Chemically Active Elements of Reservoir Quartz Cement Trace Hydrocarbon Migration in the Mahu Sag, Junggar Basin, NW China

Table 2

Major element data for quartz in the D13 well (in wt.%).

Point	Na2O	Al2O3	MgO	SiO2	FeO	MnO	TiO2	CaO	K2O	Total
1	0.002	bdl	bdl	98.98	0.011	0.006	bdl	bdl	bdl	99.00
2	0.013	bdl	bdl	99.45	0.011	bdl	0.038	0.019	0.004	99.53
3	0.011	bdl	0.023	99.29	bdl	0.064	bdl	bdl	bdl	99.39
4	0.006	bdl	bdl	98.68	bdl	bdl	0.149	0.012	bdl	98.85
5	bdl	0.003	0.036	99.74	0.072	0.045	0.038	0.004	bdl	99.94
6	0.032	0.211	bdl	99.06	0.088	bdl	0.056	0.013	0.007	99.46
7	0.015	0.246	0.009	98.03	0.066	bdl	bdl	bdl	0.004	98.37
8	0.085	0.283	0.004	98.19	0.159	0.095	bdl	0.026	0.013	98.85
9	bdl	0.2	bdl	98.15	0.05	bdl	bdl	0.015	0.009	98.42
10	bdl	0.036	0.006	99.53	0.099	bdl	bdl	0.011	0.002	99.68
11	0.027	0.018	bdl	99.03	0.077	bdl	bdl	bdl	0.005	99.16

Note: bdl denotes below detection limit.