辽河油田曙光区兴隆台油层隔层特征及其封隔能力评价

CHARACTERISTICS OF INSULATING LAYERS AND EVALUATIONOF SEALING ABILITY FROM XINGLONGTAI OIL HORIZON OF LIAOHE OILFIELD

辽河油田曙光区兴隆台稠油油层中隔层按岩性可分为泥岩类、砂 (粉砂 )质泥岩类、泥质砂 (粉砂、砾 )岩类。不同类型隔层的特征明显不同 ,渗透率以泥质砂 (砾 )岩类最高 ,其次为砂质粉砂质泥岩类 ,泥岩类最低 ;突破压力以泥岩类最高 ,泥质砂 (粉砂、砾 )岩类最低 ,砂 (粉砂 )质泥岩类介于中间 ;热导率、比热容和热膨胀系数以泥岩类最高 ,次为砂 (粉砂 )质泥岩类 ,泥质砂 (粉砂、砾 )岩类最低。根据隔层的突破压力、中值半径、小孔隙含量、渗透率和厚度等将本区油层隔层分为 3类、6个亚类 ,其中泥岩类为Ⅰ类 (封闭型 )隔层 ,对蒸汽的阻隔能力最强 ,砂(粉砂 )质泥岩为Ⅱ类 (限制 封闭型 )隔层 ,阻隔能力介于Ⅰ类与Ⅲ类之间 ,泥质砂 (粉砂、砾 )岩类为Ⅲ类 (限制型 )隔层 ,阻隔蒸汽能力最低。根据Ⅰ类和Ⅱ类隔层分布系数、<1m厚隔层分布系数及隔层分布连续性 ,综合评价认为 ,兴隆台稠油层 7套隔层中有 4套为好隔层 ,1套为较好隔层 ,2套为差隔层。

The insulating layers of Xinglongtai dense oil horizon in Shuguang District,Liaohe Oilfields could be divided into three types such as mudstone,sandy mudstone,argillaceous sandstone.Their properties differ differently with each other.The argillaceous sandstone possesses the highest permeability then the sandy mudstone;mudstone has the lowest permeability but possesses the highest breakpressure;the argillaceous sandstone has the lowest breakpressure. As for thermal conductivity,specific heat and thermal expansion coefficient, mudstone is the highest and argillaceous sandstone is the lowest.According to the breakpressure,midvalue radius,permeability and thickness,the insulating layers could be divided into three types and six subtypes. Among all the seven layers in the study area,four of them are fine,two of them are secondary,two of them are poor.