蒙古国查干油田基本石油地质特征

Basic petroleum geolog characters of Tsagaan Els oil field in Mongolia

通过对钻井、录井、岩心化验、试油等资料的研究,结合区域勘探成果,分析了查干油田的基本石油地质特征。研究表明,下宗巴音组下段发育200m左右的油泥岩和暗色泥岩,有机质类型为Ⅱ1型,镜质体反射率平均值为0.7%,生烃指标好,评价为优质烃源岩;查干油田处于"凹中隆"上,其西、北、东三面被生油洼陷环绕,成为捕捉油气最有利的场所。查干组和下宗巴音组发育扇三角洲前缘水下分流河道和席状砂微相,查1和查27断块油藏储层物性好,为中孔中渗透储层;查14断块油藏为中孔低渗透储层。通过成藏特征分析认为,中央断裂背斜带因近油源、纵向上输导条件好而成为油气聚集的有利构造带,并且与良好的储集相带相匹配,为查干油田的形成创造了条件。

Tsagaan Els oil field is the second oil field that was found in Mongolia in the early time.In recently years,the exploration opera-tions are successful with geology reserves up to 1 234.56× 104 tons.Herein,the well drilling data,well logging information,co-ring analysis and oil testing etc are thoroughly studied.Moreover,area achievements are referenced to analyze the basic petroleum geology features of Tsagaan Els oil field.According to the study above,there are 200 meters thickness of oil shale & dark shale in the lower section of Low Zuunbayan formation.The type of organic matter is Ⅱ1,and the index of hydrocarbon generation is fa-vorable.So.it is excellent source rock.The Tsagaan Els oil field is located on the central anticline fault belt.and surrounded west-ward,northward and eastward by the oil generation sag.which all have contributed the study area to be the most proximal and fa-vorable place Trapping the oil and gas.The sedimentary microfacies are fan delta front submersed channel & sheet sandstone in the target stratum of Lower zuunbayan and Tsagaan Els formation.The physical properties of TE1 & TE27 reservoir are good.It is a medium porosity and permeability reservoir.TE14 is medium porosity and low permeability reservoir.After the analysis of reservoiring characters.the central anticline fault belt is favorable for oil accumulation because it is proximal to the oil source and has good lateral migration conditions.In addition,the structure belt and reservoir facies zone are well matched.All of which above have created the conditions for the occurrence of Tsagaan Els oil field.