【摘要】 准噶尔盆地低电阻率油层发育,高束缚水饱和度是低电阻率油层的主要成因之一;低电阻率油层束缚水饱和度的准确确定是明确油层低电阻率成因并确定含油饱和度的关键。常用束缚水饱和度确定方法结果差异较大,束缚水饱和度的准确确定存在困难。以准噶尔盆地阜东斜坡区头屯河组储层为例,实验对比了核磁共振分析法、压汞毛细管压力曲线法、半渗透隔板毛细管压力曲线法所确定的束缚水饱和度。岩心实验结果对比表明,核磁共振分析法、压汞毛细管压力曲线法确定的束缚水饱和度均小于半渗透隔板法确定的束缚水饱和度。核磁共振分析法中实验所用离心力远大于成藏时油运移的驱替力,造成部分束缚水被离心出来;压汞法在实验过程中,岩样中的黏土束缚水被驱替出来。这2种方法测量的束缚水饱和度均偏小。半渗透隔板法由于充分模拟了油气运移过程中非润湿相(油气)驱替润湿相(地层水)的过程,其中的黏土束缚水未被驱替,与油层实际情况相符,可用于验证另外2种方法的可靠性。更多还原

【Abstract】 Low-resistivity oil layers are well developed in Junggar Basin. High irreducible water saturation is one of the main causes for low-resistivity oil layers. How to accurately determine irreducible water saturation is the key to determine the origin of low-resistivity layers and oil saturation. Different methods commonly used provide different results, so that it is hard to determine accurate irreducible water saturation. Taking the Toutunhe Formation reservoir in the Fudong slope of Junggar Basin as an example, NMR, mercury intrusion and semi-permeable plate methods were compared through core experiments, and the results indicate that the irreducible water saturation determined by either NMR or mercury intrusion is less than that determined by semi-permeable plate method. During the NMR experiment, it was found that the centrifugal force was far greater than the displacement force for oil migration during the process of hydrocarbon accumulation, which resulted in the centrifugation of some irreducible water. During the mercury intrusion experiment, the irreducible water in the clay in the rock sample was displaced. Therefore, the irreducible water saturation measured by any of the two methods is smaller than the actual. The semi-permeable plate method fully simulated the process of non-wetting phase(oil and gas) displacing wetting phase(formation water) during oil and gas migration, and the irreducible water in clay was not displaced, which is consistent with the actual situation. The semi-permeable plate method can verify the reliability of the other two methods.更多还原