Nano-pores in unconventional reservoirs can cause deviations from Darcy's law where permeability becomes a strong function of pore size and pore pressure. As pores become smaller, the interaction of gas molecules with the pore walls becomes increasingly dominant compared to interactions between gas molecules. This increases gas mobility leading permeabilities measured in the lab not to be accurate at reservoir conditions. Thus, corrections to Darcy flow may be needed when analyzing well production behavior. This paper demonstrates a novel workflow for modeling the impact of non-Darcy flow regimes (i.e., gas slippage, transition flow and Knudsen diffusion) from pore scale characterization to reservoir scale flow simulation. A stochastic approach is used for uncertainty assessment on non-Darcy corrections needed for methane mobility as pore pressure depletes based on reservoir properties, pore sizes, rock compressibility and compaction. Flow simulations are conducted for a range of scenarios to test the impact on the recovery of an unconventional well. Study is conducted using a commercial simulator since workflow modifies the input to the simulator and does not need a new code development. The workflow is demonstrated using field data and shows that non-Darcy flow regimes can have significant impact by increasing gas mobility at low pore pressures near hydraulic fractures. For the field under study, ignoring non-Darcy flow risks up to 20% lower estimations in cumulative gas production under certain scenarios.

中文翻译：

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非达西流对非常规井动态影响的风险评估。

非常规储层中的纳米孔隙可能会导致达西定律的偏差，其中渗透率成为孔径和孔隙压力的强函数。随着孔隙变得更小，与气体分子之间的相互作用相比，气体分子与孔壁的相互作用变得越来越占主导地位。这增加了气体流动性，导致实验室测量的渗透率在储层条件下不准确。因此，在分析油井生产行为时，可能需要对达西流进行修正。本文展示了一种新颖的工作流程，用于对从孔隙尺度表征到储层尺度流动模拟的非达西流态（即气体滑移、过渡流和克努森扩散）的影响进行建模。随机方法用于根据储层特性、孔径、岩石压缩性和压实度，对孔隙压力消耗时甲烷迁移率所需的非达西校正进行不确定性评估。针对一系列场景进行流动模拟，以测试对非常规井采收率的影响。研究是使用商业模拟器进行的，因为工作流程修改了模拟器的输入并且不需要新的代码开发。该工作流程使用现场数据进行了演示，并表明非达西流态可以通过增加水力裂缝附近低孔隙压力下的气体流动性来产生重大影响。对于所研究的油田，忽略非达西流风险，在某些情况下累积天然气产量的估计值会降低 20%。