为了了解底水油藏水平井开发过程中水脊发展规律,根据底水油藏水平井开采机理,建立了其开采过程的渗流数学模型,采用方程分析方法推导出了底水油藏水平井采油物理模拟的相似准则数群,根据相似准则研制底水油藏水平井开发物理模拟装置,利用该实验装置分别研究了均质地层和具有隔夹层底水油藏的水脊上升形态与水平井开发动态。结果表明:在均质条件下,水平井见水位置在中部;当水平井附近具有隔夹层时,水平井含水率上升缓慢,并且随着隔夹层展布的增大,底水受到的抑制作用愈发明显,水平井见水时间延迟;对实际底水油藏水平井生产动态进行分析表明,隔夹层对开发效果的影响与物理实验结果相同。研究表明,可以充分利用隔夹层对底水的遮挡作用,尽量使夹层靠近水平井,并且应适当增大隔夹层的展布,提高水平井开采效果。
To identify water cresting during the development of bottom water reservoir by horizontal wells, a mathematical seepage model was established on the basis of oil recovery mechanism of such reser- voir with horizontal well, the scaling groups for physical analog were derived with equation analysis, and the relevant physical simulator was developed based on similarity criteria. The rising pattern of water crest and the development performance of horizontal well have been studied by experimental device for homoge- nous formations and bottom water reservoirs with interlayer. The result shows that, in case of homogenous formation, water breakthrough occurs in the middle section; when interlayers are shown near the horizontal well,the water cut rises slowly,and as the extension of these interlayers, the bottom water is increasingly restricted and the water breakthrough is delayed. In addition, the actual performance of horizontal well in bottom water reservoir was analyzed, showing that the interlayers have the same impact on development re- sults as those given in the physical experiment. Therefore, the shelter of interlayers upon bottom water should be fully utilized, strive to have the horizontal hole closed to interlayers and choose the proper thickness of interlayers, so as to improve the efficiency of recovery in horizontal wells.