EFFECT OF WAX CRYSTAL MORPHOLOGY ON THE POUR POINT DECLINE OF CRUDE OIL

The variety of wax crystal morphology under different condition was observed by micropolariscope and the wax crystal structure and distribution and grow regulation in crystallizing process were studied.The carbon number and distribution in the wax-containing simulation oils prepared by 52~#,62~#,80~# wax were analyzed by gas chromatograph.The relationship of pour point with the wax content was gained.The effect of asphaltene,resin and pour point depressant(PPD) with high molecular mass on the pour point and viscosity decline of the wax containing simulation oil was discovered,which provided the theory basis for effectively improving the oil flow properties.The result of experiments showed that the wax crystal morphology and dissolubility of wax in the oil and effect of pour point decline by PPD were closely related to the carbon number and distribution of wax in the wax-containing simulation oil.The ideal effect of pour point decline was got only when PPD molecule structure well matched with the wax structure in the oil.The critical wax content of wax-containing simulation oil during pour point decline confirmed by the experiments reached to about 40%(mass fraction) over which the range of pour point decline would decrease greatly.