弹性波速径向变化在非常规储层可压性评价中的应用

Application of radial acoustic velocity variation in the fracability evaluation of unconventional reservoirs

非常规储层的开发均需要进行压裂,所以对非常规储层可压性的评价就变得很重要。岩石的脆性是影响储层可压性的重要因素,是优选压裂层位的重要指标。该文在单极子波形正演模拟及波速径向变化计算的基础上,针对非常规储层,应用弹性波速径向变化来评价储层脆性,并分析这种方法在非常规储层可压性评价中的应用效果。通过实例分析可看出,对于相邻两套致密砂岩储层,脆性好的井段压裂后产能也较高,证实了此方法对可压性的分析结果;对于煤储层,煤层段弹性波速降低明显,反映煤层可压性较好,这与煤层段的压裂效果也是相符的。所以,对于非常规储层,基于弹性波速径向变化评价脆性的方法能够很好地反映非常规储层可压性的强弱。

The development of unconventional reservoirs requires fracturing,so it is very important to evaluate the fracability of unconventional reservoirs.The brittleness of rock is an important factor affecting the fracability of reservoir and an important index for optimizing fracturing interval.For unconventional reservoirs,this paper applies the radial acoustic velocity variation to evaluate the brittleness of unconventional reservoir,and analyzes the application effect of this method in the fracability evaluation of unconventional reservoir.It can be seen through the examples,for the two sets of tight sandstone reservoir,the brittleness is better,and the productivity after fracturing is higher,and this confirms the analysis results of this method on the fracability;for coal reservoirs,the radial acoustic velocity in coal reservoir decreases obviously,reflecting the brittleness of coal reservoir,which is also consistent with the fracturing effect of coal reservoir.Therefore,for unconventional reservoirs,the method of brittleness evaluation based on the radial acoustic velocity variation can well reflect the fracability of unconventional reservoirs.