Fracture development and hydrocarbon accumulation in tight sandstone reservoirs of the Paleogene Huagang Formation in the central reversal tectonic belt of the Xihu Sag, East China Sea

ZHOU Xinhuai,XU Guosheng,CUI Hengyuan,ZHANG Wu

Fig. 4. Typical microfractures on thin sections of Huagang Formation promote dissolution. (a) Well D-2, 4614.70 m, 5×10, dissolved fractures on grain margin; (b) Well D-2, 4613.10 m, 5×10, strong compaction, line contact, fractures not developed; (C) Well E-1, 4647.46 m, 10×10, dissolution on both ends of the penetrating fracture; (d) Well E-1, 4646.26 m, 10×10, dissolution on both ends of the penetrating fracture.