稠油油藏气体辅助蒸汽驱参数优化研究OA

This study focuses on the challenges of low steam utilization efficiency and inadequate parameter optimization encountered during the late phase of steam flooding development in heavy oil reservoirs.Taking Block B of Y Oilfield as an example,this paper discusses the feasibility and effectiveness of gas-assisted steam flooding.A comparative numerical simulation was conducted for CO2-assisted steam flooding,N2-assisted steam flooding and CO2+N2 dual-phase assisted steam flooding to identify the optimal gas-assisted steam flooding method.On this basis,key factors such as the steam/gas injection rate,steam quality,and other related parameters were further optimized,and the optimal parameter combination was obtained through orthogonal experiments.The results indicate that among the three gas-assisted steam flooding methods,CO2-assisted steam flooding exhibits the best performance.The optimal parameter combination was as follows:CO2 injection volume of 0.25 PV,gas injection rate of 2.25×103 m3/d,steam injection rate of 150 m3/d,steam dryness factor of 80%,and the ratio of CO2 to steam mass is 15.Under this optimized conditions,the oil production and recovery factor of the block increased by 2.84×104 t and 9.37 percentage points,respectively,compared with pure steam flooding,demonstrating a significant improvement in production performance.