Abstract: This paper raises a theoretical model, which considers the effect of adsorption on reserves in place. The Movable Adsorption Model in chemical industry is adopted to calculate the adsorption of gas in gas reservoirs. At first, we simulate the single component adsorptive experiment data so as to gain some basic parameters and apply the experimental data of a two components system to exam the adsorptive model. Then we gain the fundamental parameters on the basis of simulating the real single component adsorptive experiment data or the spread theory of adsorption of single component in more actual porous media by Clark, a actual multi Component natural gas
system and a gas condense system are calculated respectively as examples. At the end, we give the tendency and extent of the effection reserves in place under different formation conditions such as systems, porous media and others.

Key words: Absorption, Gas reservoir, Reserve