Abstract: Effect of wellbore storage exist commonly in a long time after well testing in Baolang oilfield,a low permeability reservoir with relatively high GOR,leading to a long time needed for conventional pressure buildup test operation.Variable rate test method was utilized in Well B103in order to solve this problem.Field test calculation and analysis revealed that calculation results were accurate,testing technologies and analytical proce-dures were simple and it was suitable for field applica-tion.Open well test operation remarkably reduced effect of wellbore storage,shortened test time and fundamen-tally elim inated the impacts of well testing on produc-tion,thus im proved economic benefits of well testing and development man agement levels.