原油沥青质絮凝初始点的测定——以渤海绥中36-l油田稠油为例

DETERMINING THE ONSET OF ASPHALTENES FLOCCULATION IN CRUDE OIL—A CASE OF SZ36-1 OILFIELD

沥青质在原油中的稳定性主要取决于原油对沥青质的溶解能力。当溶解能力下降到某一临界值后，沥青质就会从原油中絮凝析出，该临界值即为沥青质絮凝初始点。采用透光率法、粘度法和显微镜法对常压下渤海绥中36—1油田稠油沥青质的絮凝初始点进行了测定。结果表明，粘度法和显微镜法测定结果比较准确、合理，而透光率法因受原油色深和分光光度计光源条件的限制而使沥青质絮凝初始点滞后；在给定压力下，温度升高会使原油沥青质素凝初始点提前。

The stability of asphaltenes in crude oil is mainly dependent on the asphaltenes solubility of crude oil. Once the solubility decreases to a critical point, the asphaltenes will flocculate from crude oil and the point can be referred to as the onset of flocculation. In this study, the onset of asphaltenes flocculation in the heavy oil from SZ36?1 oilfield, Bohai Bay, was determined using spectrophotometry, capillary viscometry and microscopy separately. The results determined with the viscometric and microscopic methods seem to be more accurate and reasonable, and the spectrophotometry may lead to a delay in the onset of asphaltene flocculation due to the limits of crude oil colour and light source. In addition, as the temperature increases, a pre_flocculation of asphaltenes will occur in crude oil.