Pars Welltest Analyser (PWA) is a comprehensive package for analyzing and history matching transient well test data. The applied analytical methods in PWA and also numerical methods in our future development plan help engineers to interpret reservoir flow characteristics and predict future production based on well test analysis results. PWA’s Powerful graphical user interface makes it easy for users to move around and assimilate the program options. The Main Features of this package includes: -Quick and easy data entry -Comprehensive correlation packages of rock & fluid properties -Full set of diagnostic analysis tools -Sensitivity analysis -Test design -Simultaneous view of multiple analysis -Robust input data handling and import capability -Fast and accurate results using a powerful optimization engine