Study on Dynamic Cuttings Transport Model of Extended Reach Well and Its Application in Fields

Hole cleaning is a one of key technologies of extended reach drilling, the core of which is cuttings transport research. Based on the theory of solid-liquid flow, a three layers dynamic cuttings transport model for all sections of ERW (extended reach well) is developed and the mechanisms of suspension, rolling and sliding of cuttings, the relative velocity between solid and liquid in suspension layer and the effect of drillpipe rotation are all taken into account. The model can be used for calculation and simulation of all sections and processes on actual drilling and circulating conditions. This model have achieved successful application in fields with high calculation accuracy. It can be used to calculate and analyze the cuttings bed height, the minimum pump rate for hole cleaning, pump pressure and ECD (equivalent circulating density), which provides an effective tool for the hydraulics calculation and design and hole cleaning monitoring for ERW.