Commingled production has been widely used as an efficient production method in gas field. However, the interlayer interference of gas flow seriously restricts the improvement of gas recovery. Presently, there are several investigations on commingled production characteristics of multi-pressure system gas reservoirs, but no corresponding improved production methods have been proposed. In this study, commingled production characteristics were studied by conducting simultaneous production (simultaneously opening all gas layers for production) simulation experiments. Subsequently, the mechanism of eliminating interlayer interference was revealed by conducting progressive production (progressively opening each gas layer for production) simulation experiments. Then, the effect of interlayer pressure difference on the gas recovery was studied to evaluate the improvement effect of gas recovery. Finally, the effects of initial temperature and pressure on gas recovery were explored to judge the applicability of the progressive production. All experiments were conducted with full-diameter cores of tight sandstone under conditions of temperature, pressure and gas–water saturation similar to those of the actual reservoirs. Experimental results showed that the gas produced by the high-pressure layer may flow back to the low-pressure layer through the interconnected pipeline at outlet end, thereby inhibiting the production capacity of the low-pressure layer and the gas recovery during commingled production. The progressive production method effectively avoids the occurrence of backflow, reduces the effect of interlayer interference, balances the production contribution ratio of different layers and improves the total gas production and recovery efficiency. The progressive production can improve the gas recovery of all gas layers; however, the improvement effect on the low-pressure layer is much better than on the high-pressure layer. The gas recovery from the low-pressure layer to the high-pressure layer increased by 2.62%, 2.23%, 1.41% and 1.23%, respectively. The increase in interlayer pressure difference can intensify interlayer interference and reduce the gas recovery of both simultaneous and progressive production. However, the greater the interlayer pressure difference (2, 3 and 4 MPa), the better the improvement effect of the progressive production in gas recovery (2.04%, 2.66% and 3.61%). The progressive production is effective for multi-pressure system with different initial temperatures and pressures.

混合生产已被广泛用作气田中的一种有效生产方法。但是，气流的层间干扰严重地限制了气体回收率的提高。目前，对多压力系统气藏的混合生产特征进行了一些研究，但尚未提出相应的改进生产方法。在这项研究中，通过同时进行生产（同时打开所有要生产的气体层）模拟实验来研究混合生产特性。随后，通过进行渐进式生产（逐步打开每个要生产的气体层）模拟实验，揭示了消除层间干扰的机理。然后，研究层间压差对气体采收率的影响，以评价气体采收率的改善效果。最后，探讨了初始温度和压力对天然气采收率的影响，以判断逐步生产的适用性。所有实验都是在与实际储层相似的温度，压力和气水饱和度条件下，用致密砂岩的全直径岩心进行的。实验结果表明，高压层产生的气体可能会通过出口端的互连管道流回低压层，从而抑制了低压层的生产能力以及混合生产过程中的气体回收。渐进式生产方法有效地避免了回流的发生，减少了层间干扰的影响，平衡了不同层的产油比，提高了总产气量和采收率。逐步生产可以改善所有气体层的气体回收率。但是，对低压层的改善效果比对高压层的改善效果好得多。从低压层到高压层的气体回收率分别增加了2.62％，2.23％，1.41％和1.23％。层间压力差的增加会加剧层间干扰，并降低同时生产和逐步生产的气体回收率。但是，层间压力差（2、3和4MPa）越大，逐步采气对气体采收率的改善效果越好（2.04％，2.66％和3.61％）。