Visualization of Displacement Flows in Oil Well Construction Operations

Fluid displacement in well construction operations is of critical importance in the field and generally involves complex situations, both in terms of geometry (e.g., eccentric annuli and contractions and expansions in the thickness of annuli) and fluid behavior, as these operations typically involve non-Newtonian fluids (Frigaard, 2017a, 2017b; Abreu, 2016, Varges et al. 2020, Tobar et al. 2022). As such, analyzing problems such as casing cementing in enlarged sections, fluid displacement in horizontal and inclined wells, and plug placement processes require a complex and extensive parametric analysis (Moises, 2016, 2014a, 2014b). Moreover, due to their non-trivial nature, experimental visualization emerges as a valuable tool for analysis. The first challenge in the above-mentioned problems lies in the rheological characterization of the fluids employed in oil well operations (Marchesini, 2019; Rodrigues, 2017; Pinheiro, 2016; Varges et al. 2019; Varges et al. 2018; Costa et al. 2023). Drilling fluids, cement slurries, and other suspensions and emulsions, which mechanical behavior is typically non-Newtonian, present properties that are directly related to their stability during specific applications (Varges, 2017). One example is shown in Figure 1, where the visual appearance of a drilling fluid over time is presented. Figure 2 presents the rheological properties of the same fluid, including its storage and loss moduli. A supernatant layer is observed to increase significantly over time, while the storage modulus grows in the lower regions of the reservoir due to sedimentation. It can be observed that the storage and loss moduli increase with time, due to particle agglomeration and sedimentation. Figure 3 shows microscopy images of the fluid immediately after preparation (a) and two years later (b), clearly illustrating increased particle agglomeration.