Hybrid Forecasting Methods for Multi-Fractured Horizontal Wells: EUR Sensitivities

In this paper, the sensitivity of expected ultimate recovery (EUR) for horizontal wells with multiple fractures to decline exponent is studied using the simplified forecasting method introduced by Nobakht et al.[1]. This is very important from the reserves evaluation perspective due to uncertainty in decline exponent, b. This uncertainty is caused by many factors like desorption and reservoir/ completion heterogeneity. It is found that in case of timebased forecast (duration of forecast is specified), the ratio of EURs for two different specified values of decline exponent depends on the ratio of economic life time of a well to the duration of linear flow. On the other hand, this EUR ratio depends on the ratio of rate at the end of linear flow to economic rate limit for economic limit-based forecast (economic rate limit is specified). Key words: EUR sensitivities; Multi-fractured horizontal wells; Hybrid forecasting methods