考虑滑脱效应的低渗低压气藏的气井产能方程

考虑了气体在低渗低压气藏中的滑脱效应，定义了考虑滑脱效应的滑脱表皮系数（S_滑脱），建立了形式简洁的气井产能方程。S_滑脱介于-1～0之间，即滑脱效应可以增加气井产能。在已知其他参数的条件下，只需计算出S_滑脱就可以确定出存在滑脱效应的气井产能。由于实际气藏往往会表现出其他非线性渗流特征（如启动压力梯度效应和高速非达西效应），因此实际应用时还需要考虑这些因素。现场实例分析表明：对于存在滑脱效应的低渗气藏气井而言，用该新的产能公式计算出的产能大于用常规产能公式计算出的产能，且与实际产能比较吻合，表明了公式的正确性和适用性。

A new deliverability equation considering slippage effect for gas reservoirs with low permeability and low pressure

Considering the effect of slippage effect on the deliverability of low permeability and low pressure gas reservoirs, a slippage skin factor is defined, and thus the concise deliverability equation considering the slippage effect is established. The slippage effect with skin factor ranging from 1 to 0 can improve the deliverability of gas wells. According to other known parameters, the deliverability of gas wells with slippage effect can be obtained only by slippage skin factor. Actual gas reservoirs always present many nonlinear flow characteristics, such as threshold pressure gradient and high velocity non Darcy flow, so these elements must be taken into account in actual cases. It is shown by actual examples that for the gas reservoirs with slippage effect, the deliverability calculated by the new deliverability equation is larger than that calculated by conventional deliverability equation, and agrees well with actual deliverability, which proves the correctness and applicability of this new formula.