关键词: 石蜡沉积, 临界蜡张力, 模拟研究, 生产工况, 井筒, 石蜡沉积机理, 含蜡原油

Abstract: The components of the representative oil sample acquired from Unity 21 Well in Sudan were analyzed.The cloud point of wax was tested, and the wax deposition rate was measured with the automatic high-pressure wax deposition flow loop developed by the Research Institute of Petroleum Exploration and Development in cooperation with TEXACO of U.S.A.In order to simulate the production conditions, the cooling procedure was used to study the effects of the flow rate, oil temperature and ambient temperature on the wax deposition. The temperature in the cooling procedure ranges from that higher than the cloud point to lower one. The increase of flow rate resulted in a lower wax deposition rate. The experimental data were scaled up for waxy crude production line with a semi-empirecal scale-up wax deposition model. The wax deposition mechanism was described with the molecular diffusion and shear effects. The critical wax tension was used as a scalar. The wax deposition profiles along the production lines in the Unity 21 Well were predicted. The modeling results show that some factors have some impacts on the wax deposition profiles such as oil production rate and production time. No wax deposit in production line when the production rate is high enough. When the oil production rate is low, wax might deposit in the production line, and some wax-control techniques should be applied.

Key words: wax deposition, critical wax tension, simulation, production status, well bore, wax deposition mechanism, waxy crude