储层特别是低渗透储集层是多孔介质,对烃类气体的吸附量很大,而很大的吸附量对气田及凝析气田的开发动态有一定影响。认为:真正的低渗透储集层是由细小的颗粒构成,有许许多多的毛细孔隙,储层介质具有巨大的内比表面积,由于气体分子是紧挨着储集层孔隙表面的,故在气田开发中吸附量的计算至关重要;要计算吸附量,首先要测定吸附等温线,但由于气藏的孔隙细,组分多,吸附等温线十分复杂,测定十分困难,所以,建立烃类气体在气藏中的吸附等温线计算模型十分必要。在严格的表面化工热力学的基础上,建立了吸附等温线的计算模型,并对实例凝析气藏的吸附等温线进行了计算,获得了满意的结果。

The calculation of absorption is very important durin g the research and development of coal-bed gas.And a lot of researches have bee n done in the last few years. To the sandstone reservoir, we did not look more t he influence of absorption upon the performance of natural gas reservoir. But  o n the one hand  the real reservoir is made up of tiny grains and tiny pore so th at this makes it have huge  Specific Area Measurement; on the other hand, the mo lecular impinge on the surface of reservoir. So the reservoir medium will absorb  the hydrocarbon gas very intensively at the same. Well then, the influence of a bsorption on the reservoir performance cannot be ignored. If the influence of ab sorption is considered we must have the  absorption isotherms. However the measu re of Absorption isotherm is very difficult because of  tiny pore   and more com ponents in reservoir. So it is very necessary to establish the model of calculat e absorption isotherm. The model of calculates absorption isotherm based on the  surface chemical engineering thermodynamics are established and the absorption i sotherm of an example were calculated using this model. 