Facies Definitions

Facies definitions naturally vary from field to field (and between different operators drilling in the same field). Thus, the examples below are provided to support our most abundant facies interpretation scheme that is applied by default in the Western Canadian Oilsands region.

Oilsands Common Lithology Cutoffs:

Massive sand
  • Sand is very clean, cutoff of <10%
  • VSH near zero
  • Indistinct bed boundaries and few laminations

Planar-tabular cross-bedded sand
  • Very clean sand, cutoff of <10%
  • >10 deg flow cross-beds, often alternating direction
  • Flat scour surfaces (<5 deg)

Trough cross-bedded sand
  • Very clean sand, cutoff of <10%
  • >10 deg cross-beds 
  • Incline scour surfaces 

Laminated sand
  • <10 deg beds, cutoff of <10%
  • No truncations or scour surfaces
  • Can be parallel to overlying IHS sequences

Sand with clasts
  • Any of the above sands
  • Matrix supported mud clasts
  • VSH cutoff of 20%

Sandy IHS
  • VSH cutoff between 10% and 40%
  • Inclined beds of alternating mud and sand with consistent dip direction and magnitude (lateral

Muddy IHS
  • VSH cutoff between 40% and 80%
  • Inclined beds of alternating mud and sand with consistent dip direction and magnitude (lateral
  • Image also used to confirm the percentage of mud

  • VSH cutoff of 80%
  • Boundary between Mudstone and IHS Mud occurs where neutron porosity is 15% higher than
     density porosity
  • Image, GR, PE secondary indicators
  • >90% mud
  • Usually highly bioturbated
  • Bedding almost always flat

Mud Breccia
  • VSH cutoff between 20% - 80%
  • Sandy matrix with angular mud clasts

(Siderite) Cemented Sand
  • Image generally very light-coloured
  • Usually a few cm's thick
  • May be discontinuous or nodular in appearance
  • Most commonly occur above McMurray
  • PE spikes
  • GR, neutron and density decrease

Silty Mud
  • Reserved for above the McMurray Formation
  • Equivalent to IHS Sand (40-80% VSH), but without the IHS bedding

Silty Sand
  • Reserved for above the McMurray Formation
  • Equivalent to IHS Sand (10-40% VSH), but without the IHS bedding

Interactive bioturbation interpretation with following designations:

  • Heavy bioturbation
  • Moderate bioturbation
  • No bioturbation

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