Research On The Model Of Wax Deposition

Problems originated from wax deposition are important factors which greatly affect waxy crude pipelining′s operation safely, economically and efficiently, studying the wax-deposition law of waxy crude pipeline has great engineering importance and learning value. By exploring the deposition and the effective quality of wax crystals of a wide range of crude oil and laws of other effective factors, a wax deposition dynamic model including the effective quality of wax crystals is founded and validated. The model can predict the distribution law of the thickness of the wax deposition along the actual pipeline and provide the basis for the establishment of the reasonable pigging program and the optimal operation of pipeline.In this paper, the relationship between the effective quality of wax crystals and the flow conditions and between the effective quality of wax crystals and the pipeline (operating) parameter are studied to assure the various factors impacting the wax deposition rate. The wax deposition dynamic model is established by analyzing and evaluating each factor that affects deposition rate and wax deposition by the application of multiple linear stepwise regression and endless enumeration based on the data of the existing 9 kinds of crude oil and 123 groups of wax deposition. The model in this paper predicts the law of the wax deposition of the different pigging periods in zhong-yin pipeline and compared with the data of the local wax deposition. The result shows that the model can be used for the prediction of the distributing law of the wax deposition in wax crude oil pipeline. As an example of the model, the distribution in the 7 pigging periods of the wax deposition along zhong-yin is predicted between January and April in 2004.