Currently, many adsorption experiments of methane on shale have been done to understand adsorption characteristics of methane on shale, but those experiments’ pressure and temperature are far less than reservoir pressure and temperature; therefore, we carried out the experiments of methane adsorption on shale at 75.6°C and 95.6°C with 0–50 MPa pressure range to study the adsorption characteristics of shale under reservoir condition. We also build a new method to calculate the real (absolute) adsorption of methane on shale. Results present that the characteristics of excess adsorption isotherm under high pressure is different from the characteristics of excess isotherm under low pressure; adsorption obtained by adsorption experiment increases with pressure going up until reaching a peak and then declines with further increase in pressure. We build a new method to calculate the absolute adsorption by assuming that the adsorption phase volume approximately equals to the total volume occupied by adsorbed molecule, and the results calculated by our method show this method is reasonable and effective.

中文翻译：

---

一种新方法计算高压甲烷在页岩上的绝对吸附量

目前，已经进行了许多页岩甲烷吸附实验来了解页岩甲烷的吸附特性，但这些实验的压力和温度远低于储层压力和温度；为此，我们开展了75.6℃和95.6℃、0～50 MPa压力范围内的甲烷吸附实验，研究了储层条件下页岩的吸附特性。我们还建立了一种新方法来计算页岩上甲烷的实际（绝对）吸附量。结果表明，高压下过量吸附等温线的特征不同于低压下过量吸附等温线的特征；吸附实验得到的吸附量随着压力的升高而增加，直到达到峰值，然后随着压力的进一步增加而下降。