Global energy demand is rapidly increasing at a rate of 8 between 2004 and 2019, and conventional energy sources are unable to meet this requirement. Therefore, the oil and gas energy industry is working continuously to produce unconventional energy sources such as deepwater oil and gas reservoirs, gas hydrates, and geothermal energy using drilling operations. In the drilled borehole, the stability and integrity issues are encountered that are related to pressure differential generated by the Couette-Poiseuille (CP) fluid flow phenomenon occurred during pipe tripping operation. There is a lack of experimental data to comprehend the impact of CP flow on pressure differential using non-Newtonian fluid in concentric and eccentric annuli, especially in petroleum exploration. Hence, an experimental investigation is performed to replicate the tripping operations during oil and gas well drilling. The investigation provides an extensive understanding of the physical and mechanical characteristics of non-Newtonian fluids under CP flow at varying inner pipe tripping speeds (0.030481�0.21336 m/s), rheological properties, and geometrical dimensions. The results indicate that surge/swab pressure gradient tends to decrease with increasing eccentricity (ε) and increase with increasing diameter ratio (δ) and pipe tripping speed (Vp). Furthermore, the pressure differential rate is considerably high at low tripping speed but reduces at high pipe tripping speed due to the shear-thinning behavior of YPL fluid. The study also reveals that gel strength increases the surge/swab pressure gradient by approximately 18. A multi-variable correlation is developed to predict surge/swab pressure gradient, exhibiting an excellent agreement with experimental data and existing theoretical models. © 2021 Elsevier B.V.