Differences of Pore Features in Marine Shales between Lower Cambrian and Lower Silurian Formations of Upper Yangtze Area, South China

Lower Cambrian shale and lower Silurian are both typical of oil-prone kerogen siliceous composition, but different in thermal maturities. Porosity differences were determined marine shales between the two shales. Measurements utilized including organic geochemistry, XRD, scanning electron microscopy (SEM) N2 gas adsorption. Pore volume (PV) was approximately 1.5 times higher than that shale, pore surface area (PSA) almost 2.5 shale. possess similar materials, distinctive degrees. Evolution mechanisms types pores, especially matter (OM)-hosted may trigger this features. Pores rigid framework residue primary interparticle pores during burial history. associated with clay flakes can be preserved well adjacent to grains or secondary minerals acting as frameworks grain supporters. Dissolved barely contribute total porosity mean little permeability. Both excessive OM content over maturity detrimental development OM-hosted pores. Rigid particles, flakes, commonly co-exist within matrix. act supporters, confine ample space, first migrates into provides In condition, owing associating matrix good mechanic chemical stability. The significant structural settings result various hydrocarbon explosion efficiency pressure circumstance, which consequently leads features For overpressure circumstance diminish if expels outside system, destroy through compaction. Sustaining abundant (migrated OM) make positive contributions properties, terms numbers, diameters connectivity samples.