基于密井网水下分流河道单砂体原型地质模型

在大庆萨尔图油田中区西部,应用多套加密井网构成的高密度开发井资料(平均井网密度275口/km~2),首次开展了基于密井网的大型浅水湖盆河流三角洲分流河道单砂体原型地质模型研究。通过从一维井孔、二维平面到三维地质体不同维度的水下分流河道单砂体精细表征,实现了水下分流河道井间砂体边界准确刻画;细划出4种水下分流河道单砂体成因类型,建立起平面网格步长20 m×20 m,纵向网格精细到0.1 m的高精度三维地质模型,量化了不同类型分流河道单砂体几何参数及不同岩性分布概率等单砂体内部构型参数。基于密井网的储层原型地质模型,深化了对浅水三角洲不同类型分流河道单砂体规模、井控程度以及剩余油潜力分布特征的认识,量化的模型参数对提高稀井网区储层预测与建模精度,指导高含水油田开发调整挖潜具有重要意义。

PROTOTYPE GEOLOGICAL MODEL FOR THE INDIVIDUAL SANDBODY OF THE UNDERWATER DISTRIBUTARY CHANNEL BASED ON THE DENSE WELL PATTERN

Based on the development well data of several sets of the high-density well pattern (with an average well spacing density being 275 wells/km2) in the Central West District of Daqing Saertu Oilfield,a prototype geological model research was conducted about the single sandbody of the large-size shallow-lake-basin river delta distributary channel.Through the fine characterization of the underwater distributary channel single sandbody from one dimensional hole,two-dimensional flat profile to three dimensional geologic body,the interwell sandbody boundaries were accurately described;Four types of underwater distributary channel single sand body genesis were divided in detail,three-dimensional high-precision geological model with the plane grid step 20 m× 20 m and the longitudinal fine grid to 0.1 m was established to quantify the internal framework parameters of the individual well such as differenttype distributary channel sandbody geometry parameters and different-lithology distribution probability and so forth.Based on the reservoir prototype geological model of the dense well pattern,the understandings were deepened for the different-type distributary channel sandbody size of the shallow-water delta,the degree of well control and the distribution characteristics of the remained oil potential,and moreover the model parameters were quantified.All the achievements possess a great significance for improving the reservoir prediction and modeling precisions of the loose well-pattern block and guiding the development adjustment and potential tapping of the high-watercut oilfield.