Reconstruction of the Cenozoic History of Hydrocarbon Fluids from Rifting Stage to Passive Continental Margin Stage in the Huizhou Sag, the Pearl River Mouth Basin

Table 2

The characteristics of source rocks with different facies of the Eocene Wenchang and Enping Formation in the Huizhou Sag (HZS).

Well	Formation	Facies	TOC (%)	(mg/g)	HI (mg·g^−1)	Ro (%)
241	WC-TST	Shore-shallow lacustrine	0.94	1.29	119.5	/
211	WC-TST	Shore-shallow lacustrine	1.01	1.16	83.5	/
	EP-TST	Swamp	2.81	4.36	135	0.68~1.12
254	WC-TST	Lacustrine	0.73~2.89	2.40~11.26	43.1~334.30	0.67~0.74
			1.56	4.84	153.33
		Delta front	0.49~3.06	2.92~10.82	97.80~301.20	0.75~0.78
			1.44	4.49	173.09
132	WC-TST	Deep lacustrine	1.94~7.68	0.78~28.52	269.20~613.10	0.50~0.55
			3.24	12.77	430.31
	EP-HST	Delta plain	0.82~10.42	1.05~32.83	89.30~300.20	0.41~0.56
			4.72	10.86	187.27
243	WC-TST	Shore-shallow lacustrine	1.52~3.45	2.03~4.14	103.10~136.70	0.79~1.10
			2.15	2.86	124.15
	EP-HST	Fluvial	1.26~8.47	1.17~18.14	47.0~209.80	0.57~0.86
			3.10	5.38	124.72
142	EP-HST	Shore-shallow lacustrine	0.55~3.52	0.62~27.09	64.60~371.20	/
			1.80	4.84	134.84
	EP-TST	Fluvial	0.30~7.26	0.24~18.42	56.70~248.30	/
			2.27	3.79	122.17
232	EP-HST	Delta front	0.96~3.75	1.24~11.29	71.0~282.5	0.64~0.75
			2.01	4.29	139.73
	EP-TST	Delta plain	0.84~4.84	0.74~14.50	30.3~263.1	0.75~0.79
			1.53	2.71	95.29
		Shore-shallow lacustrine	0.84~6.91	0.81~12.32	43.0~115.80	0.87~0.94
			2.14	2.90	53.29
131	EP-HST	Delta plain	0.63~5.98	0.84~21.67	65.0~312.40	0.71~0.96
			2.19	5.66	148.47
	EP-TST	Delta plain	0.47~2.95	0.66~8.58	51.30~218.80	0.76
			1.85	4.04	135.99
		Fluvial	0.55~1.53	1.33~2.72	63.60~113.50	/
			0.92	1.79	88.23
81	EP-HST	Delta	1.06~11.85	3.10~31.0	117.0~260.20	0.53~0.67
			3.23	8.73	201.21
	EP-TST	Fluvial-delta	0.93~4.32	1.90~10.10	87.10~307.70	0.56~0.81
			1.91	5.02	180.45 9
	EP-LST	Fluvial	0.66~11.43	1.80~31.30	40.10~209.40	0.62~0.91
			2.56	5.37	101.55

TOC: total organic carbon content, %; : hydrocarbon generation potential, mg/g; HI: hydrogen index, mg/g; Ro: measured vitrinite reflectance, %. WC: the Wenchang Formation; EP: the Enping Formation; LST: lowstand systems tract; TST: transgression systems tract; HTS: highstand systems tract. Note. The data are presented as in the following example: 0.55~3.52 shows minimum~maximum; 1.80 shows mean (sample number). The value of measured vitrinite reflectance varies with depth, so Ro data are present without average values.