Below is a Bourdet analysis of CSG Well in Australia, The data is very clear, as this was a build-up analysis. Build-up data tends to be very high resolution, and low noise resulting a very clear definition of radial flow.
Given the large separation of rate normalize pressure data and its Bourdet derivative, it is clear there is an effective or apparent positive skin (refer to Wellbore Skin and Formation Damage and Bourdet Sensitivity to Skin .
An injection and fall-off test was performed, which is the likely cause of the downward trend of the derivative (I.e., the pressures have become stabilized).
