Volume 40: Energy Transitions toward Carbon Neutrality: Part III

A oil-water-gas three-phase flow model for flowback and early-production prediction of multi-fractured horizontal wells in lamellar shale reservoirs Langyu Niu, Linsong Cheng, Zhikai Wang, Pin Jia, Yucheng Wu

Abstract

Some of the beddings in lamellar shale oil reservoir are opened and intersected with the hydraulic fractures, result in orthogonal fracture networks, after hydraulic fracturing. Which make it difficult to interpret properties of fractured reservoir, and affecting the accuracy of production prediction. In this work, a new semi-analytical model is developed specifically for modeling oil-water-gas three-phase production during flowback and early-time production for lamellar shale oil reservoirs. Two flow regions are assumed: opened beddings and matrix, which is considered as dual-medium model, including shale matrix and unopened beddings. A semi-analytical solution method based on dynamic drainage area (DDA) concept is used to solve the mathematical model, in order to improve the accuracy of initial time steps. Stress-dependent and saturation-dependent properties of fractures and matrix are handled in the solution. The robustness of the innovative model is tested through comparison with rigorous numerical model. Based on the proposed model, the influencing factors of three-phase flowback performance for multi-fractured horizontal wells in lamellar shale oil reservoir are clarified. The model in this study provides a foundation for efficient automatic history matching.

Keywords Shale oil reservoir, Multi-phase flowback and early production, Mathematical model