萨中地区特高密井网下点坝构型建模与应用

Configuration modeling and practical application of point bar based on dense well pattern in Sazhong area

为解决点坝内部储层强非均质性及剩余油挖潜等难题,本文基于萨中开发区PI2a单元特密井网资料,结合现代沉积与露头,综合多方法定量求取点坝构型参数,进而建立点坝三维构型模式.由此,创新地提出一种依据夹层的平面轨迹,利用空间平移,以线控面,在构型参数约束下定量实现侧积夹层三维构型建模的方法,最大限度恢复地质构造,确定点坝内部非均质性与剩余油规律.研究表明：靶区内共识别出倾向为方位角320°、倾角范围在3.5°-13.1°、平均间距9.5 m、平均延伸25 m的夹层15个,夹层剖面为上缓中陡下缓的凹面,平面为新月形;侧积体剖面上表现为斜列式侧积叠加的三维空间结构特征.受夹层影响,点坝内部具有极强的非均质性,剩余油分布主要呈现＂下部稀缺、中部较为富集、顶部极为富集＂的规律,据此提出于点坝中上部钻穿水平井,提高剩余油挖潜效率的建议.

To solve the problem of the anisotropism and tapping of residual oil in point bar,this paper,based on the dense well pattern data of PI2 a unit of Putaohua oil layer in Sazhong development area of Daqing oilfield,combined with the model of modern sediments and ancient outcrop,determining the configuration parameters of point bar quantitatively by many methods,therefore,establishing the three-dimensional configuration model of point bar lateral accretion interbeds which located in the meandering channel. On the basis of this model,this paper proposed a three-dimensional modeling method which based on the path of interbeds on PI2 a layer,using the principle of space translation to finish the threedimensional configuration model of point bar lateral accretion interbeds under the control of configuration parameters,analyzing the anisotropism and residual oils in point bar roundly. The result shows that there are fifteen interbeds in study area,and its azimuth of tendency are 320°,the range of dip angle is 3. 5° to 13. 1°;besides,the interval of each interbeds are 9. 5 meters,and the stretch of every interbed are 25 meters. The profile of interbeds presents concave surface which is slow,steep,slow from the bottom to surface,and the plane of interbeds presents crescent. The lateral accretion interbeds are in crescent arrangement on the plane,and in imbricate and echelon distribution on the profile. Under the influence of interbeds,there are extremely anisotropism in point bar,and it＇s residual oil mainly present by the way of＂the scarcity in lower parts,better in middle parts,the enrichment in upper parts＂,therefore,proposed an advice that drilling horizontal wells in the upper part of the point bar to improve the efficiency of tapping the residual oil in point bar.