Characteristics of Middle-Lower Ordovician Ultradeeply Buried Carbonate Reservoirs in Shunbei Area, Tarim Basin—A Case Study from Well SHBP1

Figure 3

The upper unit characteristics of Well SHBP 1. Microscopic/petrographic characteristics of samples in the upper unit: (a) Gray siliceous dolomite. The dissolution of dolomite and matrix breccia can be found in the fracture, and the dissolution is filled with siliceous and calcite cement, 8453.72-8453.82 m; (b) Fine-medium crystal dolomite. Corrosion pores, 20-50 mm in diameter, are filled with calcite and siliceous parts. There are directional distribution characteristics in the pores, and honeycomb dissolution can be found along the cracks, 8451.12-8451.24 m; (c) Microscopic photo of (a) quartz grains in the intercrystallite of honeycomb dolomite develops the secondary calcite, 8453.74 m, PPL; (d) Siliceous fine-monocrystalline dolomite. Suture Wire Cut Dolomite, 8452.14 m, PPL; (e and f) Powder-fine dolomite. Honeycomb structure, edge of siliceous, and giant crystal calcite, 8450.02 m, PPL.

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