致密砂岩气藏核磁共振测井与常规测井的孔与渗透模型关系

为建立良好的测井物性解释模型,以更准确地评价塔巴庙地区上古生界盒3段致密砂岩气藏产能,对比了14块岩样的核磁孔隙度与其岩心孔隙度,发现它们有线性相关性;对比核磁渗透率与岩心渗透率,也获相同结果.这表明核磁孔渗与常规孔渗线性相关.以此为依据,以核磁共振测井的孔渗为桥梁,以常规测井数据为基础,建立了常规测井的孔、渗计算模型.所建模型既避免了取心位置与常规测井之间深度的不一致性,又不会存在因岩心数据的不连续而带来的岩心孔渗模型计算值应有的误差,所以它更适合于盒3段储层孔渗的评价.

Relationship of pore and permeability models between NMR log and conventional log in tight sandstone gas reservoir

For establishing a good log petrophysical model and evaluating productivity of tight sandstone gas reservoir in Tabamiao area of Ordos basin accurately, NMR porosity data of Section 3 of the wells were compared with the core porosity values for 14 cores. A linear relationship was observed. A comparison between the NMR permeability and core permeability gave similar result. This indicates a linear relationship between the porosity and permeability from NMR log and conventional log. Using the NMR porosity and permeability and conventional log data, accurate conventional log porosity model and permeability model were established. As NMR log avoids the non-parallelism of depths with conventional log and the pore-permeability model established by incontinuous core data causes no error, the new models are more appropriate for the porosity and permeability estimation of the gas formation.