Abstract: The partial pressure maintenance and cyclic gas injection processes were used for development of Yaha 2-3 gas condensate reservoir in Tarim oilfield. But in past years, the pressure monitoring data showed that the reservoir pressures of build-up test data from gas producer were higher than that of build-down test data from gas injector, allowing the related performance analysis to be difficult. This paper analyzes the field testing data, finds out the reasons for abnormal formation pressure and makes corrections to them in order to attain reliable formation pressure. Such a big problem appeared by formation pressure test in past years has been solved, being of more significance for scientific management of the gas fields.

Key words: pressure build-up test, pressure build-down test, well interference, cyclic gas injection