Fracture Flow Properties
& Critical Shear Analysis

As well as identifying the subset of open fractures in a fracture network, a key step in the FRC workflow is to identify those which are also dynamically active (a small proportion in fractured reservoirs).  To do this we use data such as shows, mud losses, production logs and well tests, calibrating with the core and image logs to identify specific flowing features or flowing intervals.

The geological record tells us that in situ stress, fractures and fluid flow are intimately associated. Likewise, in a reservoir under development in situ stress may act to dilate fracture aperture for particular orientations (a process known as ‘critical shear’). 

Together with our Geomechanics team we test for this process by integration of stress, fracture and flow data in the wellbore:

• Determination of the two principal horizontal stress axis orientations
  (σHmax and σHmin) from image logs and calipers
• Determination of their magnitudes from formation breakdown tests and modelling

Identifying preferred open fracture orientations is usually a key part of development strategies in fractured reservoirs.