During the operation of commingled production wells, inter-layer interference is a key factor affecting the recovery rate and flooding extraction efficiency. This study proposes a well deliverability equation that is characterized by a multi-parameter coupled inter-layer interference coefficient, which is applied to quantify the commingled production wells in a multi-layer reservoir. This study used principal component analysis (PCA) to study the combined effects of correlation parameters for inter-layer interference. The results show that the starting pressure gradient and the crude oil viscosity contrast have the most significant impact on inter-layer interference. Changes in these two parameters directly enhance the heterogeneity between different oil layers, thereby intensifying inter-layer interference. Additionally, the positive correlation between permeability and permeability contrast also highlights the contribution of physical property differences in the oil layers to the interference. The sensitivity analysis shows the main influencing factors of inter-layer interference in commingled production wells. providing references for subsequent improvements and optimization of the exploitation schemes and adjustments in reservoir management measures. The results not only enhance the understanding of the mechanisms of inter-layer interference in the exploitation of multi-layer oil reservoirs but also provide scientific evidence and technical support for oilfield development.

To solve the development problems caused by the geological characteristics of heterogeneous sandstone reservoirs, such as uneven interlayer exploitation, a method for improving uneven interlayer exploitation differences by applying interlayer injection–production coupling technology is proposed. A physical model of interlayer injection–production coupling is elaborated in detail, and its mechanism of enhancing oil recovery is analyzed. The reservoir physical property parameters are measured, and a productivity numerical model for the two-phase flow of oil–water was established based on measurement results. Then, the effectiveness of interlayer injection–production coupling was evaluated. The results showed that the mechanism of interlayer injection–production coupling can be summarized as reservoir elastic energy adjustment and reservoir flow field reconstruction, based on the established physical model. The application of interlayer injection–production coupling technology can significantly improve the interlayer exploitation differences in strongly heterogeneous sandstone reservoirs. The injection rate, liquid production rate, half-period ratio, and coupling period all have a significant influence on the interlayer injection–production coupling effect. Specifically, for the J1 well group, the injection rate and liquid production rate can be appropriately increased by a factor of 2 and 1.5, and corresponding oil recovery will increase by 6.4% and 5%. Meanwhile, when the half-period ratio increases to 3:1, the oil recovery will increase by 7.08%. Therefore, during the design of the interlayer injection–production coupling scheme, the injection rate and liquid production rate can be appropriately increased, the injection time should be increased for the under-exploitation layer, and the optimal coupling period should be selected based on the characteristics of the oilfield.