利用孔隙纵横比定量判断孔隙型海相致密油地层岩性变化点的方法

Quantitative determination of lithology variation of porous marine tight oil by using pore aspect ratio

曹翔宇 3 丁文龙 3 尹帅 3

中国地质大学能源学院，北京 100083 中国地质大学海相储层演化与油气富集机理教育部重点实验室，北京 100083 中国地质大学
页岩气资源战略评价国土资源部重点实验室，北京 100083

School of Energy Resources, China University of Geosciences, Beijing 100083, China MOE Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism, China University of Geosciences, Beijing 100083, China Key Laboratory for Shale Gas Exploitation and Assessment, Ministry of Land and Resources, China University of Geosciences, Beijing 100083, China

泥质质量分数是指示碎屑岩岩性变化的重要指标，其对岩石物性及弹性性质均具有重要影响。对于深层致密油储层，准确预测地层岩性变化尤为重要。文中以塔中X井区孔隙型海相致密碎屑岩地层为研究对象，利用孔弹性Biot理论获取地层岩石弹性参数，重点探讨了孔隙纵横比（α）对地层岩性变化点的指示作用。目的层的基质矿物体积模量（K_o）主要分布在20~60 GPa，基质矿物剪切模量（μ_o）主要分布在10~25 GPa；随着泥质质量分数（V_sh）的增加，孔隙型岩石的α值逐渐降低，具有分段性，砂岩的α值分布在0.25~1.00，泥岩的α值分布在0.01~0.25；岩性转折点所对应的α值为0.25，V_sh为40%，岩石体积模量（K_s）为40 GPa，孔隙度（Φ）为3%，转折端孔隙度可以为储层物性下限的确定提供参考。

The content of clay is an important index to indicate the change of clastic rocks, and it has important influence on the physical properties and elastic properties of rocks. Taking the pore type marine tight clastic rock stratum in the X well area of the Tazhong as the research object, the elastic parameters of the stratum are obtained with the Biot theory and the indication of the α to the change of the formation lithology is discussed. The main ideas are as follows: K_o is mainly distributed in 20￣60 GPa, and μ_o is mainly distributed in 10￣25 GPa; with the increase of Vs_h, the α value of the porous rock gradually decreases, the α value of sandstone in 0.25￣1.00, and the α value of the mudstone in 0.01￣0.25; at the turning point, α=0.25, V_sh=40%, K_s=40 GPa, Φ=3%, the porosity of the turning point can provide a reference for determining the lower limit of reservoir physical properties.

10.6056/dkyqt201606010