A New Deliverability Testing Method for Gas Condensate Wells

Abstract

In the process of well testing on gas condensate well, if the condensate liquid retrogrades from gas phase, which will adhere to the surface of the rock, the key reservoir parameters would vary, such as the permeability and the skin factor. The changes of reservoir parameters could affect the deliverability of a gas condensate well, by changing the coefficients of A and B in the deliverability equation. These changes make it inapplicable to use the deliverability equation for a conventional gas well to interpret the deliverability of a gas condensate well. In view of the problem above in the process of well testing on gas condensate well, the model in this paper was built up in view of different pressure region, and could reflect the deliverability equation under the specific testing condition, so it could interpret the deliverability of a gas condensate well under different production stages. A new method to model and construct a deliverability equation with variable coefficients or many independent deliverability equations, which can represent the performance of well, was put forward in this paper. Through applying the deliverability test method put forward in this study to a case, results obtained from this method keep consistent with the real testing data, so the deliverability of a gas condensate well obtained by using this method in different process of production can be correctly evaluated. The created deliverability equation could reflect not only the characteristics of gas reservoir testing and dynamic performance, but also four-dimensional changes of rock properties and flowing parameters of reservoir fluid, so the well performance in the future could be more accurately predicted.