修正的页岩气等温吸附模型

Modified Isothermal Adsorption Model of Shale Gas

针对Langmuir等温吸附方程及修正的双朗格缪尔模型(D-Langmuir)在研究非均质吸附介质页岩等温吸附时,对实验数据拟合精度及稳定性不高的问题,展开了新的等温吸附方程研究,研究中将吸附系统内不同吸附介质的吸附特征转化为系统内压力的实际作用效果,对D-Langmuir模型进行压力修正,得到新的、适用于多吸附介质的P-Langmuir等温吸附模型。将以上模型应用于渝东南渝页1井共21个样品的等温吸附实验数据的拟合,结果表明:Langmuir模型平均误差在-0.012 0~80.021 2 m^3/t;D-Langmuir模型平均误差在-0.003 64~0.021 20 m^3/t;P-Langmuir等温吸附模型相关系数的平方0.992 5≤R^2≤0.999 8,平均误差在-0.003 25~0.003 21 m^3/t,相比于Langmuir方程及D-Langmuir方程,P-Langmuir模型拟合精度更高,稳定性更好,对更准确地评价页岩吸附气量具有一定的实际意义。

When using Langmuir model and modified double Langmuir model on heterogeneity medium shale isotherm ad- sorption, the experimental data fitting accuracy and stability is not high. We launched a study on new isotherm adsorption equation. The study transforms the adsorption characteristics of different adsorption media within the adsorption system into the actual effect of system pressure, and corrects the pressure for double Langmuir model, getting a new P-Langmuir isotherm adsorption model, which is suitable for multi-adsorption-media system. The model is applied to fitting adsorption isotherm experimental data of 21 samples of Yuye 1 shale gas well in the Southeast of Chongqing and the result shows that average errors of Langmuir model are between -0.012 8 m^3/t and 0.021 2 m^3/t, D-Langmuir model between -0.003 64 m^3/t and 0.021 2 m^3/t, and all the values of the correlation coefficient R2 of the P-Langmuir model are between 0.992 5 and 0.999 8, and that average errors of 21 samples are between -0.003 25 m^3/t and 0.003 21 m^3/t. Compared to the Langmuir equation and double Langmuir equation, P-Langmuir model is of higher fitting accuracy and better stability, has some practical significance for more accurately evaluating shale gas adsorption.