| Pore space is characteristic in Lower Silurian Longmaxi shale reservoirs in southeastern Chongqing and northwestern Guizhou areas. Shale samples are collected from Wells YY-1, XY-1 and TY-1 in the areas. Observed with SEM, four types of pores can be recognized, including intergranular pores, intragranular pores, organic-matter pores and microfractures, most of which are macropores (＞50nm) and mesopores (2～50nm). Mineral intercrystalline pores are common in intergranular pores. Mineral aggregates, such as pyrite framboids, are general in intragranular pores. Organic-matter pores are mostly round or elliptic with large sizes as macropores and/or mesopores. By the micro-CT scanning to part of samples, the 3-D structure models of nanometer-scaled pores are re-established. It is shown that most micropores are isolated or stripped with poor pore networks and connectivity in Longmaxi shales. |
