Modeling of Foam-Assisted Wellbore Cleanup and Drilling Processes with Both Dry- and Wet-Foam Rheological Properties

Abstract

As advanced drilling technology gains more popularity in the development of unconventional reservoirs and deepwater fields, the demand for an improved drilling hydraulics modeling escalates today. The situation is also true for foam applications that have long been used as a useful means of downhole cleaning and underbalanced drilling methods. This study investigates how a new foam model, recently developed by Wang et al. (2017), can be applied to a wide range of hole cleaning and drilling scenarios. The model combines rheological properties of wet foams and dry foams by using 9 model parameters (3 to define the range of gas and liquid flowrates and corresponding frictional pressure losses of interest, 4 to fit the power-law rheology of wet and dry foams, and last 2 to capture the sensitivity of foam rheology to gas and liquid rates). These scenarios consider foam circulation into 10,000 ft long wells at different inclination angles with a long vertical, inclined, or horizontal trajectory. The results from this new method are compared with two existing foam modeling techniques, so-called Chen et al.'s model (based on the correlations for wet foams only) and Edrisi and Kam's model (based on wet- and dry-foam rheological properties with 5 model parameters). The results show that, with or without formation fluid influx, the new foam model demonstrates the robustness of the new modeling technique in all scenarios capturing foam flow characteristics better, whenever the situation forms stable fine-textured foams or unstable coarse-textured foams.