Skin factor is a numerical value used to analytically model the difference from the pressure drop predicted by Darcy's law due to skin. What is the typical range of this factor?

Skin factor is a numerical value used to analytically model the difference from the pressure drop predicted by Darcy's law due to skin. What is the typical range of this factor?

• A. -10 to 50
• B. -50 to 50
• C. -6 to 100
• D. -20 to 80

Answer: (C)

Skin factor represents the near-wellbore flow effects that alter the pressure drop from what Darcy’s law would predict. It is a dimensionless number that can be negative when stimulation or enhanced permeability reduces resistance, or positive when damage or blockage increases it. In field practice, this factor can span a wide range because near-wellbore conditions vary from mild stimulation to severe damage. The typical broad range is about -6 to 100, capturing both small improvements and substantial penalties. Negative values indicate some stimulation effects, while very large positive values reflect significant near-wellbore restriction. The other ranges don’t cover this full spectrum or tend to constrain the magnitude too much.

Skin factor represents the near-wellbore flow effects that alter the pressure drop from what Darcy’s law would predict. It is a dimensionless number that can be negative when stimulation or enhanced permeability reduces resistance, or positive when damage or blockage increases it. In field practice, this factor can span a wide range because near-wellbore conditions vary from mild stimulation to severe damage. The typical broad range is about -6 to 100, capturing both small improvements and substantial penalties. Negative values indicate some stimulation effects, while very large positive values reflect significant near-wellbore restriction. The other ranges don’t cover this full spectrum or tend to constrain the magnitude too much.