Simulation-based three-dimensional model of wellbore stability in fractured formation using discrete element method based on formation microscanner image: A case study of Tarim Basin, China

Wellbore instability in fractured formation is a major challenge in drilling engineering, especially in the oil and gas energy sector. This study aims to analyze wellbore stability in fractured formation using discrete element method. A novel fractures modeling method by using formation microscanner images (FMI) and image processing was proposed. Three wellbore models with different fracture structures, and a no fracture model are developed to simulate the wellbore drilled in X well, Tarim Basin, China. Different drilling fluid densities are applied to the four models. Failures and deformation of wellbore models are investigated. Large amounts of displacement and yielded zones around the wellbore were observed in the high and low dip intersecting fractures models. And fluid density has few effects on the wellbore stability. High dip fracture is considered a major factor in wellbore instability. The high drilling fluid density performed better in the low dip fracture model, and the low drilling fluid density performed better in the vertical fracture model and intact model. The proposed modeling method and findings have important implications for understanding the wellbore instability in fractured formation. •A new modeling method of wellbore stability combines discrete element method and formation microscanner image.•High dip fracture is considered a major factor in wellbore instability.•Drilling fluid density has a poor effect on wellbore stability in high and low dip intersecting fractures formation.