Abstract:

Strong compaction is the most typical diagenesis as well as the principal factor of reduing porosity.Coarse clastic rocks far from coalbed are characterized by extensive cementation and replacement of calcite,while fine sandstones and siltstones interlayered by coalbeds or carbon rich shales show strong compaction.This is related to original sedimental enverinment structural position,coal measure evolution and internal circulating fluid under compaction.