Diagenetic Heterogeneity of Deep Sandstones and Its Relationship to Oil Emplacement: A Case Study from the Middle Jurassic Toutunhe Formation in the Fukang Sag, Central Junggar Basin (NW China)

Table 2

Stable carbon and oxygen isotopic compositions of calcite cements in the Toutunhe Formation.

Well	Depth (m)	Calcite type	δ^13C (VPDB)	δ^18O (VPDB)
D-1	4837.5	Late	−6.0	−18.0
D-2	4423.2	Late	−8.4	−16.4
D-3	5506.5	Late	−6.7	−18.0
D-6	3970.9	Late	−7.8	−18.9
D-6	3971.7	Early	−3.1	−13.0
D-6	3974.2	Early	−4.3	−13.4
D-6	4258.85	Late	−8.4	−17.8
D-7	4133.6	Late	−6.8	−17.9
D-7	4138.03	Late	−7.4	−19.0
D-7	4514.65	Late	−5.9	−18.3
D-7	4515	Early	−4.1	−12.9
D-8	4545	Late	−6.5	−17.4
D-8	4548.5	Early	−1.4	−11.2
D-8	4548.6	Late	−8.3	−16.8