玛湖地区低渗透致密砂砾岩储层渗透率模型研究及应用

Research and Application of Permeability Model of Low Permeability and Dense Sandy Conglomerate Reservoir in Mahu Area

准噶尔盆地三叠系百口泉组发育了大量的低渗透致密砂砾岩油层,储层岩石颗粒粒级分布范围较大,非均质性较强,孔隙度渗透率关系规律不明显,给储层的评价带来困难。为建立适合低渗透致密砂砾岩储层的渗透率模型,从储层岩性、孔隙类型及黏土含量等因素分析储层渗透率的变化规律。储层发育较好的细砾岩渗透率最好,次生孔隙类型渗透率比原生孔隙发育好,储层渗透率随着黏土含量的增加而降低。提出在分岩性的基础上结合测井数据建立渗透率关于孔隙度和黏土含量的计算模型,并对其进行实际应用,对比常规渗透率模型计算的测井渗透率和分岩性多元回归方法计算渗透率,发现后者计算效果较好,为后期储层精细评价提供可靠依据。

The Triassic Baikouquan Formation in the Junggar Basin has developed a large number of low-permeability dense sandstone conglomerate reservoirs. The reservoir has a large distribution range of particle size and strong heterogeneity,moreover,the relationship between porosity and permeability is not obvious.These characteristics make it difficult to evaluate the reservoir,especially the permeability.In order to establish a permeability model suitable for lowpermeability dense glutenite reservoirs,the change law of reservoir permeability was analyzed based on the reservoir lithology,pore type and clay content.It is found that：1）When the reservoir develops fine conglomerate,its permeability is the best;2）the permeability of reservoir with the secondary pore is better than that with the original pore;3）the permeability decreases with the increase of the clay content.Therefore,on the basis of the lithology,apermeability model using porosity and clay contents was established.The actual application of the model shows that the consistency between the calculation results and the core analysis is well,which provides a reliable basis for the fine evaluation of the reservoir in the later period.