【摘要】 通过改进巴西劈裂实验的施力方式联用声发射实时监测技术，实现多尺度渗流的准确模拟，揭示致密油藏非线性渗流规律；依据致密油藏多尺度渗流物理特征，将水平井多级压裂形成的流场结构划分为三大区五小区即Ⅰ水平井筒区、Ⅱ改造区(强、弱改造区)、Ⅲ未改造区(基质动用、未动用区)，并建立水平井多级压裂开发多区耦合非线性渗流数学模型；依据不同时刻供给边界的波及区域，将开发过程划分为水平井筒区—改造区两区耦合和水平井筒区—改造区—未改造区三区耦合2个阶段，推导不同阶段的产量计算公式；依据稳态依序替换方法迭代求解，揭示动态供给边界的扩张规律和致密油藏水平井多级压裂开发产量递减规律。明确启动压力梯度、应力敏感性特征等参数对致密油藏累计产量的影响规律。基于鄂尔多斯盆地致密油藏实际参数，通过模拟衰竭式开发2 000 d。研究结果表明：启动压力梯度和应力敏感性对致密油开采影响显著，其中，改造区的应力敏感性特征是影响致密油藏采出程度的主要因素，其影响幅度约为基质区应力敏感性特征影响幅度的3.14倍。以鄂尔多斯盆地A井为例，合理水平井长度为2 000～3 000 m，合理裂缝半长为200～250 m，目标区块合理生产压差为7～9 MPa。更多还原

【Abstract】 The multi-scale flow was simulated accurately by using the real-time acoustic emission monitoring technology combined with the improved force application mode of Brazilian splitting experiment, and the nonlinear flow law in tight oil reservoir was revealed. According to the multi-scale flow characteristics in tight oil reservoirs, the flow field structure formed by multi-stage fractured horizontal well was divided into five regions which included the horizontal wellbore region, strong and weak reconstruction region, matrix utilization region and undeveloped region, and the mathematical model of multi-region coupling nonlinear flow was established to characterize the multi-scale flow. According to the affected regions of the dynamic supply boundary, the development process was divided into horizontal wellbore region, reconstruction region coupling stage and horizontal wellbore region, reconstruction region and matrix utilization region coupling stage, and the calculation equations of production in various development stages were derived. The expansion law of dynamic supply boundary and the decline law of production rate in tight reservoir were revealed based on the iterative solution of steady-state sequential replacement. The influences of threshold pressure gradient, stress sensitivity characteristics,etc on the cumulative production were clarified, which provided theoretical basis of efficient development in tight oil reservoirs. The natural energy development case was simulated with the actual parameters of tight reservoir in Ordos Basin for 2 000 d. The results show that the threshold pressure gradient and stress sensitivity have a significant impact on tight oil reservoirs. The stress sensitivity characteristics in the reconstruction region play an important role in the recovery affected, whose influence range is about three times greater than that in the matrix region. With the actual parameters, the reasonable horizontal well length is 2 000-3 000 m, the reasonable fracture half-length is 200-250 m and the reasonable drawdown pressure of the target block is 7-9 MPa.更多还原