were tested at 70 degF [21 degC].
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A lower D161 retarder concentration is required to achieve a desired thickening time with UNIFLAC additive for a similar fluid-loss value of 50 mL/30 min. These Class H slurries were tested at 350 degF [177 degC].