A family of pressure and production decline curves are generated for wet-gas sands with closed outer boundaries. Wet-gas sands are characterized as gas reservoirs which produce substantial amounts of water together with gas. Production of water introduces complications when practicing engineers use decline curves designed for gas reservoirs in which gas is the only flowing phase. This usually translates to over estimation of the production performance of the reservoir.

In this paper a series of pressure and production decline curves which accounts for the water production in wet-gas sands is presented. These decline curves provide a simple way of extracting valuable information from available data, using graphical methods and simple calculations. The proposed decline curves are generated for a radial system with closed outer boundary with one centrally located well which fully penetrates the formation. The application of the proposed decline curves is illustrated through a series of examples.

In the case of constant pressure inner boundary, production decline curves are generated for different ratios of sandface pressure and initial formation pressure, and in the case of constant flow rate inner boundary, pressure decline curves are generated for different initial formation pressures. The proposed decline curves covers a broad spectrum of reservoir extents and have proven to be unique for a wide range of fluid and formation parameters.

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