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)

Figure 10

Thin section images of pore bitumens and oil-filled inclusions under transmitted light (a, c, e, g, i, k, m) and UV light (b, d, f, h, j, l, n). ((a) and (b)) Sample 4514.65 m, well D-7: yellow fluorescing oils absorbed over chlorite coats. ((c) and (d)) Sample 4548.6 m, well D-8: pore solid bitumens with yellow fluorescing oils absorbed on walls. ((e) and (f)) Sample 4548.6 m, well D-8: intergranular pore filled with nonfluorescent solid bitumens with yellow fluorescing oils absorbed inside. ((g) and (h)) Sample 4138.03 m, well D-7: blue-white fluorescing oils occurring within cleavage planes of detrital feldspars. ((i) and (j)) Sample 4837.5 m, well D-1: yellow fluorescing oil inclusions occurring along healed microfractures terminating at detrital quartz margin. ((k) and (l)) Sample 3970.9 m, well D-6: blue-white fluorescing oil inclusions healed microfractures in detrital quart. ((m) and (n)) Sample 4258.85 m, well D-6: yellow fluorescing oil inclusions in calcite cements. Framework grains: quartz (Qtz), feldspar (Fs), and volcanic rock fragment (VRF); cement: calcite (Cal) and chlorite coat (Chl-c); solid bitumen (S-bit).

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