Table 3 Types and characteristics of reservoir spaces in the metamorphic rock reservoir from the central paleo-uplift belt of the Songliao Basin.
Reservoir space types | Origin | Characteristics |
|---|---|---|
Intergranular pores | Primary intergranular pores in protolith and pores formed among metamorphic mineral | Angular, with a small pore size, visible under a scanning electron microscope |
Dissolved pores | Leaching, dissolution by formation fluid | Generally development along fractures, irregular shape |
Structural microfractures | Microfractures formed under tectonic stress | Irregular, extending far |
Weathering microfractures | Formed by physical weathering and breaking along the schistosity plane | Linear, funnel-shaped, developed in schist |
