History Matching means comparing the real observations with the simulated ones. Production, water-cut, GOR etc. are suitable for direct comparison. But the comparison of bottomhole pressures is difficult because these values depend on the method and time of observation. Bottomhole flowing pressure can be tuned by modification of near well properties. But the static bottomhole pressure can not be tuned like this. The static bottomhole pressure per definition is the average pressure of the drainage area. This can be measured by buildup test, utilizing Horner & MBH plots. This sequence is seldom reproduced in a simulation run; and besides any coarse grid is not suitable to reproduce the transient pressure behaviors of a radial flow. This thesis describes the methods how these well static pressures are determined in the commercial software, discuses their theoretical backgrounds and compare their results. The applicability and limitations of the different methods are demonstrated in the examples. Three software packages were used in this project: SURE, ECLIPSE and HRC (Prof. Heinemanns Research Code). Investigating the HRC method showed that HRC gives good comparable results under the same conditions as SURE and ECLIPSE. Further investigations showed that by changing the properties, the calculated pressures in time will vary largely. These results may have drastic differences with a possible buildup test. These results opened a new perspective for further researches.