川东上二叠统长兴组生物礁控储层的形成

FORMATION OF REEF-BOUND RESERVOIRS OF UPPER PERMIAN CHANGXING FORMATION IN EAST SICHUAN

川东长兴期生物礁有五类:台隆及台坪点礁,台缘礁,台缘礁后点礁,近局限海点礁。典型点礁的形成与二叠纪末地壳颤动有关,造成袋岩式礁核带与间歇滩带相间旋回。相带选择性多期白云石化及溶蚀作用,造成礁间歇滩及礁翼等储层。

There are five types of organic reefs of Changxing stage in East Sichuan:patch reefson carbonate platform rises and flat,shelf margin reefs and patch reefs in back reef la-goons,and patch reefs near restricted sea.The formation of typical patch reefs was related to the fluctuation of earth crust atthe end of the Permian,forming reef core facies,constructed by saccoliths of bound-stones,interchangeably with intermittent shoal facies.Facies-selective dolomitization anddissolution in different stages resulted in the reservoirs of intermittent shoals,reef flanks,etc..The paper deals emphatically with the sedimentology and diagenesis of the reef com-plex.