Characteristics and impacts on favorable reservoirs of carbonate ramp microfacies: A case study of the Middle-Lower Ordovician in Gucheng area, Tarim Basin, NW China

LIU Yini,HU Mingyi,ZHANG San,ZHANG Junlong,GAO Da,XIAO Chuantao

Fig. 2. Rock characteristics of Ordovician sedimentary microfacies in the Gucheng area, Tarim Basin. (a) Laminar powdered crystalline dolomite; Well GC601; 6121.64 m; (b) Fine-powdered crystalline dolomite; ordinary thin slices; single polarized light; Well GC10; 6178.40 m; (c) Containing pyrite; ordinary thin slices; reflected light; Well GC10; 6738.31 m, micrite dolomite; (d) Coarse crystalline dolomite; ordinary thin slices; single polarized light Well GC10; 6735.11 m; (e) Coarse-middle crystalline dolomite with dissolved pores; Well GC601; 6148.30 m; (f) Coarse-middle crystalline dolomite with intercrystalline dissolved pores and dissolved pores; cast thin sections; single polarized light; Well GC14; 6443.05 m; (g) Middle crystalline dolomite with intercrystalline pores and intercrystalline dissolved pores; cast thin slices; single polarized light; Well GC9; 6095.52 m; (h) Residual arenaceous structure; fine-middle crystalline dolomite with residual intergranular pores and dissolved pores; cast thin section; single polarized light; Well GC10; 6178.40 m; (i) Oolitic limestone; Well GC12; 6502.55 m; (j) Sparry oolitic limestone; ordinary thin section; single polarized light; Well GC10, 5749.50 m; (k) Well GC8, 5643.28 m, sparry sandy limestone; ordinary thin slices; single polarized light; (l) Well GC13, 6059.22 m, micrite-sparry sandy and silty limestone with cracks filled by calcite; ordinary thin slices; single polarized light; (m) Laminar micrite limestone; Well GC14; 6203.26 m; (n) Microscopic features of the sample in (m); bioclastic micrite limestone; ordinary thin slices; single polarized light; (o) Micrite silty limestone with cracks filled by calcite; cast thin slices; single polarized light; Well GC13; 6737.76 m; (p) Micrite-sparry conglomerate limestone; ordinary thin slices, single polarized light; Well GC8; 5759.25 m.