Experimental and modeling hydraulic studies of foam drilling fluid flowing through vertical smooth pipes

Foam has emerged as an efficient drilling fluid for the drilling of low pressure, fractured and matured reservoirs because of its the ability to reduce formation damage, fluid loss, differential sticking etc. However the compressible nature along with its complicated rheology has made its implementation a multifaceted task. Knowledge of the hydrodynamic behavior of drilling fluid within the borehole is the key behind successful implementation of drilling job. However, little effort has been made to develop the hydrodynamic models for the foam flowing with cuttings through pipes of variable diameter. In the present study, hydrodynamics of the foam fluid was investigated through the vertical smooth pipes of different pipe diameters, with variable foam properties in a flow loop system. Effect of cutting loading on pressure drop was also studied. Thus, the present investigation estimates the differential pressure loss across the pipe. The flow loop permits foam flow through 25.4 mm, 38.1 mm and 50.8 mm diameter pipes. The smaller diameter pipes are used to replicate the annular spaces between the drill string and wellbore. The developed model determines the pressure loss along the pipe and the results are compared with a number of existing models. The developed model is able to predict the experimental results more accurately.