رضا آذین

Constant volume depletion (CVD) test is one of the most important experiments that is used for identification of phase behavior of gas condensate fluid. CVD test has an ability to simulate depletion stage and production from gas condensate reservoirs. Before usage of CVD test results require consistency chack and quality control before for simulation, it is necessary to evaluate the consistency and quality of this test. Therefore methods of quality control are essential. One of the main methods for controlling quality of CVD test is material balance. In this method, significant parameters such as density and molecular weight of liquid phase, molecular weight of plus fraction molecular weight in liquid phase and liquid composition of liquid phase (Xi) are calculated in each depletion stage. If calculated liquid composition become negative, the test is known as it is indicated that test is invalid, which is frequently observed in CVD test of gas condensate fluid systems and referred as . This problem is often created due to incorrect recorded data during in this experiment. To remove For removing or reduction of negative liquid composition in material balance, measured exhaust gas mole percentage can be changed, either manually or systematically. But in most cases this method is not practical. In this article, this changes are done by use of PVTi software and implementation of different regression on some samples from supergiant gas condensate reservoir in Middle East