Formation conditions and enrichment model of retained petroleum in lacustrine shale: A case study of the Paleogene in Huanghua depression, Bohai Bay Basin, China

ZHAO Xianzheng,ZHOU Lihong,PU Xiugang,JIN Fengming,SHI Zhannan,HAN Wenzhong,JIANG Wenya,HAN Guomeng,ZHANG Wei,WANG Hu,MA Jianying

Table 1 Relationship between provenance supply and mineral composition.

Match A/km B/km B/A Felsic content/% TOC/% Clay content/% Brittleness index/% Match between lacustrine size and sediment supply Representative layer Moderate match between lacustrine size and sediment coverage 18.5 8.6 0.46 4-44 (28.8) 0.6-9.4 (3.68) 3-21 (13.9) 33-64 (44.6) No.2 sub- layer Small lacustrine size and strong sediment supply 16.2 10.8 0.67 21-63 (36.9) 0.5-7.3 (1.22) 6-24 (10.8) 40-58 (49.5) No.8 sub- layer Large lacustrine size and weak sediment supply 19.2 3.5 0.18 8-53 (34.1) 0.8-12.4 (6.62) 6-41 (27.8) 22-62 (36.2) No.17 sub- layer