Practice and understanding of water huff-n-puff in shale oil of Subei Basin
The production of BG shale oil Block of Jinhu Sag of Subei Basin declines rapidly after fracturing,showing poor development efficiency.Enhancing the estimated ultimate reserves(EUR)of individual wells during later depletion stages is crucial for profitable development.While CO2 huff-n-puff is a common stimulation technique,its high costs and variable effectiveness have limited its widespread adoption.Based on the geological characteristics of BG block,we carried out research on the mechanism of shale oil stimulation by water huff-n-puff by using core NMR,SEM,well test analysis and other methods,and clarified that water huff-n-puff can greatly develop the oil in 1～100 nm pores in imbibition process and improve the porosity and permeability conditions.Given the Subei Basin shale oil's notable hydrophilicity,rich oil content,and extensive fracture network,water huff-n-puff technology was proposed and field-tested.Up to now,the cumulative oil increase of the two test wells is more than 7 600 tons,which shows good application prospects and economic benefits.And it has guiding significance for the low-cost and efficient production stimulation in the shale oil development in Subei Basin.
NETL
NSTL
万方数据
