Multiphase Calcite Cementation and Fluids Evolution of a Deeply Buried Carbonate Reservoir in the Upper Ordovician Lianglitag Formation, Tahe Oilfield, Tarim Basin, NW China

Figure 5

Photomicrograph pairs in transmitted light (a, c, and e) and cathodoluminescence (b, d, and f) of samples illustrating the main cement features in the Lianglitag Fm. carbonate rocks. The white circle is the position of the SIM analysis point; the white digit is δ¹⁸O and the blue digit is δ¹³C. (a, b) The dissolution pore is mainly cemented by C2–C5, and C2 is obviously cut by C3, indicating that it predated the formation. Sample from 5893.10 m, well T738. (c, d) The dissolution pore is cemented by C1–C6. Sample from 5779.36 m, well T904. (e, f) C6 with red luminescence fills the pore and the remaining effective pore is seen. Sample from 6089.9 m, well S110.

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