LOW PERMEABILITY ROCKS ARE LESS SENSITIVE TO STRESS

The stress sensitivity of reservoir rocks is related to their tightness. Because rocks of low permeability are tighter than those of high permeability, they should be less stress-sensitive than those of high permeability. However the stress-sensitivity curve measured in laboratory showed the reversal, i.e. the rocks of low permeability are more stress-sensitive than those of high permeability. Research of this paper found that the curves of lab oratory were affected by the systematical error of measurements. The property of rock itself is concealed in the measurement. The micro-interstices between core and sleeve play a role in core measurements.