考虑应力敏感和边界层效应的页岩油油藏渗流模型研究

由于页岩油储层孔隙结构复杂，原油渗流过程中存在明显的多尺度效应，而储层中存在应力敏感效应和边界层效应对原油渗流特征影响使得其流动机理更加复杂。基于毛细管模型，结合边界层和应力敏感理论，建立了页岩油储层渗流新模型并进行了验证。根据新模型分析了应力敏感效应、边界层效应对页岩油渗流特征的影响。研究结果表明：页岩油新渗流模型与渗流实验结果拟合性好，具有较高可靠性；边界层效应和应力敏感效应是影响潜江页岩油储层渗流特征的主要因素；对于含有微裂缝和溶蚀孔的页岩油储层，应力敏感效应是影响储层渗流特征的主控因素；随着压力的梯度的增加，影响渗流特征的因素由边界层和应力敏感效应的综合作用所决定。通过该研究，加深了影响页岩油油藏渗流特征相关因素的认识，为合理开发页岩油油藏提供了理论依据。

A mathematical model of shale oil reservoir considering the effect of stress sensitivity and boundary layer

Because of the complex of pore structure for the shale oil reservoir, the multi-scale flow was obviously existed in the process of the seepage flow of crude oil. In addition, the flow mechanism of the crude oil was become more complicated due to the effects of stress sensitivity and boundary layer in the seepage flow of the shale oil reservoir. Based on the capillary model and integrated with the stress sensitivity as well as boundary layer theory, a new mathematical model for seepage flow in the shale oil reservoir was modeled, and verified by the experiment results. According to the new model, the effects of the stress sensitivity and boundary layer for the seepage flow of shale oil reservoir were analyzed. The results show that the analysis results obtained from the new model are comparable to the results from the experiment, which could be reflected to reliability of the new model. The boundary layer and stress sensitivity have a main effect on the seepage flow characteristics for the Qianjiang shale oil formation. For the shale oil formation contained with the micro-fracture and the dissolved pore, the seepage flow characteristic is the main dependent upon the effect of stress sensitivity. The seepage flow characteristic is dependent on the combined effects of boundary layer and stress sensitivity as the pressure gradient increased. Through this study, the affecting factors of the seepage flow of the shale oil reservoir have drastically enhanced appreciation, and this result offers a theoretic basis for rational development of the shale oil reservoir.