【摘要】 重力流成因致密砂岩储层非均质性强、孔隙结构复杂，储层物性受成岩作用影响大，整体致密背景下成岩相分布控制优质储层的发育。综合利用岩心、铸体薄片、扫描电镜和测井数据，采用随机森林算法，研究鄂尔多斯盆地合水南地区长7段储层成岩相类型、识别及分布。结果表明：合水南地区长7段储层是重力流沉积致密砂岩储层，后期成岩过程中遭受强烈压实、胶结作用，导致储层致密，整体表现为超低孔—超低渗的特征；根据面孔率、溶蚀孔面孔率及成岩作用强度，定量划分4种成岩相，分别为压实致密相(Ⅰ类)、强胶结晶间微孔相(Ⅱ类)、复合孔相(Ⅲ类)及易溶组分溶蚀相(Ⅳ类),并以划分的成岩相及测井曲线为样本训练随机森林模型，优选DEN、GR、AC、RT、SP五条测井曲线识别成岩相，成岩相识别精度达85.4%;成岩相带分布整体沿物源方向(SW—NE向)呈条带状分布，易溶组分溶蚀相(Ⅳ类)和复合孔相(Ⅲ类)含油性好，是研究区优质储层相带。该结果为致密砂岩油高效开发提供指导。更多还原

【Abstract】 Tight sandstone reservoirs caused by gravity flow have strong heterogeneity and complex pore structure.The reservoir property is greatly affected by diagenesis.Diagenetic facies distribution restricted optimum reservoir development under the background of the tight sandstone.Based on previous research,this article comprehensively utilizes rock cores,cast thin sections,scanning electron microscopy,logging data,and random forest algorithm,to carry out diagenetic facies division,identification,and distribution prediction of the Chang 7 reservoir in Heshuinan(HSN) Area.The research has shown that:Chang 7 reservoir in Heshuinan Area is gravity flow sedimentation tight sandstone reservoir.During the later diagenetic process due to sufferred from strong compaction and cementation,which causing reservoir densification.According the face rate and face rate of dissolved pores and strength of diagenesis,the diagenetic facies can be divided into four types:tight compaction facies,strongly cementation intercrystalline micropore facies,composite pore facies and soluble component dissolution facies.Train a random forest model using partitioned lithofacies and logging curves as samples.And selecting five logging curves(DEN,GR,AC,RT,SP) to identify diagenetic facies.The accuracy of identifying diagenetic facies is as high as 85.4%.The distribution of diagenetic facies is generally in a strip like pattern along the source direction(SW-NE).The composite pore facies and soluble component dissolution facies have good oil content and are high-quality reservoir facies in the study area.It has clarified the distribution characteristics of diagentic phase in Heshuinan Area.This achievement has guiding significance for the efficient development of tight sandstone oil.更多还原