超压盆地中泥岩的流体压裂与幕式排烃作用

流体压裂是在异常高流体压力体系的低渗泥岩中流体活动的主要输导通道。流体压裂不仅导致低渗泥岩的幕式压实作用，而且为油气运移，储集的研究提供了新的理论模式。超压盆地泥岩的压实演化可划分为两个阶段，即连续压实和幕式压实阶段，其中幕式压实阶段又可根据导致流体压裂的主控因素进一步划分为两个亚阶段，即水力压裂和生烃压裂，前者主要由于泥岩欠压实和新生流体源的增压所致，后者则主要由于泥岩中有机质生烃及烃类裂解后增

HYDROFRACTURING AND ASSOCIATED EPISODIC HYDROCARBON EXPULSION OF MUDSTONES IN OVERPRESSURED BASIN

Hydrofracturing is one way of fluid expulsing from impermeable mudstones in overpressured formation system,which not only results in episodic compaction of mudstones,but also affects on the migration and trap of hydrocarbon in a new way.The compacting processes in impermeable mudstones of overpressured basin can be classified into two stages,i.e.continue and episodic compaction stages.According to the main effect parameters of hydrofracturing,the episodic compaction stage includes hydraulic fracture and hydrocarbon generated cracking.The former is resulted from disequilibrium compaction and new generated fluid from the transfer of clay minerals,and the latter is resulted from hydrocarbon generated or hydrocarbon thermal dispersion.Hydrofractures in mudstones dramatically change the permeability of rocks,and also provide a excellent fluid flow way for hydrocarbon to expulsing from source rocks.So,episodic hydrofracturing results in episodic hydrocarbon expulsion.