Physical properties of water-oil mixtures involving waxing

Non-Newtonian fluids exist extensively in the oil and gas industry and possess distinct physical properties that differ from those of Newtonian fluids. The multiphase flow involving non-Newtonian fluids have posed a serious challenge to the industry; however, comprehensive information expressing a wider knowledge of the mixture properties have not been well acquired. The focus of this paper is on water-oil mixtures involving petroleum wax, and seeks to highlight the waxing issue which is frequently encountered in offshore oil and gas transport pipelines. Experimental tests are carried out to investigate the behaviour of the water-oil mixture (with wax composition) and examine their fundamental physical and rheological properties. Furthermore, the effect of changes in temperature and varying water volume fraction on the shear rate – shear stress characteristics of the mixture are also considered. Results from this study show that the mixture properties depend significantly on temperature changes, fluid composition and the water content. Investigations also suggest that the phase inversion phenomenon has a significant impact on the shear rate-shear stress characteristics of the non-Newtonian oil/water mixture.