非均质性砂砾岩稠油油藏三维地质建模研究——以风城油田重18井区侏罗系八道湾组油藏为例

3D geological modeling for heterogeneous glutenite reservoir with viscous oil:a case of Jurassic Badaowan Formation reservoir in Zhong 18 well block in Fengcheng Oilfield

风城油田重18井区八道湾组油藏为一典型非均质性较强的砂砾岩稠油油藏,目前,无论是基于单一沉积微相建模技术,还是基于单一岩石相建模技术,均无法在细致刻画储层内部各类岩石空间分布的同时,又保证其砂体展布符合地质规律认识,存在一定的局限性。笔者以风城油田重18井区八道湾组油藏为例,利用实际测井、岩心及物性分析资料,以单井沉积微相与岩石相划分为基础,建立能够表征沉积微相及岩石相分布的联合相类型,并以此为基础,通过对各相变差函数的调节,建立联合相地质模型。该相模型具有既符合沉积微相地质认识,又能表征岩石相空间变化的优势,对非均质性较强的储层刻画效果较好。在此基础上利用序贯高斯算法,建立储层的属性模型,最后进行地质储量拟合。通过模型的质量检验,验证模型可靠后,进而验证该方法能够用于非均质性砂砾岩特殊稠油油藏的三维地质建模,并且模型能够为水平井井轨迹设计提供依据,为后期油藏动态管理以及稠油注气扩散过程的数值模拟奠定基础。

The Badaowan reservoir in Zhong 18 well block,Fengcheng Oilfield,is a typical heterogeneous glutenite reservoir with viscous oil. Neither the 3D microface model nor the 3D rock face model can describe the distribution of lithofacies in detail,and coincide with the geological cognition simultaneously due to their limitations. Integrating of microfacies and lithofacies,the joint facies was established,which can characterize the distribution of sedimentary microfacies and lithofacies,braided river-gravel face,channel bar-medium-fine sandstone face,floodplain-mudstone face and swamp-coal face. Based on those facies,the author adjusted the variation function,and used the sequential indicator simulation algorithm to establish the 3D joint facies model with a 2D phase plane as constraint conditions. This model not only conformed to the geology cognition of the deposition microfacies,but also characterized the transverse and longitudinal changes of lithofacies. And then a property model of reservoir was established by the sequential Gauss algorithm,which was used to fit geological reserves. The quality testing verified the reliability of the method which be used to create a 3D model for heterogeneous glutenite reservoir with viscous oil. The 3D model can provide a basis for the trajectory design of horizontal well and the dynamic numerical simulation of the reservoir in the future.