Fractured horizontal well productivity prediction in tight oil reservoirs

Abstract

Horizontal wells productivity prediction and its influence factors analysis have important meanings in development of tight oil reservoirs. The purpose of a reservoir engineering study is to maintain a stable production rate. Although a scientific development plan can benefit yield stability, it needs to match with adjustments of a well production system. Especially for extra low permeability and tight oil reservoirs, an unsteady well production system may increase difficulties of well productivity prediction. Taking a tight oil reservoir in Daqing oilfield as the research subject, on the basis of an unsteady percolation mechanics theory and the superposition principle, a numerical model is built to calculate and analyze the fractured horizontal well productivity. In order to study horizontal well productivity better, a power law exponential decline model is also used to calculate and predict well productivity. Comparing with the numerical model and the power law model, the results show that the numerical model can be used to analyze productivity influence factors, and both models have a good match with actual production data for wells with the stable production system wells. Considering a well's unsteady production system and a model's practicability, the power law model can also be used to calculate and predict horizontal wells productivity in this research oilfield. The results of this study provide a reference for horizontal well productivity calculations and prediction in similar reservoirs.