Reserves producing level analysis of multilayer gas reservoir in the Sebei gas filed

The Sebei gas field of Qaidam basin,with 54-90 gas-bearing layers,is a typical multilayer gas reservoir,and systematic analysis of production performance shows that there are big differences among interlayer reserves producing level.Methods of experimental simulation,gas reservoir engineering and numerical simulation have been adopted to study the influences of reservoir heterogeneity,interlayer reserve distribution and gas well water breakthrough on reserves producing level.The results show that interlayer heterogeneity is the main influencing factor on the reserves producing level of multilayer gas reservoir,with higher permeability contrast,worse reserves producing of low-permeability layers.For this kind of gas reservoir,the reserves producing level of multilayer gas reservoir can be improved by rational division of commingled layer series,perforation optimization,and production allocation optimization.