Abstract: The Junggar Basin, as a significant superimposed basin among the petroliferous basins in western China, mainly hosts Carboniferous, Permian, and Jurassic source rocks and three key reservoir-cap assemblages, i.e., Jurassic-Cretaceous sandstone reservoirs overlain by Cretaceous mudstone caps, Upper Permian-Lower Triassic conglomerate reservoirs overlain by the Upper Triassic Baijiantan Formation mudstone caps, and Carboniferous-Lower Permian volcanic/mixtite reservoirs overlain by Middle Permian mudstone caps. This geological framework has resulted in the formation of the Carboniferous, Permian, and Jurassic petroleum systems. Currently, proven oil reserves in the basin are 31.6 × 10⁸t, and natural gas reserves exceed 2 700.0 × 10⁸m³. In recent years, petroleum exploration theory has evolved from hydrocarbon-bearing system to the Whole Petroleum System, leading to a gradual shift in exploration focus from shallow conventional hydrocarbon resources to deep and ultra-deep unconventional targets. PetroChina Xinjiang Oilfield Company (Xinjiang oilfield) has achieved significant breakthroughs in three major Whole Petroleum Systems around Junggar Basin, i.e., new reserve growth in the Permian Fengcheng Formation of the western depression, highly productive hydrocarbon reserves of 100 million tons in Jiamuhe Formation of Zhongguai area, and significant progress of natural gas exploration in the thrust belts of the southern margin of Junggar Basin. In addition, new potential areas for reserve growth have been successively discovered, including the Cretaceous System in the southern Mosuowan uplift, the Carboniferous System along the fault belt of northwest margin of the basin, and the Triassic Baijiantan Formation in Dabasong uplift. The exploration results have revealed the distribution pattern of "gas accumulated in the south and oil accumulated in the north" in the basin, as well as the significant characteristics including the orderly symbiosis of conventional and unconventional oil and gas, occurrence under high to ultra-high pressure environments, well development of fractures, light hydrocarbon phase, and high yield and production efficiency in deep resources. Moving forward, it remains essential to further investigate key aspects such as the unconventional and non-buoyant reservoir forming mechanism of the Permian Fengcheng Formation, the fracture-controlled reservoir characteristics in the complex structural belts along the southern margin of the basin, and the source-reservoir matching of the Carboniferous System. Through continued theoretical innovation and technical advancements, Junggar Basin is expected to achieve 100-million-ton reserves replacement, thus supporting the strategic goal of developing 20 million-ton-scale oil and gas fields in Xinjiang oilfield.

Key words: Junggar Basin, Whole Petroleum System, deep and ultra-deep oil and gas, Permian, Jurassic, Carboniferous

摘要： 准噶尔盆地作为中国西部含油气盆地中重要的叠合盆地,围绕3套主要烃源岩(石炭系、二叠系和侏罗系)、3套储-盖组合(侏罗系—白垩系砂岩储层与上覆白垩系泥岩盖层组合、上二叠统—三叠系砾岩储层与上三叠统白碱滩组泥岩盖层组合和石炭系—下二叠统火山岩/混积岩储层与中二叠统泥岩盖层组合),形成了石炭系、二叠系和侏罗系3大全油气系统,目前已探明石油地质储量为31.6×10⁸t,天然气地质储量超过2 700.0×10⁸m³。近年来,勘探理论从含油气系统向全油气系统不断演进,推动勘探目标由浅层常规油气资源逐步转向深层—超深层非常规油气资源。中国石油新疆油田公司(新疆油田)围绕盆地的3大全油气系统取得突破性进展,在西部坳陷二叠系风城组取得了增储新领域的突破,在中拐地区佳木河组落实了亿吨级高效储量,在南缘冲断带实现了天然气勘探的重要进展,并相继发现了莫索湾凸起南部白垩系、西北缘断裂带石炭系和达巴松凸起三叠系白碱滩组等效益增储新阵地。勘探成果揭示了准噶尔盆地"南气北油"的分布格局,其深层资源展现出常规—非常规油气有序共生、高压—超高压环境、裂缝发育、轻质相态和高产高效等显著特征。未来仍需深化二叠系风城组非常规非浮力成藏机制、盆地南缘复杂构造带裂缝控藏规律和石炭系源-储匹配等关键研究,通过持续的理论创新与技术攻关,准噶尔盆地有望实现亿吨级储量接替,支撑新疆油田建设两千万吨级油气田的战略目标。

关键词: 准噶尔盆地, 全油气系统, 深层—超深层油气, 二叠系, 侏罗系, 石炭系