关键词: “酒架式开发”模式, 最佳经济效益, 绿河组, 混积岩体系, 陆相页岩油, 尤因塔盆地

Abstract: Uteland Butte member in Green River Formation is a typical lacustrine shale oil formation in Uinta Basin, USA. Since 2011, exploration and development of Uteland Butte member have undergone two major shifts, i.e., from conventional targets to overpressured shale reservoirs in the central lake basin, and from conventional development method to horizontal well drilling and volume fracturing. As a result, major breakthroughs have been obtained in beneficial shale oil development, with single-well estimated ultimate recovery (EUR) reaching hundreds of thousands of barrels over the last decade. This high-efficiency development practice has challenged traditional understanding and become an important case study for continental shale oil exploration worldwide. The exploration and development breakthroughs of continental shale oil in Uteland Butte member in Uinta Basin have systematically been reviewed, and geological characteristics, enrichment control mechanisms, and engineering evolution path have been analyzed in detail. The results indicate that the high-efficiency shale oil enrichment in Uteland Butte member was jointly controlled by sedimentary facies, hydrocarbon generation, overpressure, and composite pore structures, and the coupling between complex pore structure and the abnormal overpressure system in the “integrated source rock–reservoir” was particularly critical. In terms of engineering technology, the development method has evolved from early simple fracturing of vertical wells to horizontal well drilling and “rack-style” stereoscopic development, and a comprehensive “sweet spot evaluation—well pattern optimization—staged fracturing” integrated technical system has been established. By using a stereoscopic well pattern, the “rack-style” development mode enables to accurately and synergistically produce multiple vertically superimposed thin sweet spots, providing an important reference for developing similar “thin interbedded and highly heterogeneous” continental shale oil plays in China. On this basis, a differentiated comparative analysis of typical continental shale oil basins in China has been conducted, including Junggar, Bohai Bay, and Songliao basins, which shows significant differences with Uinta Basin in terms of lithology, formation pressure, and in-situ stress. Therefore, a strategy of “tailored and differentiated reference” has been proposed, and specific technical and geological recommendations applicable to each basin have been put forward, aiming to summary the core drivers for multi-element synergic hydrocarbon accumulation, propose a differentiated reference strategy in response to the unique geological challenges of various basins in China, and provide a systematic idea for achieving beneficial oil development.

Key words: “rack-style” development mode, optimal economic benefits, Green River Formation, mixed lithological system, continental shale oil, Uinta Basin