Study On The Law Of Steam Chamber Expansion And Production Capacity Prediction In Steam-Assisted-Gravity-Drainage Process

China is one of the major heavy oil producing countries in the word and has abundant heavy oil reservoirs.In order to meet China's rapidly increasing consumer demand of oil,the development and utilization of heavy oil is gradually gaining more attention.SAGD(steam-assisted-gravity-drainage)has been proved to be a mature thermal recovery technology and used for broad-scale commercial mining.The steam chamber formation and expansion is the key in SAGD process,and therefore,it is necessary to explore the effect of the law of steam chamber expansion on SAGD production.In this paper,a new heterogeneous reservoir equation is proposed by considering the linear relationship of oil saturation and temperature based on Butler's classical model,the variation of steam chamber height with time is explored,and the sensitivity effect of reservoir and fluid property parameters on the time of steam chamber expansion is analyzed.A novel heterogeneous reservoir oil production model is developed by optimizing the oil permeability of Butler's model.The accuracy has been verified by comparing the results calculated by new model with field data.The impact of reservoir and fluid property parameters on oil production has been explored to improve the SAGD efficiency.The heat transfer mechanism in steam chamber edge is an important factor in SAGD process.Two models are established to explore the effect of connate water and condensate on heat transfer process at the steam chamber boundary respectively.The accuracy of models has been proven by comparing the calculation results with field data,such as temperature profile,pressure profile,conduction and convection heat flux distribution and apparent thermal diffusivity et al.In this pater,the components of conduction and convection beyond the steam chamber boundary are inspected,and the influence of heat transfer on oil production by considering convection is revealed to improve the SAGD performance by strengthening the heat transfer process.This paper explores the laws of expansion,heat transfer,oil production at the steam chamber edge by developing mathematical model and date comparison verification,and provides the theoretical base for further optimizing the steam chamber expansion and enhancing the SAGD efficiency.