Sweet spot evaluation and exploration practice of lacustrine shale oil of the second member of Kongdian Formation in Cangdong sag, Bohai Bay Basin

HAN Wenzhong,ZHAO Xianzheng,JIN Fengming,PU Xiugang,CHEN Shiyue,MU Liangang,ZHANG Wei,SHI Zhannan,WANG Hu

Table 5 Drilling results of shale oil horizontal wells targeting Kong 2 Member in Cangdong sag.

Well name Tested section/m Clusters Fracturing fluid injected per meter/m3 Sand injected per meter/m3 Average fracture half- length/m Production time/d Cumulative oil production/t Average daily oil production/t Current daily oil production/t Cumula- tive decline rate/% Flowback rate/% Dynamic fluid level/m Remark PS3 PS2 1701H 225 716 54 36.4 1.48 90.7 560 7637 13.6 8.9 64 42.0 -1463 Pumping for 365 d, with bridge plugs not drilled 1702H 527 756 66 32.0 1.05 94.3 623 10 315 16.6 12.9 40 35.0 0 Natural flow, with bridge plugs drilled 1H 94 310 46 35.8 2.21 87.0 452 5034 12.5 5.84 32 13.7 -253 Pumped with 38 mm pump, with bridge plugs not drilled 2H 556 67 39.8 2.42 70.0 458 5136 13.9 3.64 21 14.6 -1952 Pumped with 57 mm pump, with bridge plugs drilled 3H 507 67 37.3 2.10 76.0 439 4026 10.0 3.94 33 13.7 -2084 Pumped with 44 mm pump, with bridge plugs drilled