Abstract: In May 2022, Well Xiayan 26, located in the west wing of Xiayan uplift, Junggar Basin, obtained high-yield industrial oil flow in Carboniferous and Triassic Baikouquan Formation, and had good oil and gas show in Permian Xiazijie Formation and Xiawuerhe Formation, demonstrating that Xiayan uplift has a prospect of three-dimensional exploration in multi-layer system. At present, there is less systematic research on the enrichment conditions, accumulation models, and main controlling factors of oil and gas in multi-layer system in Xiayan uplift, which restricts the process of oil-gas exploration and development. Based on the latest seismic and drilling data, the paper detailedly describes the geological structure of Xiayan uplift and its surrounding areas, systematically summarizes the oil and gas accumulation conditions and models of Xiayan uplift, and points out favorable zones for future exploration. Xiayan uplift is vertically divided into four tectonic stratigraphic units:Carboniferous, Permian, Triassic to Jurassic, and Cretaceous to Cenozoic, and presents a tectonic framework of "alternative distribution of three nosing structures and three depressions" on the plane. Among them, the nosing structure zones of Well Madong 3 (No.1), Well Xiayan 2 (No.2), and Well Shinan 4 (No.3) present a broom-like pattern of "spreading out at the southwest end and converging at the northeast end". No. 1 and No.2 nosing structure zones in the west develop a near-source new bed-generating and old bed-storing accumulation model with long-span side connection between source and reservoir, and the source rock is the mud shale of Lower Permian Fengcheng Formation in Mahu sag; No.3 nosing structure zone in the east of the uplift develops a far-source new bed-generating and old bed-storing accumulation model with vertical/horizontal adjustment of multi-transport system, and the source rock is the mud shale of Lower Permian Fengcheng Formation and Middle Permian Xiawuerhe Formation in the Well Pen 1 West sag. The top of Carboniferous buried-hill horsts in No.1 and No.2 nosing structure zones of Xiayan uplift develops large-scale volcanic rock weathering crust pore-fracture type reservoirs, which has good oil and gas preservation conditions, and is the most realistic favorable zone for carrying out fine exploration, proving large-scale reserves, and increasing reserves and production.

Key words: Junggar Basin, Xiayan uplift, third-order tectonic unit, accumulation mode, exploration prospect

摘要： 2022年5月,位于准噶尔盆地夏盐凸起西翼的夏盐26井在石炭系和三叠系百口泉组获高产工业油流,在二叠系夏子街组和下乌尔禾组见良好的油气显示,证实夏盐凸起具备多层系立体勘探前景。目前对夏盐凸起多层系油气的富集条件、成藏模式及主控因素的系统研究比较薄弱,制约了油气勘探开发的进程。基于最新的地震和钻井资料,精细刻画了夏盐凸起及其周缘的地质结构,系统总结了夏盐凸起的油气成藏条件及成藏模式,并指出下一步勘探有利区带。夏盐凸起纵向上划分为石炭系、二叠系、三叠系-侏罗系和白垩系-新生界4个构造地层单元,平面上呈"三鼻三洼相间分布"构造格局,其中,玛东3井(1号)鼻凸带、夏盐2井(2号)鼻凸带及石南4井(3号)鼻凸带呈"西南端散开、东北端收敛"的帚状。凸起西部的1号、2号鼻凸带发育新生古储、源-储大跨度侧接的近源成藏模式,烃源岩为玛湖凹陷下二叠统风城组泥页岩;凸起东部的3号鼻凸带发育新生古储、多输导体系纵/横向调整的远源成藏模式,烃源岩为盆1井西凹陷下二叠统风城组和中二叠统下乌尔禾组泥页岩。夏盐凸起1号、2号鼻凸带石炭系潜山垒块顶部发育火山岩风化壳孔隙-裂缝型规模储层,具备良好的油气保存条件,是下一步开展精细勘探、落实规模储量、实现增储上产最为现实的有利区带。

关键词: 准噶尔盆地, 夏盐凸起, 三级构造单元, 成藏模式, 勘探前景