断背斜油藏油水界面的差异分布及成因探讨

Discussion on the Differential Distribution of WOC and its Mechanism in the Faulted Anticline Reservoir

利用取芯资料及密井网测井资料,在等时地层格架的基础上,精细描述了胜坨油田胜利村断背斜油藏沙二段81层储层特征及油水分布规律,利用非均质油藏成藏动力与成藏阻力之间的力学平衡关系,探讨了断背斜油藏中油水界面差异分布的成因机理。研究表明,断背斜油藏同一沉积单元中,各含油断块在油柱高度和油水界面深度方面存在较大差异,同一含油断块内部的油水界面与构造线并不完全平行。储层物性更差、构造更平缓、原油密度更大的断块和区域具有更高的油柱高度,从而导致了油水界面的差异分布。在实际油藏中,油柱高度存在的断块间差异和断块内差异是非均质储层油水界面分布的普遍特点,但具体油水分布状态要受储层非均质性、构造趋势、原油性质等因素的叠加影响。

Based on the isochronous formation frame, the reservoir characteristics and oil ＆ water distribution pattern of Es2 （81 ） sand unit in Shenglicun faulted anticline of Shengtuo Oilfield are described by using of core data and close spacing log information. With the mechanical balance between the driving force and resisting force of petroleum accumulation, the mechanism of the differential distribution of WOC in faulted anticline reservoir is elaborated. The result shows that the oil column height and WOC depth in the same sand unit but different block are inconsistent in the faulted anticline reservoir, and the WOC in the same block is not parallel with the structural contour. The block and area with poorer physical property, smaller strata dip and higher oil density can hold higher oil column height, which causes the differential distribution of WOC in planar shape. In the actual reservoir, the regional difference ofoil column height between blocks and in same block is a basic feature, and the situation of WOC is controlled by reservoir heterogeneity, structural attitude and oil density comprehensively.