Multi-source genesis of continental carbonate-rich fine-grained sedimentary rocks and hydrocarbon sweet spots

JIANG Zaixing,KONG Xiangxin,YANG Yepeng,ZHANG Jianguo,ZHANG Yuanfu,WANG Li,YUAN Xiaodong

Fig. 4. Carbonate-rich fine-grained rocks formed by biochemical and chemical processes. (a) Well ST1H, 4 206.37 m, the Es3L of Shulu Sag, rhythmic laminated marlstone; (b) fluorescence photo of (a), organic lamina showing bright yellow light, calcite lamina showing yellow green light; (c) Well BY2, 2 816.49-2 816.59 m, lower part of Eq3 of Qianjiang Sag, rhythmic laminated dolomitic mudstone; (d) Well LT1, 1 241.40 m, the Xiguayuan Formation of Luanping Basin, rhythmic laminated dolomitic mudstone with dolomicritic laminae and tuffaceous laminae; (e) Well FY1, 3 332.64 m, the Es4U of Dongying Sag, rhythmic laminated marlstone with sparry calcite laminae; (f) Well FY1, 3 397.56 m, the Es4U of Dongying Sag, sparry calcite laminae and organic-rich clay laminae.