渝东北双家坝气田黄龙组沉积微相分析

Sedimentary micro-facies analysis of Huanglong Formation in the Shuangjiaba gas field,northeast Chongqing

上石炭统黄龙组是渝东北双家坝气田天然气藏的主力产层。依据钻井、岩心、薄片、测井资料,并结合岩石学及古生物等的综合研究,建立了研究区石炭系黄龙组沉积模式。认为双家坝气田黄龙组沉积发育有萨勃哈、海湾陆棚2个沉积相带,具水体逐渐加深和范围向陆上超与扩大的海侵序列。根据沉积相标志又可进一步划分出6个亚相带和8个微相带。依据单井的沉积相研究成果进一步编制了黄龙组一段(C2hl1)、黄龙组二段(C2hl2)、黄龙组三段(C2hl3)沉积微相展布图,其中黄龙组二段的复合颗粒滩、砂屑滩、生屑滩微相是本区的有利沉积相带,为双家坝气田石炭系主力产气相带。

Abstract：The Upper Caxboniferous Huanglong Format/on in the Shuangjiaba gas field of northeast Chongqirtg is the principal producing formation of natural gas pool. Based on the drilling, cores, thin slice and logging information,, in combination with a comprehensive study of petrology, paleobiology and well logging, the authors established a sedimentary model of Huanglong Formation. Studies show that the Huanglong Formation consists of two types of sedimentary systems, i.e., sabkha and continental shelf. The water bodies of two sedimentary systems deepened gradually and expanded, forming a transgression sequence. Six subfacies and eight microfacies were recognized based on the signature of sedimentary facies. On the basis of sedimentary facies of each well, the plane distributive map of sedimentary micro-facies about the first Member （C2h/1）, the second Member （C2h/2） and the third Member （C2h/f3） of the Huanglong Formation was compiled. Composite particles beach, calcarenite beach and bioclast beach are the most favorable microfacies. The second section of Huanglong Formation was the main gas-producing area in the upper Carboniferousperiod.