低渗透储层气藏烃类气体吸附等温线计算模型的建立及其应用

THE FOUNDATION AND APPLICATION OF ABSORPTION ISOTHERM CALCULATE MODEL IN NATURAL GAS RESERVOIRS

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 during the research and development of coal-bed gas.And a lot of researches have been done in the last few years. To the sandstone reservoir, we did not look more the influence of absorption upon the performance of natural gas reservoir. But on the one hand the real reservoir is made up of tiny grains and tiny pore so that this makes it have huge Specific Area Measurement; on the other hand, the molecular 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 absorption on the reservoir performance cannot be ignored. If the influence of absorption is considered we must have the absorption isotherms. However the measure of Absorption isotherm is very difficult because of tiny pore and more components in reservoir. So it is very necessary to establish the model of calculate absorption isotherm. The model of calculates absorption isotherm based on the surface chemical engineering thermodynamics are established and the absorption isotherm of an example were calculated using this model.