Application and Effectiveness of Anionic Foaming Agents in Gas Channeling Control in a Block of Tarim Oilfield

The CⅢ oil formation in a certain block of the Tarim Oilfieldhas entered the late stage of high water-cut development. Gas injection, as one of the key technologies for enhancing oil recovery, has been widely applied in this block. However, after multiple rounds of gas injection, significant gas channeling pathways have formed within the injection-production well groups, severely impacting the effectiveness of oil production enhancement. There is an urgent need to conduct research on gas channeling control. Given the high-temperature and high-salinity geological characteristics of the CⅢ formation in the block, this study selected a fully anionic foaming agent as the primary agent for gas channeling control and conducted systematic laboratory evaluations of its performance. Experimental results show that when the mass concentration of the fully anionic foaming agent is 0.1%, its foaming ratio exceeds 450%, the liquid drainage half-life is greater than 30 min, and the foam decay half-life exceeds 850 min. The foaming performance remains largely unaffected before and after adsorption on quartz sand surfaces. In cores with gas permeability of 80 mD and 180 mD, the foam resistance factors are greater than 65 and 125, respectively, demonstrating excellent thermal stability. Field application results indicate that the technology was successfully implemented in one well group in the CⅢ formation of a certain block in the Tarim Oilfield. After gas channeling control, the oil production of six oil wells in the well group significantly increased, the gas-oil ratio decreased noticeably, and the cumulative incremental oil production reached 7,381 tons, achieving excellent development results. This study highlights the effectiveness of the fully anionic foaming agent in controlling gas channeling and improving oil recovery in high-temperature, high-salinity reservoirs, providing valuable insights for similar oilfield development projects.