Abstract:

The pore texture and origin of the Carboniferous-Permian reservoirs in the south slope of wulangar rise in the north part of Ordos Basin is studied by casting thin section,injecting mercury,SEM,etc..The result indicates that pore texture is not so good and the pores are mainly very small intra-interstitial materials and dissolved intragranular ones.The capillary pressure curves show dominatly type-4 and -5,especially type-5.Thepore texture therefore should be defined as grade 4 or grade 5.The reason caused the poorpore texture is related to the complicated and intensive diagenesis.Within 4 diagenesis stages,the compaction,filling and replacement in the first two stages greatly decreased the pore spaces,though there was dissolution in the third stage,they did not develop well and were filled again in the last stage.According to the fact that well No.Y17 has producedgas,the pores of the intra-interstitial kaolinite may still be available reserving spaces.