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Lack of long-term production data is one of the major challenges when performing analysis for tight gas reservoirs during appraisal phase. For low-permeability liquid-rich gas and gas condensate reservoirs, fracture performance will be severely affected by condensate banking as soon as dew point pressure is reached in the vicinity of the wellbore. This makes the evaluation of fracture effectiveness and potential connected volume more challenging. Although numerical simulation can account for complex PVT, reservoir and fracture characteristics and by far the most rigorous method for forecasting, it cannot be applied to all wells due to lack of analysis time and supporting data. Therefore, a more robust methodology is required to analyze production data for a limited test period during the development phase. This paper entails an efficient and robust methodology that was applied to over 80 wells in less than a few weeks for performance evaluation, history matching and forecasting. The field in this study is a layered tight gas reservoir in the Middle East, which is currently undergoing development after an extensive appraisal plan. Most of the wells are single staged vertically fracced with their performance being significantly in comparison due to the hydraulic fracturing performance, rock quality, gas richness and operating conditions. With over 100 wells planned to be drilled in this field, it is vital to analyze the existing well performances and establish a workflow emphasizing on the near wellbore region for a robust forecasting methodology for this tight liquid-rich reservoir. |
