用数字化核磁共振测井成果建立孔隙度渗透率模型

Digitizing Diagram of NMR Log to Model Porosity/Permeability Calculated with Conventional Logs

发现DK3井14块岩样的核磁共振孔隙度与其岩心孔隙度具有很好的线性相关性,他们的渗透率也是如此;常规测井的孔隙度/渗透率与岩心孔隙度/渗透率也具有很好的线性相关性。于是就假设核磁共振孔隙度/渗透率与常规孔隙度/渗透率之间同样具有很好的线性相关性。据此,以校正后的核磁共振测井的孔隙度/渗透率资料为准,建立起了常规测井的孔隙度/渗透率计算模型。在没有核磁共振测井原始数据时,可通过数字化软件从核磁共振测井成果图读取有关数据。这样建立的测井物性解释数学模型,既避免了取心作业与测井作业之间的深度误差,又不存在因岩心数据的不连续而带来的岩心孔隙度/渗透率值的误差,使该模型适于更准确评价塔巴庙地区上古生界盒3段致密砂岩储层的孔隙度/渗透率。

It is discovered that there is nice linear correlation between the NMR porosities and core porosities in 14 cores from DK3 well, and so is their NMR permeabilities and core permeabilities, and that nice linear correlation of porosity/permeability also exists between the conventional logs and core data. So supposed is that there also might be same correlation between the porosity/permeability of NMR and conventional logs. Based on the assumption, a conventional logging porosity/permeability model is established according to corrected data of NMR porosity/permeability. While no original data of NMR log are provided, the data of NMR can be acquired from digitizing diagram of the NMR log. With the mathematic model of logging petrophysical property interpretation established in this way, there is neither the depth error between coring operation and logging operation, nor the porosity/permeability error caused by discretely coring, so that the model is more suitable to accurately estimate the porosity/permeability of upper Palaeozoic tight sandstone reservoir of He-3 zone in Tabamiao area of ordos basin.