应力敏感裂缝性油藏不稳态压力动态分析

在试井分析中通常都是假设岩石特性为常数,这个假设条件在许多油气藏的试井分析中取得了很好的解释结果。但是,大量的室内实验发现裂缝性油气藏和致密砂岩油气藏都为典型的应力敏感油气藏,即随着开采的进行,储层的孔隙压力降低,从而导致地层中的有效应力增加,储层渗透率的大幅度降低,因此,必须在试井解释中考虑地层应力对岩石特性即渗透率,孔隙度的影响。根据实验研究结论,建立应力敏感裂缝性油藏的渗流数学模型,并通过数值Laplace反演求解形成了新的试井分析,分析研究其典型曲线特征及其对压力恢复数据解释的影响。

Pressure Transient Analysis for Naturally Fractured Reservoirs with Stress Sensitivity

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.