鄂尔多斯盆地铁边城地区长2油层组剩余油模拟

为了实现油田增储上产及老井挖潜的目标,提升剩余油资源开发潜力,通过岩心、薄片、电镜、物性、模拟方法系统的研究了鄂尔多斯盆地西北部姬塬油田铁边城地区长2段主力油层的剩余油分布特征。研究显示,长2₁^3-2和长2₁^3-3小层为主力产油层,平均厚度分别为12.2 m及11.1 m。目的层砂岩储层的孔隙度通常介于12%～18%,渗透率则通常低于8 mD。根据相控原则,建立了主力产层的物理属性模型及流体模型;进而,开展了剩余油分布数值模拟研究。通过基于实测产水及产油量约束的历史生产曲线拟合,获得了剩余油的纵横向分布结果。研究显示,剩余油分布受砂体边界、物性差异及注采关系的影响。剩余油整体上成片分布;但是,受油藏物性差异的影响,注水多呈不均匀受效,因而造成局部剩余油富集。剩余油主要分布在砂体边界处,这些区域无井网控制,因而水驱程度低,剩余油分布较多。受长期注采的影响,井间会形成高渗区,这些其余类似高速通道,会发生快速水淹,其周边则形成剩余油滞留区。可见,剩余油富集明显受微相、物性、注水及井网因素的控制。

Simulation of remaining oil in Chang 2 Member in Tiebiancheng area, Ordos Basin

How to effectively predict and develop the remaining oil resources is an important work to increase the oil field storage and production and explore the potential of old Wells. In this paper,taking Chang 2 Member of Tiebiancheng area,Jiyuan Oilfield,northwestern Ordos Basin as an example,the remaining oil distribution characteristics of the main reservoir were systematically studied by using core,thin section,electron microscope,physical properties and numerical simulation methods. The study shows that the Chang 213-2 and Chang 213-3 layers are the main oil-producing formations with average thicknesses of 12.2m and 11.1m,respectively. The main oil-producing layers have the porosity of 12%-18% and permeability of less than 8mD. According to the principle of phase control,the physical property model and fluid model of the main production zone are established. Furthermore, the reservoir numerical simulation was carried out by using ECLIPSE Software. The historical fitting results show that all the production indexes are in good agreement with the measured data,and the simulation results are reliable. The numerical simulation results show that the remaining oil distribution is affected by sand body boundary, physical property difference and injection-production relationship. However,due to the difference of reservoir properties,the effect of water injection is not uniform,resulting in local remaining oil enrichment. The remaining oil is mainly distributed at the boundary of the sand body. There is no well pattern control in these areas,so the degree of water flooding is low and the remaining oil is distributed more. As for the areas on both sides of the high permeability zone between injection and production Wells,the oil well is flooded quickly and the oil well production decreases rapidly because the injected water breaks out along the high permeability zone between injection and production Wells. At the same time,due to the small affected area and uneven water flooding,the areas on both sides of the hyperpermeability zone did not get effective water flooding,forming the remaining oil-rich area.