Table 6 Comparison of physical properties of carbonate reservoirs at different depths.
Area | Khasib formation in the Middle Mesopotamian basin (Lu et al., 2021) | Deng ying formation, Moxi-Gaoshiti area in the Sichuan Basin(Zhang et al., 2022) | Yingshan formation, Tarim Basin (Li et al.,2023) | Qixia formation in the northwestern Sichuan Basin |
|---|---|---|---|---|
Depth | 2500–2800 m | About 5000 m | > 7000 m | > 7000 m |
Mineral | Calcite (> 90%) | Mainly dolomite (> 85%) | Calcite and dolomite | Dolomite (> 90%) |
Lithology | Mainly packstone and wackestone | Mainly algal clotted dolomite and stromatolite dolomite | Lithic feldspathic sandstone | Fine-medium crystalline dolomites, medium- coarse crystalline dolomites |
Pore type | Mainly moldic pore, dissolution pores, intrafossile pore | Mainly intercrystalline pore, moldic pores, intraparticle pore, intercrystalline dissolution pores, vug, and dissolution fractures | fractures, vug | Mainly intercrystalline pore, intercrystalline dissolution pores, vug, and dissolution fractures |
Pore size | 50–300 μm | 0.007–310 μm | 10–300 μm | 10–400 μm |
Permeability | Mainly 1–10 mD | Mainly 0.001–10 mD | Mainly 0.003–0.074 mD | Mainly 0.001–10 mD |
Porosity | Mainly 15–25% | Mainly 0–5% | Mainly 0.03–2% | Mainly 0–5% |
