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 6

Photographs showing typical diagenetic features in the carbonate rocks of the Lianglitag Fm. (a) Early intragranular dissolution of carbonate minerals developed (most of them were filled during diagenesis), well S111, depth 6108.7 m. (b) Non-fabric-selective dissolution pores and vugs developed, well AD4, depth 6463.42 m. (c) Dissolution vug developed along fractures. Sample from 5794.1 m, well T904. (d) Cavern breccias developed in the Tahe Oilfield, well TH204, depth 5469.2 m. (e) Giant crystal calcite filling the cave. Sample from 6245.95 m, well S116. (f) Fracture filled by green marl in the Tahe Oilfield, well T904, depth 5773.21 m.

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