Abstract:

The formation of the reservoirs of the second and third mumbers of Dengying Formation in Ziyang,Sichuan Province,is closely connected with lithological microfacies and their assemblages.The strata are composed of 12 kinds of lithological microfacies and 5 microfacies assemblages.Among them light micrite dolomite,sparry dolarenite,micrite sparry oolite dolomite and some stromatolitic dolomite,distributed in the middle and upper part of each microfacies assemblage,are favourable for the formation of the reservoirs.The high frequent overlap of the microfacies and their assemblages in vertical direction result in lots of thin reservoir layers.In lateral,Block-1 centering well Zi-3 and Zi-7 and Black-2 centering well Zi-4 have the best lithological microfacies and assemblages for the formation of the reservoirs.