准噶尔盆地环玛湖凹陷中——上二叠统有利储盖组合优选

Optimization of Favorable Reservoir-Caprock Assemblages of Middle-Upper Permian in Mahu Sag, Junggar Basin

通过环玛湖凹陷斜坡区中—上二叠统单井层序地层划分和井震层序地层对比,将夏子街组、下乌尔禾组和上乌尔禾组划分为2个二级层序和6个三级层序,识别出夏子街组中—下部、下乌尔禾组下部和上部、上乌尔禾组厚层砂砾岩储集层发育段,以及夏子街组上部、下乌尔禾组中部、上乌尔禾组顶部3套区域性盖层发育段,并优选出3套有利储盖组合:中、下部储盖组合受低位域坡折控制,以岩性、构造岩性油气藏为主;上部储盖组合受二叠系与三叠系、下乌尔禾组与上乌尔禾组之间的大型不整合控制,以地层油气藏为主,埋藏相对较浅,与油源断裂匹配好,具有高效的油气输导体系,是近期油气勘探的重要领域。

This paper presents the sequence stratigraphic classification of single well of the Middle-Upper Permian in slope area surround-ing Mahu sag of Junggar basin, and the sequence stratigraphic correlation of well logging and seismic profile, dividing the Xizijie formation,the Lower Wuerhe formation and the Upper Wuerhe formation into two second-order sequences and six third-order sequences, and recogniz-es the thick glutenite reservoirs of the middle-lower part of Xizijie formation, the lower and upper parts of Lower Wuerhe formation, and Up-per Wuerhe formation, as well as three regional caprocks in the upper part of Xizijie formation, the middle part of Lower Wuerhe formationand the top of Upper Wuerhe formation, by which three favorable reservoir-caprock assemblages are given. The middle and lower assem-blages are controlled by low stand system tract＇s slope break belt, and dominated by lithologic and structural-lithologic reservoirs; the up-per one is controlled by large-scale unconformities of the Permian-Triassic and the Lower Wuerhe formation-Upper Wuerhe formation,dominated by stratigraphic reservoir, and characterized by relatively shallow burial, matching well with oil source faults and high efficientpetroleum transport system, it could be an important area for the recent hydrocarbon exploration.