关键词: 复兴油田, 凉高山组, 页岩油气, 地质特征, 关键技术

Abstract: Recently, the Ministry of Natural Resources has approved the first-phase proven geological reserves jointly submitted by Sinopec Exploration Company and Jianghan Oilfield for the Middle Jurassic Lianggaoshan Formation in Fuxing area, including 2 010.06×10⁴ tons of crude oil and 123.52×10⁸m³ of natural gas. This marks the emergence of Fuxing oilfield, the first shale oilfield in Sichuan Basin. To further advance the geological theory of terrestrial shale oil and gas accumulation, as well as key exploration technologies, this study systematically analyzes the geological characteristics of terrestrial shale oil and gas in the Jurassic Lianggaoshan Formation based on exploration practices in Fuxing oilfield. The study identifies the main controlling factors for the enrichment and high productivity of shale oil and gas, and proposes key exploration technologies tailored to terrestrial shale oil and gas. Research findings indicate that the upper oil-bearing shale in the lower submember of Member 2 of Lianggaoshan Formation formed in a warm, humid, strongly reducing, and highly productive freshwater environment, characterized by well-developed silt laminae and a high content of feldspar minerals. The combination of Type Ⅱ₁ toⅡ₂ kerogens, medium to high organic carbon content, a high degree of thermal maturity, and high-quality crude oil indicates the development of volatile oil reservoirs in shale. The reservoirs exhibit distinctive geological characteristics, including predominantly inorganic pores and fractures, large pores and throats, integrated pore-fracture networks, and fracture-enhanced drainage. The lacustrine dark shale in the upper oil-bearing layer of lower submember of Member 2 of Lianggaoshan Formation is characterized by excellent material foundation, favorable accumulation configuration, good preservation conditions, and effective fractures, making it a geological-engineering dual sweet spot. This improves reservoir stimulation and enhances hydrocarbons production. To address the challenges associated with terrestrial shale exploration and evaluation, continuous efforts and breakthroughs have been made in well logging, geophysical prospecting, and engineering techniques, thus creating a series of novel, applicable technologies. The discovery of Fuxing oilfield plays a crucial role in advancing the understanding of terrestrial petroleum geology, innovating key exploration technologies, and ensuring national energy security.

Key words: Fuxing oilfield, Lianggaoshan Formation, shale oil and gas, geological characteristics, key technologies