Characteristics of depositional facies Badaowan Formation, jurassic of Jian 188 well block, Baikouquan oil field.

Guided by the sedimentary geology and well logging geology,this paper studies the drilling data,the well logging data,and the well cores and outcrop data of more than 170 wells in Jian 188 well block,Baikouquan oilfield.The Badaowan Formation is divided into 12 substrata according to the correlation methods of sedimentary cycles,index horizons and the similarity of the resistivity curves.The sedimentary facies of each substratum is analyzed and the Badaowan Formation is found to be a braid river sedimentary facies developed in a humid-half arid climate and environments.Three sedimentary subfacies are developed in Badaowan Formation: the main river channel,the branch river channel and the fluvial-flood plain; four sedimentary microfacies are developed in Badaowan Formation: the channel,the channel bar,the flood plain and the marsh.The main river channel and the branch river channel are mainly developed in J1b8-5~J1b7 substrata,and the provenance comes from the northwest of the target area.The river channel and the flood plain are mainly developed in J1b6~J1b3 substrata,and the provenance comes from the northwest and the north of the target area.The marsh is mainly developed in J1b2~ J1b1 substrata,and the provenance comes from the northwest of the target area.The arid climate prevailed when the lower Badaowan Formation was deposited and it became humid when the upper Badaowan Formation was deposited.The Badaowan Formation has undergone an integral aggression-regression process according to the comprehensive analysis of the sedimentary evolution history.