Abstract:

The assumption of constant rock properties in pressure transient analysis gives good results in many oil and gas reservoirs. However, a lot of experiments indicate that fractured reservoir and low permeability reservoir are typical stress sensitive zone. The permeability decreases with decreasing of pore pressure and increasing of effective stress in oil field exploitation. So changes of permeability and porosity with stress should be considered in well test interpretation. According to results of experiment, this paper presented a mathematics model of fractured reservoirs with stress sensitivity and obtains type curves through by numerical Laplace inversion. This paper also discussed pressure transient and characteristics of type curves, and investigated stress impacting on buildup interpretation.

Key words: transient well testing, stress sensitive, typical curve