1.1 Oil Based Drilling Mud System Rheology
The design of an effective drilling mud rheology system means that the
drilling mud has been conditioned to act properly despite terrible
circumstances such as a modification in the rheological formation of the
mud, extreme temperatures and pressures. The paper aims at studying the
rheological properties of oil based drilling fluids using a lab mad
model and a drill bench simulation after which its use in pressure
control and well stability maintenance would be analysed. In order to
achieve this, a drilling mud sample was developed from scratch to be
used in the experiment. The characterization of rheological properties
was started since schwedoff in 1890 who worked on colloidal gelatin
solutions from which he discovered that the torque experience in a
drilling mud system was not proportional to the angular velocity. This
contradicted newton’s theory hence it was concluded that drilling muds
were non-Newtonian fluids. Trouton used the yield stress value in 1904
to achieve a value that matched the flow rate proportionally while in
the years 1922, 1925 and 1926; Bingham, Ostwald, Herschel and Bulkley
respectively continued to develop on the notion from schwedoff about the
non-Newtonian nature of drilling muds. The use of factors such as gel
strength, yield stress, viscosity, and shear stress which can only be
obtained from drilling mud experiments are used to develop models which
are compared to the previously listed rheological models and this is
necessary for the successful characterization and study of the
rheological properties of emulsion muds and their use for pressure
control.