Abstract: 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 reservoir 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 homogenous 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 results 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.