薄层稠油油藏径向钻孔热采开发数值模拟

 以径向钻孔技术应用于薄层稠油油藏热采开发为目标,采用基于等效渗流连续介质原理及局部网格加密技术的数值模拟方法,在较高的拟合精度基础上,研究了径向孔长度、径向孔平面夹角、径向孔数量等因素对薄层稠油油藏蒸汽吞吐采油产量的影响。结果表明,径向孔能够增加蒸汽波及范围和泄压面积,有效提升采油产量;径向孔长度增加时采油产量逐渐增加但增幅逐渐减小,径向孔长度的最优范围为100~120 m;储层同一平面分布的径向孔,孔间夹角较大时相互干扰作用较弱,增产效果较好;同一平面分布的径向孔数量增加时,径向孔之间的夹角逐渐减小,相互干扰作用逐渐增强,产量增幅逐渐变小,当以平均夹角分布4条径向孔时可获得明显的增产效果。

Numerical simulation of radial drilling in thermal recovery and development of thin heavy oil reservoirs

To apply the radial drilling technique to thermal recovery and development of thin heavy oil reservoirs, a simulation study based on the equivalent continuum principle and local grid refinement technology is carried out. On the basis of historic matching of a higher fitting precision, the influences of the factors of length, plane angle and the quantity of the radial hole on oil production are studied. The results indicate the followings. The radial holes can increase the scope of steam and the area of pressure release and can enhance the production effectively; the oil production gradually increases with the increase of the radial hole length, but the increase rate decreases, with the optimal range of length of the radial hole being 100 to 120 m; a large angle of the distribution of the radial holes in the same plane in the reservoir has weak interference and production grows well; when the number of the radial holes in the same plane increases and the angle between the radial holes gradually decreases, mutual interference gradually strengthens and the output growth gradually declines; and the average angle distribution of four radial holes can obtain an obvious effect on oil production.