核磁共振测井在致密油孔隙结构及储层综合评价中的应用

Application of NMR Data to Evaluation of the Pore Structure and Reservoir with Tight Oil

准噶尔盆地准东北部平地泉组致密油储层具有岩性复杂、低孔隙度低渗透率、非均质性极强、孔隙结构复杂的特点。为节省取心成本,采用分段非线性刻度转换方法,由核磁共振测井T2谱构建伪毛细管压力曲线及相关关系法连续计算孔隙结构参数,综合利用储层宏观尺度和微观尺度的定量化孔隙结构参数与试油资料建立基于产能的储层类型判别标准,将储层分为3类,很好地指导了储层压裂改造选层和压裂方案设计及产能预测。建立精细核磁共振毛细管压力转换模型,结合产能建立适合致密油储层评价标准。

The tight oil reservoir of the Pingdiquan group in the Junggar basin northeast has complex lithology, low porosity, low permeability, strong heterogeneity and complicated pore structure. To lower coring cost, the pore structure parameters are calculated by two methods, one is the conversion method of section nonlinear scale construction of pseudo capillary pressure curve by NMR T2 spectrum, the other is correlation method. Quantified pore structure parameter and oil test data of macro-reservoir and micro-reservoir are used to set up productivity-based reservoir types evaluation standard; based on this standard, the reservoir is classified into 3 types, thus, bettering the reservoir fracturing improvement, zone selection, fracturing plan and productivity forecast. The fine NMR capillary pressure conversion model is given, and combined with productivity the suitable tight oil reservoir evaluation standard is also established.