成像测井技术在研究砂砾岩沉积构造中的应用

Application of Fullbore Formation MicroImager (FMI) to Study of Glutenite Sedimentary Structures in Jiyang Depression

以济阳坳陷陡坡带为例,对砂砾岩的成像测井响应进行了研究,建立了岩心-图像对应关系,在此基础上,利用FMI成像图识别岩石沉积构造,判别古水流方向。FMI成像图的颜色及其形态变化是沉积构造识别的主要依据,层理通过层内颜色微细变化显示出来,层面表现为形态各异的线形颜色突变界面,纹层连续性破坏或纹层面扭曲等特征指示同生变形构造的存在;根据图像解释的砂砾岩交错层理倾向,可推断古水流方向。

Taking steep slope region of Jiyang depression as an example, the FMI logs of glutenite are analyzed, setting up the core vs. image relationship, based on which, the glutenite sedimentary structures and paleocurrent directions could be identified. The FMI map＇s colors and features are helpful to identification of the sedimentary structures by the fact that different kinds of beddings such as horizontal and parallel bedding, planar, trough and wavy cross bedding, graded bedding and massive bedding can be discerned on the images by fine changes of color within a stratum and dip azimuth between lamina surfaces picked up on them. Penecontemporaneous deformation structures such as load structure, sand ball or pillow and deformed bedding are easily recognized by similar characteristics on images from outcrops or cores. The paleocurrent direction can be deduced by dip direction of cross laminae of glutenite interpreted on images.