鄂尔多斯盆地页岩油体积压裂技术实践与发展建议

Practice and Development Suggestions for Volumetric Fracturing Technology for Shale Oil in the Ordos Basin

  • 摘要: 体积压裂技术可提高鄂尔多斯盆地页岩油单井产量,但低油价条件下仍可能无法实现经济有效开发,原因是体积压裂技术思路、压裂技术模式、压裂参数体系等不够合理。为此,长庆油田根据该盆地延长组长 7 段页岩油体积压裂矿场实践和室内模拟研究结果,转变了体积压裂技术思路,研究形成了“大井丛、长水平井、细分切割、分簇射孔、可溶球座、变黏滑溜水”压裂技术模式,优化了体积压裂参数体系;并结合该盆地页岩油储层地质特征,系统分析了体积压裂增产机理和关键技术。分析认为,对于页岩油在储层中渗流机理的认识,已逐步由常规油藏单一的有效驱替机理转变为有效驱替和油水渗吸置换复合机理;该盆地形成的体积压裂技术模式,其关键技术材料全部自主研发,且具有很好的现场应用效果。为了深化与提升该盆地页岩油体积压裂技术,追求更高产能目标,建议进一步研究压裂增产机理、优化关键技术参数、发展体积压裂可视化技术。研究结果可为页岩油水平井体积压裂优化设计提供依据,对同类储层的压裂改造具有借鉴作用。

     

    Abstract: The use of volumetric fracturing technology can greatly increase the output of single well of shale oil in the Ordos Basin, but it is difficult to achieve economic and effective development under the condition of low oil prices due to the fact that the technical idea, technical mode and parameter system of fracturing are not reasonable enough. For this reason, based on field practice and laboratory test results of volumetric fracturing of shale oil at the Chang 7 Member of the Yanchang Formation in the Ordos Basin, the technical idea for volumetic fracturing was changed, thereby forming the technical mode of “large well clusters, long horizontal wells, subdivision cutting, cluster perforation, soluble ball seats, and variable-viscosity slickwater”. Then, the parameter system for volumetric fracturing was optimized. The mechanism and key technology for fracturing stimulation were systematically analyzed with the geological characteristics of the shale oil formation in the basin. The research results showed that the understanding of the seepage mechanism of shale oil in the reservoirs has gradually evolved from a single effective displacement mechanism for conventional reservoirs to a compound mechanism of effective displacement and oil-water imbibition displacement. The technical mode of volumetric fracturing proposed for the Ordos Basin was researched and developed independently, and its utilization obtained good field application results. In order to deepen and improve the volumetric fracturing technology and obtain higher productivity, some suggestions for the development of shale oil in the basin were put forward, including the further study of mechanism for fracturing stimulation, optimization of key technical parameters, and development of visualized volumetric fracturing technology. The research results can provide a basis for the optimal design of volumetric fracturing of horizontal shale oil wells, and can be used as a reference for the fracturing stimulation of similar reservoirs.

     

/

返回文章
返回