双河油田438块构造油藏油水界面差异分布的主导因素

THE MECHANISM OF DIFFERENTIAL DISTRIBUTION OF THE WATER OIL CONTACT IN BLOCK 438 OF SHUANGHE OILFIELD

双河油田位于南襄盆地泌阳凹陷西南部,为一轴向为SE—NW的鼻状构造倾伏端,其中438块核三段Ⅲ11的A油区是砂岩储层的鼻状构造油藏。在油田开发过程中发现该油藏油水界面深度不一,因此,从油气成藏力学的角度,结合研究区的储层研究资料,对油水界面差异分布的成因机理进行了深入研究。研究结果表明,油气藏油水界面的差异分布主要受控于储层物性、地层倾角及原油密度等因素,而双河油田438块核三段Ⅲ11的A油区各区域由于地层倾角及油水密度差相同,油柱高度即油水界面差异性分布主要受物性因素控制。

The study of differential distribution of WOC is meaningful for understanding the geologic features of the reservoir,evaluating accurately the reserves of an oilfield and improving the oilfield development.The Shuanghe Oilfield is located in the Southwest of the Biyang Depression of the Nanxiang Basin,at the plunging part of a southeast-northwest axis nose structure.The oildom A of the Block 438 is a nose structure reservoir in the monolayer of H3Ⅲ11.It is found during the oil field development that the WOC depth is different in different places.So far the phenomenon has not been well studied.We studied in this paper the mechanism of the differential distribution of WOC from the perspective of oil pool-forming dynamics with reservoir research data.According to the dynamics of oil and water differentiation,the distribution of WOC is controlled by physical properties of reservoir,dip of strata and the density of crude oil.The physical properties of reservoir,dip of strata remain same in the region.Therefore,the difference of oil column height,or the differential distribution of WOC,is mainly affected by physical properties of the reservoir.