Abstract: Based on the continuous point source superposition theory, a mathematical model to describe the pressure distribution in in-clined well bore with uniform fluid flow rate has been estab-lished. This model can be used to investigate various well bore configurations, such as perforation length, location, well bore
angle and permeability variation. According to the Stehfest’s numeric inversion algorithm, the type curve of the pressure drawdown provides a way to conduct well test interpretation and deliverability prediction. On the Log-Log plot, there are two pieces of pressure-derivative horizontal segments. The first rep-resents the early radial flow and the second indicates the pseudo
radial flow. Under the same perforation interval condition, in-clined or horizontal well is easier to allow fluid flow than vertical well, which can make full use of the reservoir energy.

Key words: Well test Interpretation, Inclined well, Lat-eral well, Transient pressure data, Mathematical model