PTA is a Completions and Workover tool when we test for skin — near wellbore damage. Oil well productivity (IPR), gas well deliverability (AOF), and water well injectivity, are all a function of flowing conditions between the rock matrix and production tubing. Open holes, sand screens, slotted liners, or perforations: the subsurface environment is prone to damage. Damage starts when we drill a well (glazing, mud invasion), accelerates during completion (kill fluids, lost circulation), and levels off for the long term under production (fines, wax, scale). Positive near wellbore skin (s) damage is obviously not optimal for operations, so it’s important to monitor and test underperforming locations. A good time for asset optimization testing is plant turnaround. Workover and stimulation programs should include follow-up testing for confirmation and confidence in treatment programs and results.