Characteristics and evaluations of reservoirs in Carboniferous-Permian, Northeast China

According to field observations and outcrop sample tests,the conditions of Carboniferous-Permian reservoirs in Northeast China have been studied.Carboniferous and Permian strata are widespread in Northeast China.Both marine and continental facies are found and the marine facies changes to the continental facies from Carboniferous to Permian.Limestone and clastic rock are the dominant formation compounds,and in some region,pyroclastic rock accounts for the largest proportion.The reservoir conditions of Carboniferous-Permian are usually poor.As to Carboniferous strata,the type-Ⅰ reservoirs mainly locate in the southwest of Erlian city,and the type-Ⅱ in the northeast of Erlian city and in Panshi city(south of the Songliao Basin),and the type-Ⅲ in Sanjiang county and the north of the Songliao Basin.As to Permian strata,the type-Ⅰ reservoirs distribute in Yichun city(north of the Songliao Basin) and Guandi town of Linxi county of Erlian city,and the type-Ⅱ around West Ujimqin(east of Erlian city) and Yongji county(south of Songliao Basin),and the type-Ⅲ around Zhenlai county of Inner Mongolia.