PTA is an Economics tool when we produce deliverability forecasts. Well test rates (initial) are not the same as steady-state flow rates in the future. Flow rates usually exhibit a decline curve. Given a good synthetic model pressure build-up history match, reasonable analytical results, and valid assumptions about boundaries, a PTA deliverability forecast is generally provided out to twelve months. Longer is easy, and alternate cases can be run for comparison. If a well has near wellbore damage, positive skin, alternate cases can estimate flow rates at various improved conditions (frac’d, acidized, wax solvent). Alternate cases might be run at different drawdown pressures to optimize facilities, contracts, sales, and economics. Long term cases can provide an estimate of economically recoverable reserves (at abandonment pressure).