Drill pipe inclination effects on horizontal wells cleaning process

Hóliver Zambon Zanete¹; Renato do Nascimento Siqueira¹

¹ Instituto Federal do Espírito Santo - Campus São Mateus

doi:10.20906/CPS/COB-2015-1261

Resumo

Horizontal wells are very common in the petroleum industry due to the increase of the wellbore contact area with the reservoir. However, the drilling process is complex and many aspects can affect its performance. Among them, it is possible to quote the drilling fluid, the axial flow, the rotational speed, eccentricity and inclination of the drilling pipe. This work evaluates the effect of the drill pipe inclination on the drilling process performance. The drilling fluid is represented by the power law rheological model with consistency index K = 0.678 and power index n = 0.27. The annular region is 4.9 m long and the inner and outer cylinder diameters are 0.058 m and 0.104 m, respectively. A concentric configuration was used as reference and one side of the drill pipe was displaced in order to promote the inclination of the drilling column, which varied from 0 to 0.004 m/m. For the concentric configuration, the effective viscosity was very small near the walls due to the large shear strain. However, in the central region of the annulus, it increased considerably (µe = 1.2 Pa.s), which is important to carry the cuttings away. For the inclined configuration, the increase in the angle formed by the drilling column with the horizontal plane, changes the flow pattern and decrease the effective viscosity, decreasing the cuttings transport capacity. For the fluid considered, the inclination of the drilling string did not affect the pressure drop due to the small values of shear strain near the walls.

Palavras-chave: CFD; Non-Newtonian; horizontal wells