Beyond the Wax Concentration; How Micro/Macro Wax Ratios Change Thermal, Rheological, and Morphological Properties of the Waxy System

Knowledge of the rheological and thermal properties of wax oils is central to understanding their behavior and their impact under the diverse operational conditions to which these oils are subjected in the O&G industry. A better understanding of the compositional effects on the behavior of wax deposits is essential for the improvement of prediction and mitigation techniques for this type of phenomenon. In this study, we evaluated different model systems based on micro/macro wax and how these combinations affect the thermal and rheological properties. As expected, combinations richer in micro wax showed higher wax appearance temperature and gelation temperature (Tgel), but gel strength is inversely proportional to micro wax content, as evidenced by rheological tests. The morphology and aspect ratio of the crystals are parameters that directly impact the rheological properties of the formulations; crystals with a high aspect ratio and needle morphology tend to form stronger gels due to greater interaction between crystals. The rheological and morphological tests suggest that aggregates of micro wax crystals can weaken the three-dimensional network of macro wax crystals and consequently reduce the yield stress. The results suggest that the addition of micro wax can minimize the pressure required for oil field flow restart.