页岩油渗流机理研究

As one type of unconventional oil resources, shale oil, which is stored in the organic-rich shale, has a huge potential for development. Owing to the existence of nano-scale pores in the low-permeability and low-porosity shale oil formation, the transport in the formation involves complicated mechanisms that are quite different from conventional oil reservoirs and shale gas reservoirs. There is a lack of understanding on the multicomponent-multiphase flow, coupled fluid flow and geomechanics mechanisms for shale oil production. Currently the development of shale oil resources is still in the exploratory stage, while complete and valid theories and methods considering the specific conditions and characteristics of shale oil resources in China have not been formed..In this project, we will investigate the reservoir parameters and microscopic characteristics of pores of typical shale oil formations in China. Based on microscopic scale analysis, through methods such as molecular dynamics simulation, the storage and phase change behavior of oil and gas in the nano-scale pores will be studied as well as their impacts on the relative permeability will be investigated, in order to improve the understanding of the transport mechanisms and develop new models for numerical simulation. Through numerical simulation based on the improved models, sensitivity analysis will be performed to reveal the major controlling factors of shale oil production. On account of the practical field cases of shale oil production and on the basis of the theoretical analysis and lab experimentation, various measures to enhance shale oil production will be explored to provide reference and scientific foundation for the development of new stimulation techniques.

页岩油作为一种储存于富有机质页岩中的非常规石油资源，具有巨大的开发潜力。由于页岩油储层富含纳米级孔隙，具有低孔低渗等特点，渗流过程涉及多组分多相流、流固耦合等复杂机理，与常规油藏、页岩气藏均有显著差别，对于诸多运移机理问题仍然认识不清。我国页岩油的开发仍处于探索阶段，在适合我国具体情况的页岩油渗流机理研究方面，也尚未形成一套完整有效的理论和方法。.本项目将以我国典型页岩油储层为研究对象，系统研究其储层物性参数和微观孔隙特征；从微观尺度出发，借助分子动力学模拟等手段，揭示油气在微纳米孔隙中特殊的赋存状态和相变行为，并分析其对相对渗透率的影响，进而深入分析页岩油的渗流机理，提出新的机理模型；开展数值模拟研究，分析参数敏感性，揭示影响页岩油开采的主控因素；针对页岩油开采中遇到的实际问题，基于理论分析和实验模拟等方法，探索潜在的增产措施，为开发新型增产改造技术提供科学依据。

页岩油储层富含纳米级孔隙，具有低孔低渗等特点，渗流过程涉及多组分多相流、流固耦合等复杂机理，与常规油藏、页岩气藏均有显著差别。.本课题以我国典型页岩油储层为研究对象，研究其流动机理。从分子尺度研究油气在微纳米孔隙中特殊的赋存状态和相变行为，分析其对宏观渗透性的影响。然后，提出宏观尺度的页岩油渗流扩散模型，发展数值模拟技术，通过数值模型分析页岩油开采的主控因素。最后，针对页岩油开采中遇到的实际问题，基于理论分析和实验模拟等方法，探索潜在的增产措施。.本课题实施过程较好地遵循了时间点，通过自行研发或引进现有技术手段，完成了研究目标，解决了任务书中提出的关键问题，形成了四项重要成果，分别是：页岩微观孔隙三维重构和连通性提取技术、页岩油状态方程及相平衡算法、真实干酪根的分子模拟技术、多机理耦合页岩油开采数值模型。