致密储层气体滑脱效应研究

针对气体滑脱效应产生机理认识不清的问题，通过不同类型气体测试贝雷砂岩和页岩岩样的渗透率实验，提出产生气体滑脱效应的原因为不同类型流体通过储层孔喉的下限不同和流体-固体界面张力不同导致界面处流体存在流速差异，并且气体滑脱系数与岩石类型和气体种类有关，压力、温度主要影响气体的高压物性。同时，基于达西公式和拟压力函数建立考虑滑脱效应影响的产气量方程，分析认为在常规气井产能评价中可以忽略滑脱效应对气井产能的影响，仅在低压、低渗储层中予以考虑。

Research on Gas Slippage Effect in Tight Reservoir

In view of the unclear understanding of mechanism of gas slippage effect, the new recognition of the gas slippage effect was put forward through different types of gas experiments which are used for testing the permeability of Berea sandstone and shale samples. It is proposed that diversity in lower limits of types of fluid through the reservoir pore throat and fluid-solid interface tension leads to differences in fluid velocity at the interface.Besides, the gas slippage coefficient is related to rock type and gas type while pressure and temperature mainly affect the high-pressure physical properties of the gas. Meanwhile, a gas production equation considering slippage effect was established, based on Darcy formula and pseudopressure function. It is concluded that the influence of slippage effect on gas well productivity can be ignored in conventional gas well productivity evaluation and only considered in low pressure and low permeability reservoirs.