Fluid Inclusion Evidence for Oil Charge and Cracking in the Cambrian Longwangmiao Dolomite Reservoirs of the Central Sichuan Basin, China

Figure 5

The Longwangmiao Formation Well MX20 (4605.34-4605.59 m). Fluid inclusion micrographs with petrologic and petrographic observations. (G1) Observed from the core, there are dissolution cavities in the massive granular fine powder crystal dolomite. (G2) Thin-slice scan shows that the dissolution cavities of granular dolomite are filled with solid asphalt. (G3) (-) Multigroup crack cutting dissolution hole edge fog-centered bright-edged dolomite. (G4) (UV) Crack captures bright blue+blue fluorescent two-stage secondary oil inclusions, the main peak wavelength of the microscopic fluorescence spectrum () is between 456 and 495 nm; intercrystalline pores/dissolution pores are filled with solid asphalt. (G5) Fog core bright edge fine powder crystal dolomite. (G6) (UV) Capture the blue primary oil inclusions in bright-edged dolomite, . (G7) (-) The pure gas-phase inclusions are captured in the cracks of the dolomite filled with dissolution pores. (G8) (-) Pure gas-phase inclusions and solid pitch+hydrocarbon gas two-phase inclusions. (-): single-polarized light; (UV): fluorescence.