花土沟油田N_2 2储层沉积微相及含油性研究

Study on Sedimentary Microfacies of the N_2~2 Reservoir and Its Implications for Oil in the Huatugou Oilfield

上油砂山组N22储层段是柴达木盆地西部花土沟油田最上部的一个含油层段,目前正进行试采开发。了解其沉积微相类型及特征、沉积微相平面与纵向展布,探讨沉积微相与含油性的关系,对油田进一步勘探开发将具有重要意义。通过对花土沟油田N22储层岩心、粒度、岩性和测井等的综合分析,揭示出N22储层段为三角洲平原亚相沉积,并进一步细分为分支河道、河漫滩、河泛平原等3种沉积微相,进而开展平面及纵向展布特征研究;同时,依据取心含油显示及试油、试采资料,分析了3种沉积微相与含油性的关系,指出N22储层段分支河道及河漫滩沉积微相具有一定的工业油流,是下一步勘探的主要目标。

Huatugou oilfield is located in the western Qaidam basin,and N22 reservoir is the research area in the upper part of an oil bearing intervals,the current trial mining development.Therefore,understanding the types and characteristics of the sedimentary microfacies,sedimentary microfacies plane,vertical distribution,exploration of the relationship between the sedimentary microfacies and oiliness has guiding significance to the exploration and development.Comprehensive analyses of the core,grain size,lithology,well logging reveal that the reservoir section of the delta plain subfacies is subdivided into 3 types of sedimentary microfacies including distributary channel,floodplain and river flood plain.Analysis of sedimentary microfacies of plane and longitudinal distribution has been performed.Based on the coring oily and oil testing,test mining information on the foundation,relationship between the three sedimentary microfacies and oil-bearing property are explored.Our results show that reservoir branch channel and floodplain depositional microfacies have certain industrial oil flow,which is the main objective for further exploration.