The Study On Percolation, Well Test Analysis Of Condensate Gas Well

The research on the laws of percolation, well test interpretation of gas condensate system is always the frontal study of condensate gas reservoir exploitation. But it is most difficult and hard. Liquid dropout naturally occurs with reservoir depletion below the dew point, which differs from dry gas. And the dropout liquid—condensate oil will cause condensate blockage. That will result in the great decrease of deliverability. On the other hand condensate is generally viewed as an immobile phase so that the dry gas flow equation is frequently used to analyze gas condensate well test. Those conventional ways are not agree with the true flow situation of condensate reservoir, so the ways are doubted and criticized now. Modern well testing analysis has very important role in reservoir description, numerical simulation researching the condensate gas well characteristics and flow disciplinarian. And an accurate evaluation of well test is extremely important for the planning and development of gas condensate reservoir. Therefore, there is the strong need to develop a new and rigorous equation to express more closely the real gas-condensate flow in porous media. In this paper, the foregoing problem is expected to be resolved. The main contents of this paper are as following: By studying and analyzing the mechanism of phase equilibrium and percolation of condensate system, the description of flow performance of gas condensate is presented in detailed. On the basis of the detailed description of flow performance of gas condensate, a definite solution problem of gas condensate composite reservoir multi-flow is formulated. Subsequently the detailed solution procedures are described. Three-region composite gas-condensate wells well test model has been established and worked out on the base of the solution of the flow equation. By defining a two-phase pseudo-pressure function, the differential equations of percolation of gas and liquid are linear transformed. All well test model are linear transformed. And dimensionless parameters aredefined. The dimensionless well test analysis models are solved and the dimensionless pseudo-pressure solution in Laplace space are achieved. Finally the solutions are numerically inverted. Different outside boundaries and the effect of wellbore storage , skin and wellbore phase segregation are considered in the model and the subsequently type curves of modern well test analysis are plotted. The models and the approaches of well test interpretation are correct by examples testing and verifying. On the basis of the results of the well test analysis, this paper gives reasonable approaches of predicting pressure distribution, condensate oil saturation distribution, frontal radius of two-phase flowing region and relative permeability distribution etc.In the summary, all the theories and approaches presented in this thesis reflect the actual innate situation of the percolation of condensate oil and gas. They have momentous engineering significance, and can guide developing the condensate gasreservoir more reasonably and scientifically.