The rheology of a packer fluid (PF) is the most crucial aspect prompting the efficacious well completion effectiveness. In the drilling industry, a high-density, solid-free, low viscosity, and alkaline pH packer fluid is a big advancement and requirement. Here, we develop a magnesium bromide as an effective solid-free, high-density packer fluid (HDPF) for oilfield applications. We believe that investigating the rheological parameters such as shear stress, yield point, plastic and apparent viscosity, and gel strength 10 s and 10 min at a varying temperature of 84–192 °F is essential for optimizing the rheological performance. In order to enhance the completion efficiency, our work is more focused on overcoming the rheological and density limitations of existing traditional packer fluid. Our results show that the packer fluid has a low value of plastic viscosity (1.95–7.05 cP) and also exhibits a high density of 13.41 lb/gal, a specific gravity of 1.61. We have reported the pH at the alkaline region (pH 7.14) with solid-free. Here, we have investigated the Bingham plastic rheological model and Herschel Bulkley model parameters with experimental rheological data, and it is adaptive to novel packer fluid to predict the rheological parameters. Conspicuously, the rheological models, along with data analysis, have enormous possibilities in envisaging real-time quantification of shear stress and viscosity to enable the user to monitor and evaluate a suitable packer fluid in oilfield applications.