Effects of injection pipe shoe setting depth on steam injection performance

Key words:  heavy oil  steam soaking  tubing string  variable mass flow  steam injection performance

Abstract:

Two different shoe setting modes of locating at the top(A) and at the bottom(B) of well completion intervals for steam injection pipe were introduced. Energy conservation relationship in well completion intervals was developed by analyzing variable mass flow characteristic of the steam. Time function was modified considering the influence of reservoir heating area enlarging with the injecting time prolonging on radial heat conduction. The steam injection performances were calculated on the basis of the reservoir parameters of Shanjiasi reservoir in Shengli Oilfield, The results show that the steam parameters variation in well completion intervals is larger than that of wellbore because the cross-section area increases suddenly when steam flows through well completion intervals and the flow of steam is variable mass flow, and the separation effect and gravity effect of steam and liquid increase for mode A. The pressure and steam quality difference along well completion intervals for mode A are larger than those of mode B, and the variation trends of steam quality for two modes are opposite. Different injection pipe shoe setting depth can be changed periodically to improve steam injection profile of well completion intervals for steam soaking well.