三相相对渗透率曲线实验测定

通过岩心和薄片观察、流体压力特征和地球化学指标分析,探讨三塘湖盆地马朗凹陷芦草沟组泥页岩系统地层超压形成的原因以及页岩油富集机理.研究表明,芦草沟组页岩油是烃源岩在低成熟—成熟早期演化阶段生成的液态烃,具有高密度、高黏度的物性特点；烃源岩厚度大,渗透率低,造成流体启动阻力增大,油气不具备大规模向外排运的条件而滞留在源岩层中,其为超压形成的主要原因.芦草沟组泥页岩生烃潜力大,源内储集空间发育,是其生成的油气滞留其中的基础；生烃造成的地层压力不足以突破油气运移的阻力,是页岩油富集的直接原因.页岩油的富集程度受控于不同岩相在不同演化阶段的生烃、储烃能力.

Measurement of three-phase relative permeabilities

Three-phase relative permeabilities of water-wet and oil-wet outcrops with two saturating histories (DDI and IID) are investigated by steady physical simulation experiments. CT Dual Energy Simultaneous Scanning (DESS) method was introduced to measure three-phase saturations accurately, which can eliminate the end effect. The relative permeability of each phase at a given saturation is calculated by Darcy law. The experiment results clearly show that for water-wet cores, the isoperms of water are straight lines, which means that the relative permeability of water depends on water saturation only. The isoperms of oil are curves concave towards 100% oil saturation point, and the isoperms of gas are curves convex towards 100% gas saturation point, which means that the three-phase relative permeability of oil and gas depend on all the three phase saturations. For oil-wet cores, all the isoperms of water, oil and gas are curves convex towards their 100% saturation, which means that the three phase relative permeability of water, oil and gas depend on all the three phase saturations. In addition, the isoperms of wetting phase are similar for the two saturation histories, while those of non-wetting phase are quite different. Though the isoperms are the same in shape, they are different in values and positions