Pliocene Carbonate reservoir characteristics of Nanyishan in Qaidam Basin,China

Neogene (Pliocene) reservoirs in the Nanyishan in Qaidam Basin are distributed from the upper part of Xia you sha shan Formation(N21) to the lower part of Shang you sha shan Formation(N22).The oil pool is a lithologic layered oil pool controlled by anticline structure.The Pliocene carbonate reservoir rocks in the Nanyishan mainly include grain limestone,grain dolostone,micrite limestone,micrite dolostone,algal limestone.Among them,grain dolostone and grain limestone are the most important reservoir rock,and algal limestone,micrite dolostone and micrite limestone are second.The Pliocene carbonate reservoir spaces in the Nanyishan mainly include primary origin intergranular pore,intergranular dissolved pore,intercrystal pore,intercrystal dissolved pore,solution pore,fracture pore,intrabed crack.Among them,solution pore is the most important reservoir space.The Pliocene best carbonate reservoir in the Nanyishan is grain limestone and grain dolostone,and the second are micrite dolostone,algal limestone and micrite limestone.