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Chart of sample weight against time, showing weight stabilising as cleaning completes
Fluids extracted during CO2 cleaning, shown under visible and ultraviolet light

Special Core Analysis

Huff & Puff CO2 Cleaning for Tight Rocks

Cleaning intact low and ultra-low permeability plugs with pressurised CO2, removing mobile fluids without the fabric damage that crushing or solvent extraction causes.

What you receive

  • Cleaned intact plugs ready for measurement
  • Removal of hydrocarbons, water and mud invasion
  • No rock fabric damage from crushing
  • Typically complete within two weeks
  • Process verified by weight stabilisation

Sample dimensions: 0.5″ length × 1″ diameter.

  • Core has to be cleaned before porosity, permeability and saturations can be measured, and the objective is to remove all hydrocarbons, water and any drilling mud that invaded during coring.
  • Cleaning tight rock in distillation-extraction equipment is slow, and both the process and the solvents damage the rock.
  • Crushing tight rock before extraction is common practice for reducing cost and time, but it destroys the fabric the measurement is meant to characterise.
  • Our method uses pressurised CO2 above room temperature to reach supercritical conditions, then removes mobile fluids by automated gradual pressure release.
  • The process ends when sample weight stabilises.
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