Methodologies for analysis of productivity decline: A review and application

• We analyzed the production decline in a geothermal well.
• Four different methodologies for analysis of the wells production decline were applied.
• There is a correlation between increase of damage effect and the decrease of productivity.
• The knowledge of the decline production allows modify the exploitation designs to improve the wells performance.

This work emphasizes the convenience of combining several methodologies to assess decline analysis in wells. We show that using different techniques, the reservoir characterization diagnoses are reinforced. Four of the different methods associated to decline analysis in well productivity are shown. The governing equations, used in methodologies of analysis decline, normalized flow and increase of the damage effect, were reviewed. The diagnosis applied to identify the decline model type, using the classical methodology of analysis, was shown. The comparison between predicted and measured values using normalized flow methodology provides reliable results. Through determining the damage effect technique it was found a direct correlation between the productivity decline and the increase in damage value along the productive life of the well. Geochemical variations in fluids can also provide support in decline rate studies of wells. The methodologies reviewed in this work help in looking for integral solutions to improve the reservoirs productivity.