It is known worldwide that temperature has decisive influence in determining the behavior of a drilling fluid, and it is evidenced in this work by estimating the rheological properties of a Drilling Fluid as function of Temperature and analyzing how the behavior of the fluid appear affected as temperature increases. A secondary aim of the research is to study how changes in temperature and therefore of Rheology, may affect some relevant hydraulic parameters, in the hydraulic circuit of a well in the phase of progress.
Initially, several tests were carried out to study the fluid and consequently the data obtained from the tests were processed to compute the parameters of interest. Subsequently, the first attempt was to understand what rheological model, including those proposed in the literature, would be more suitable to represent the behavior of the fluid. Afterwards, the rheological parameters were calculated, using different methods, and highlighting not only variation of each parameter as function of temperature but also the differences between the computational methods, highlighting the differences. Lastly it was studied the efficiency of the hydraulic system giving attention to the parameters which appeared sensible to the temperature variation.
The results showed the Temperature has a big impact on Rheology and sometimes increase in temperature may produce a complex behavior, which can be detected only with an appropriate discretization of the measurements. This behavior may lead as consequence problems in the identification of an appropriate representative mathematical model and therefore high uncertainty in the calculation of rheological and hydraulic parameters. Another important conclusion of this research concerns the fact that many classical formulas, commonly used for the calculation of the rheological parameters were found to be rather approximated and not reliable, even when the fluid was not showing complex behavior. Finally, some simulations were performed which showed that the effect of temperature plays indirectly a key role in the efficiency of hole cleaning.
