摘要
本文对油气藏原始含油气饱和度形成条件进行了研究,认为油气聚集的驱动压力在油气聚集中起到关键性作用,在孔隙结构特征相似的油气藏内,当驱动压力相同时,束缚水饱和度的变化取决于油层物性的变化;在物性相同时束缚水饱和度的变化取决于驱动压力的变化;在孔隙结构特征不相似的油气藏内,当储层物性、驱动压力相同时,束缚水饱和度的变化取决于孔隙结构中的微毛细管孔隙体积的变化(孔道半径小于1.0μm)。各种影响因素互补的最终结果,导致油气藏原始含油气饱和度,在油气藏顶部高于边部,气层高于油层。据此绘制出油层、气层的束缚水饱和度与孔隙度、渗透率、驱动压力三者乘积值的统一关系图版。此类图版适用于解释任意油气藏中不同位置上的饱和度。
This paper studies the establishment of initial hydrocarbon saturation in a sandstone reservoir and demonstrates that the pressure of hydrocarbon trap derived from the height of hydrocarbon column and fluid density difference plays a key role in hydrocarbon accumulation. In light of this idea, the oil saturation of various sandstone reservoirs was studied on the basis of analysis data of oil-based mud pressure coring, and some conclusions are drawn. For resevoirs with similar pore structure, if the displacement pressure is the same, the irreducible water saturation (Swi) depends on petrophysical properties of the reservoir rock. If the petrophysical properties are the same, SWi depends on displacement pressure. For reservoirs with different pore structure but with the same petrophysical properties and the same displacement pressure, SWj is governed by the pore volume of micro capillaries throat radius less than 1.0 μm in the pore structure. The Swi is governed at any point in a reservoir is the result of all the factors related. Accordingly, some unified charts showing the reationships between Swi and the product of porosity, permeability and displacement pressure have been made for both oil reservir and gas reservoir.
出处
《石油大学学报（自然科学版）》
CSCD
1990年第3期9-16,共8页
Journal of the University of Petroleum,China(Edition of Natural Science)
关键词
砂岩
油气藏
油气饱和度
Sandstone reservoir
Hydrocarbon saturation
Pressure
Core analysis
Pore structure
Charts
