页岩气储量计算的新方法

New methods for shale gas reserves calculation

分析以有的成果和文献后认为,传统方法计算出的页岩气储量存在被无意识扩大的可能。为此,考虑页岩储层孔隙尺寸对页岩气地质储量的影响,根据页岩气物理特性和地球化学特性提出了一种基于孔隙尺寸计算页岩气地质储量的新模型,使页岩气地质储量的计算精度较传统方法提高了20%。实例计算结果表明:①在孔隙半径为2nm时,页岩气地质储量达到最大峰值,当孔隙半径大于6nm后,页岩气储量不随孔隙半径的增加而增加;②储量计算模型的建立和修正十分必要,没有任何两个地方的页岩气储量模型是完全一样的,因此很有必要建立一个国内页岩气储量计算的数据库。

It has been analyzed that the traditional methods for shale gas reserve calculation will probably result in exaggerated estimation.In view of this,with the influence of shale pore sizes on geological reserves taken into consideration,a new model is proposed for the reserve calculation based on pore sizes according to the physical and geochemical properties of shale gas.With this new method,the calculation accuracy is increased by 20 percent compared to the traditional methods.The case study shows that when the pore radius is 2 nm,the shale reserves reach the maximum value,but when the pore radius is larger than 6 nm,the reserves will not change along with the increase of the pore radius;it is necessary to establish and revise the model of reserve estimation because no reserve models are the same in any two different areas,and thereby it is strongly recommended to build a data base for reserve estimation in China.