Reservoir sensitivity study of He 8 reservoir from Zichang area in Ordos basin

On the basis of the field outcrop and core observation,through the indoor sensitivity experiment,combining with the casting thin sections,physical properties testing,scanning electron microscopy(sem),mercury injection and other comprehensive analysis of a large number of test data,the study on the reservoir sensitivity characteristics and its formation mechanism was carried out.The study results show that He 8 reservoirs are of medium-to-weak velocity sensitivity,weak water sensitivity,weak acid sensitivity,salt sensitivity,medium-to-weak base sensitive characteristics.The formation of the sensitivity was not only affected by the type of clay minerals content of a reservoir and existing form,but also was associated with complex pore structure at the same time.