Commingled energy replenishment and carbon dioxide energy replenishment differential technology for enhanced oil recovery in shale oil horizontal wells
The shale oil horizontal wells in Qingcheng Oilfield are developed using high volume hydraulic fracturing with quasi natural energy,but the overall production decline is severe.Although some wells in the matured oil area have long horizontal sections and large controlled reserves,due to insufficient initial transformation,the cumulative oil production and recovery rate of single wells are low.In addition,the recovery rate of production by acidizing and unplugging in old wells has been decreasing year by year,and insufficient formation energy is the main factor causing the decline in production.In order to achieve the orderly succession and utilization of formation energy in shale oil development,a strategy of combination of repeated fracturing and produced water commingled energy replenishment in horizontal wells has been proposed.By prioritizing the use of mature technology for reinjection of produced water,the affected volume and oil displacement efficiency are improved,and with a focus on indoor research on carbon dioxide energy replenishment and horizontal well repeated fracturing,the differentiated design of different process parameters for different wells is clarified.By conducting field experiments such as commingled energy replenishment and carbon dioxide energy replenishment tests on horizontal well produced water for 4 wells,as well as repeated fracturing tests for 3 wells to improve oil recovery,the single well fluid volume has been effectively increased by 4 to 5 times,and the formation energy has been increased by about 70%.This technology provides optional methods for achieving efficient recovery of shale oil horizontal wells with different oil wells and extraction methods.
万方数据
维普
