Plugging agents add value to EOR operation

Adding chemical oil-displacement agents to steam flooding treatment has recently become a common Enhanced Oil Recovery (EOR) method. However, the significant reservoir heterogeneity in Xinjiang heavy oil reservoir has resulted in steam channeling, which may allow the injected chemicals to move to the producing well while bypassing the pay zone with high oil saturation. This has led to poor utilization efficiency and sweep efficiency of the chemicals. A new technique uses plugging agents to block the steam channels before injecting the oil-displacement chemicals. This helps to expand the sweep range of chemicals to the untouched area, improving recovery. After promising laboratory results were obtained, the method was applied to the 314 wells in regions 9(4) and 9(5) of Xinjiang field. Of these, 213 experienced increased oil production, totaling about 247,600 bbl (36,650 metric tons) over 7 yr, as well as an average reduction of more than 3% in watercut.