Which parameter is not typically obtained from a stabilized well test?

• A. Reservoir Porosity
• B. Average Reservoir Pressure
• C. Well Productivity or Injectivity Index
• D. Drainage Area Information

Answer: (A)

In a stabilized well test, the focus is on how fluids move around the well when production (or injection) is kept at a steady rate. From the steady-state pressure and flow data, you can determine the average reservoir pressure, the well’s ability to produce or inject fluids (the productivity or injectivity index), and you can gain information about the drainage area—the portion of the reservoir contributing flow to the well—by analyzing how the pressure field develops around the well.

Porosity, however, is a storage property that describes how much pore space the rock contains. The steady-state pressure response used in stabilized tests doesn’t directly reveal pore volume or storage; porosity is typically determined from core samples and petrophysical logs (like density-porosity or NMR measurements), not from a stabilized pressure-flow test. That’s why porosity is not typically obtained from a stabilized well test, whereas reservoir pressure, productivity/injectivity, and drainage-area information are.