Cuttings Transport: Tripping Analysis Based on a Dynamic Layering Method via CFD

Insufficient hole cleaning is one of the main reasons for pipes stuck in extended-reach drilling, especially while tripping. The mechanism of cuttings transport while tripping is with this investigated. First, a dynamic layering method with the Eulerian-Granular approach is established and verified. The dynamic layering method can simulate the axial movement of the pipe, and the Eulerian-Granular approach can simulate the two-phase flow. Next, the tripping operations of a connector-furnished pipe with and without circulation are simulated, and the sensitive parameter analysis is conducted. The results demonstrate that cuttings dune piles up in front of the connector (lower right corner), and the dune’s height increases with time. Moreover, the cuttings concentration around the connector when tripping with circulation is higher than that without circulation. So, it is safe to use the large flow rate after the cuttings have passed through the connector while tripping. Furthermore, the highest cuttings concentration decreases with the connector’s length, while increases with the connector’s diameter. This exploration is an essential guide to predicting and controlling tight spots while tripping.