致密油不同于常规油藏上油下水、油水分界较明显,其含油饱和度一般随孔隙度增高而增大,同时离烃源岩越近含油饱和度也越高。因此,含油厚度不能简单地用油层顶到油水界面高度来表示,同时还要考虑裂缝对含油饱和度的影响。根据致密油的主要充注动力为生烃增压和毛细管压力差的特点，结合裂缝影响因素,应用渗流理论原理,建立了石油从烃源层直接渗入到致密储层深度的计算公式,应用加权平均方法计算致密油含油厚度。以中国石油3口井为例,计算各井致密储层的含油厚度,以此判断其含油情况,实践效果较好,为大面积致密油含油厚度评价提供了依据。

The tight oil is different from the conventional reservoir, and the boundary between oil and water is obvious.Generally, the oil saturation increases with the increase of porosity, and the closer to the source rock, the higher the oil saturation.Therefore, the oil-bearing thickness cannot be simply expressed as the height from the top of the oil layer to the oil-water interface,and the influence of fractures on oil-bearing saturation should also be considered.In this paper, according to the characteristics of the main filling power of tight oil to increase pressure for hydrocarbon and capillary pressure difference, combined with the factors affecting fractures, and by applying the principle of seepage theory, a calculation formula for the direct infiltration of oil from hydrocarbon source to the depth of tight reservoir is established,and the oil thickness of tight oil is calculated by weighted average method.Taking 3 wells of CNPC as an example, the oil content thickness of tight reservoirs in each well is calculated to judge the oil content.The practical effect is good, which provides a basis for the evaluation of oil content thickness of tight oil in a large area.