滨里海盆地M油藏属于稠油油藏，目的层埋深较浅，储层较为疏松。油田开发主要以热采为主，水窜容易造成油藏水淹，且新井初期含水率较高，为此开展水淹层测井评价对于制定科学合理开发调整方案，提高油田开发效率具有重要的意义。通过J函数建模求取原始含油饱和度来评价水淹层，基于M油藏取芯井的岩心资料，结合粒度分析、铸体薄片、扫描电镜、物性分析及压汞实验等方法，通过毛管压力曲线对目的层J函数进行建模，计算原始含油饱和度，对比原始含油饱和度与目前含油饱和度评价水淹层。结合生产测试结论，证明J函数方法在水淹层评价方面效果较好，这种方法对于构造油藏水淹层评价具有重要的参考意义。

The M reservoir in the coastal Caspian Depression belongs to heavy oil reservoir, with shallow burial depth of target layer and weak reservoir cementation. The main method of oilfield development is thermal recovery, and water channeling can easily cause reservoir flooding, and the initial water content of new wells is high. Therefore, conducting logging evaluation of water flooded layers is of great significance for formulating scientific and reasonable development adjustment plans and improving oilfield development efficiency. To evaluate the water flooded layer by calculating the original oil saturation through J function modeling. Based on the core data of M reservoir, combined with Particle size analysis, casting thin section, scanning electron microscope, physical property analysis and mercury injection test, the J function of the target layer was modeled through capillary pressure curve, and the original oil saturation was calculated. The water flooded layer was evaluated by comparing the difference between the original oil saturation and the current oil saturation. Based on production testing results, it is proved that the J-function method is effective in evaluating water flooded layers, and this method has important reference significance for evaluating water flooded layers in structural oil reservoirs.