The gelling oil with high wax content can be used to simulate the wax deposit inside the pipelines. In this paper, a new yield stress measurement method for gelling oil with high wax content was presented. It has a wider measurement range compared to regular measurements. Thus, the yielding behavior of oilwax mixture in low temperatures was further studied. In particular, the effects of melting temperature, standing time in melting and measurement temperatures on yielding behavior were presented for oilwax mixture. It is found that high melting temperature contribute to a low yield stress. The yield stress of gelling oil increases with the increase in standing time in melting temperature. Within 5 h standing time, the yield stress is kept constant. In addition, the effect of standing time in measurement temperature on yielding behavior can be ignored. The yield stress remains basically unchanged while standing time in measurement temperature is more than 30 min. These conclusions are of great significance in preparing gelling oil with high wax content. It forms the basis for exploring the wax breakage and removal mechanisms during pipeline pigging.

At present, the operating inlet oil temperature to the pump station along Asai pipeline is much higher than the gel point of the crude oil. And the pigging frequency is much higher. There is much waxes removed from the pipeline during the pigging operation. It not only blocks the inlets of heating furnace, but also consumes more thermal energies. In this paper, the wax deposition profiles of the crude oil along Asai pipeline at different inlet temperatures under normal conditions were predicted by using the unified wax deposition model, and also the wax deposition distribution under the condition from damaging thermal insulation was also examined. The prediction results show that the wax deposit mainly accumulated in the inlets of the pump stations. On this basis, a new pigging program involving pigging frequency was proposed, and the same time the inlet oil temperature was also optimized to be a lower value. In winter, the inlet oil temperature is advised to be 40 ℃.While in other seasons, the temperature is 35 ℃. The prediction results were compared with the field data, the relative average error is 9.49%.