| dc.description.abstract | Although the use of compressible drilling fluids is experiencing growth, the flow
behavior and stability properties of drilling foams are more complicated than those of
conventional fluids. In contrast with conventional mud, the physical properties of foam
change along the wellbore. Foam physical and thermal properties are strongly affected by
pressure and temperature. Many problems associated with field applications still exist,
and a precise characterization of the rheological properties of these complex systems
needs to be performed. The accurate determination of the foam properties in circulating
wells helps to achieve better estimation of foam rheology and pressure.
A computer code is developed to process the data and closely simulate the pressure
during drilling a well. The model also offers a detailed discussion of many aspects of
foam drilling operations and enables the user to generate many comparative graphs and
tables. The effects of some important parameters such as: back-pressure, rate of
penetration, cuttings concentration, cuttings size, and formation water influx on pressure,
injection rate, and velocity are presented in tabular and graphical form.
A discretized heat transfer model is formulated with an energy balance on a control
volume in the flowing fluid. The finite difference model (FDM) is used to write the
governing heat transfer equations in discretized form. A detailed discussion on the
determination of heat transfer coefficients and the solution approach is presented.
Additional research is required to analyze the foam heat transfer coefficient and thermal
conductivity. | en |
