泥质砂岩液相渗透率计算新方法  

A new method for calculating fluid permeability of shaly sandstone

作　　者：王亮[1,2] 毛志强[3,4] 孙中春[5] 罗兴平[5] 宋永[5] 王振林[5] 

机构地区：[1]西南石油大学地球科学与技术学院,成都610500 [2]国土资源部沉积盆地与油气资源重点实验室,成都610081 [3]油气资源与探测国家重点实验室,北京102249 [4]北京市地球探测与信息技术重点实验室,北京102249 [5]新疆油田公司勘探开发研究院,新疆克拉玛依834000

出　　处：《地球物理学报》2015年第10期3837-3844,共8页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41504108);国土资源部沉积盆地与油气资源重点实验室(zdsys2015003);西南石油大学青年教师"过学术关"基金(201499010020);四川省教育厅科技项目资助(15ZB0057)联合资助

摘　　要：液相渗透率描述了岩石的渗流特性,是评价储层与预测油气产能的重要参数.液相渗透率是指盐水溶液在岩石孔隙中流动且与岩石孔隙表面黏土矿物发生物理化学作用时所测得的渗透率;液相渗透率的实验测量条件更加接近实际地层泥质砂岩的条件,使得液相渗透率更能反映地层条件下泥质砂岩的渗流特性;然而,现有的液相渗透率评价模型较少,且模型未能揭示液相渗透率与溶液矿化度之间的关系.基于此,开展了液相渗透模型推导与计算方法研究;文中首先将岩石等效为毛管束模型,推导建立了液相渗透率与比表面、喉道曲折度、总孔隙度、黏土束缚水孔隙度等参数之间的关系;其次,根据岩石物理体积模型,推导建立了黏土束缚水孔隙度与阳离子交换容量、溶液矿化度等参数的关系;最终,将黏土束缚水孔隙度引入液相渗透率计算公式,建立了基于总孔隙度、阳离子交换容量、溶液矿化度、比表面、喉道曲折度等参数的液相渗透率理论计算模型.液相渗透率计算模型与两组实验数据均表明,液相渗透率随阳离子交换容量的增大而降低,随溶液矿化度的增大而增大.然而,液相渗透率理论计算模型的实际应用中喉道曲折度、比表面等参数求取困难,直接利用理论模型计算液相渗透率受到限制.在分析液相渗透率与孔隙渗透率模型的基础上,建立了液相渗透率与空气渗透率之间的转换模型,形成了利用转化模型计算液相渗透率的新方法.为进一步验证液相渗透率与空气渗透率转化模型的准确性,基于两组实验数据,利用转换模型计算了液相渗透率;液相渗透率计算结果与岩心测量液相渗透率实验结果对比显示,液相渗透率计算结果与实际岩心测量结果吻合较好,文中建立的液相渗透率与空气渗透率转化模型合理可靠.The fluid permeability describes the flow characteristics of rock,which is an important parameter in the evaluation of reservoirs and prediction of oil and gas production.The fluidpermeability can be measured when brine solution flow in pores and has physical and chemical effects with clays which adhere to or coat the grains.The measurement conditions of fluid permeability are similar to the actual conditions of shale sandstone reservoirs,so this parameter is considered to be better expression of the flow characteristics of shale sandstone reservoirs.However,there are few evaluation models of fluid permeability reported,and the existing models cannot reveal the relationship between fluid permeability and salinity of solution.To address this issue,this paper presents a model for fluid permeability calculation.In this study,based on the assumption that the shaly sand can be simplified as a capillary tubes model,a expression of fluid permeability in terms of the surface area,tortuosity of throat,total porosity,and bound water porosity of clay is deduced.In addition,according to the physics volume model,the relationship of bound water porosity of clay to cation exchange capacity and salinity of solution is derived.Finally,by means of introducing the bound water porosity of clay to the expression of fluid permeability,a theoretical model of fluid permeability in terms of total porosity,cation exchange capacity,salinity of solution,surface area,and tortuosity of throat is deduced.The theoretical model and two sets of experimental data of fluid permeability show that the fluid permeability decreases with the increasing cation exchange capacity,and increases with the growing salinity of solution.However,in the application of the model of fluid permeability,it is difficult to calculate the parameters of the surface area and tortuosity of throat.So the application of the theoretical model to calculate the fluid permeability is limited.Based on the analysis of the models of fluid permeability and air permeability,a transfor

关 键 词：液相渗透率 阳离子交换容量 溶液矿化度 泥质砂岩 

分 类 号：P631[天文地球—地质矿产勘探]