1 / 22

The distillation mechanism in steam displacement of oil

The distillation mechanism in steam displacement of oil. Dan Marchesin and Hans Bruining, . ECMOR X Sept 4-7, 2006. An example of all the pathological problems with conservation laws. Elliptic regions (Not discussed here) Non-Lax shocks (*) and uniqueness

wallis
Download Presentation

The distillation mechanism in steam displacement of oil

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The distillation mechanism in steam displacement of oil Dan Marchesin and Hans Bruining, ECMOR X Sept 4-7, 2006

  2. An example of all the pathological problems with conservation laws • Elliptic regions (Not discussed here) • Non-Lax shocks (*) and uniqueness • Small diffusion is dominating efficiency of process *E. Isaacson. D. Marchesin, and B. Plohr , Transitional waves for conservation laws, SIAM J. Math. Anal. 21, 831-866 (1990) Amsterdam: ECMOR X: Sept. 4-7, 2006: 20 slides

  3. Steam injection Steam injection is commercially applied to recover viscous oils Amsterdam: ECMOR X: Sept. 4-7, 2006: 19 slides

  4. Steam+Vol-oil Sw,Sg,So=0,vov >0 Sw,So,vov = 0 initial Volatile oil bank Initial composition Volatile oil enhanced steam drive • Proposed by Dietz (1979) Amsterdam: ECMOR X: Sept. 4-7, 2006: 18 slides

  5. water dead oil Vol. oil Steamzone cold zone Steam+vol. oil Liq. Vol. oil initial oil Vol. oil vapor Zero oleic phase ES-SAGD (Ian Gates) Co-inject some volatile oil with steam Courtesy: Claes Palmgren Amsterdam: ECMOR X: Sept. 4-7, 2006: 17 slides

  6. Steam+Vol-oil Sw,Sg,So=0,vov >0 Sw,So,vov = 0 initial Volatile oil bank Initial composition Laboratory tests showing the effect of coinjected volatile oil

  7. Contents • Reasons why modeling of this process is complex • Formulation including capillary and diffusion effects • Dodecane, cyclo butane and heptane: Bifurcations depending on boiling points • Importance of diffusion processes • Peak wave and effect on recovery Amsterdam: ECMOR X: Sept. 4-7, 2006: 15 slides

  8. Shock velocity Sw(-) Sg(-) Sw(+) Darcy velocity (+) Water balance Oil balance Energy balance Welge shock condition Missing equation? MOC models complicated due to saddle to saddle connection in shocks (not a Lax shock) Sw,Sg,So=0,vov =0 Sw,So,vov =0 initial Steam Bruining, J., Duijn, C.J. van, "Uniqueness Conditions in a Hyperbolic Model for Oil Recovery by Steamdrive“, Computational Geosciences" No 4, pp 65-98 (2000), “Traveling waves in a finite condensation rate model for steam injection”, ibid. 2006

  9. Steam+Vol-oil Sw,Sg,So=0,vov >0 Sw,So,vov = 0 initial Volatile oil bank Initial composition Simulation gives unrealistic results due to numerical dispersion Sw,Sg,So=0,vov =0 Sw,So,vov >0 initial Steam Volatile oil bank Initial composition Amsterdam: ECMOR X: Sept. 4-7, 2006: 13 slides

  10. Motivation of combined analytical and numerical approach • Simulators overemphasize diffusion/ capillary diffusion; are the solutions realistic? • Are we allowed to disregard diffusion all together? • Does the form of the diffusion e.g. saturation dependence affect the global solution even if it is small? • Existence and uniqueness? We are using empirical relations to describe the convection flow • Possible bifurcations analysis i.e. solutions change behavior if parameters cross critical values (*). • Discovery of new recovery mechanisms * Bruining, J. and Marchesin, D. , Nitrogen and steam injection in a porous medium with water, TIPM (March 2006), 62 (3), 251-281 Amsterdam: ECMOR X: Sept. 4-7, 2006: 12 slides

  11. Steam+Vol-oil Sw,Sg,So=0,vov >0 Sw,So,vov = 0 initial Volatile oil bank Initial composition Model • Injection steam and volatile oil vapor in core Sw=Swc, So=1-Swc • No dissolution of water in the oleic phase. • Volatile oil vapor mixes in all proportions with steam. Liquid volatile oil mixes with “dead” oil. Dead oil only occurs in the oleic phase. • Viscosities depend on T and the composition vov . • No volume effects on mixing • Capillary forces and diffusional effects incorporated • Local thermodynamic equilibrium -> f = c – p + 2

  12. Four conservation laws: water, dead oil, volatile oil, energy • ov(T) volatile oil concentration in oleic phase • gv(T) volatile oil concentration in gaseous phase • uov(T) Darcy velocity volatile oil in oleic phase • ugv(T) Darcy velocity volatile oil in gaseous phase

  13. Formulations of interest • Analytical solution; without capillary and diffusion -> hyperbolic problem (solution discussed here); details in paper submitted to Phys. Rev. E • Numerical solution; with capillary and diffusion (see Figs. 1, 2, 3.); details in paper submitted to Phys. Rev. E • Traveling wave solution in steam condensation zone (formulation presented in paper) * Bruining, J. and Marchesin, D. , Maximal Oil Recovery by simultaneous condensation of alkane and steam, Submitted to Phys Rev E Amsterdam: ECMOR X: Sept. 4-7, 2006: 9 slides

  14. Steam+Vol-oil Sw,Sg,So=0,vov >0 Sw,So,vov = 0 initial Volatile oil bank Initial composition Dodecane coinjected (num. sol.)

  15. Steam+Vol-oil Sw,Sg,So=0,vov >0 Sw,So,vov = 0 initial Volatile oil bank Initial composition Cyclo-butane coinjected (num. sol.)

  16. Steam+Vol-oil Sw,Sg,So=0,vov >0 Sw,So,vov = 0 initial Volatile oil bank Initial composition Comparison numerical (left) and analytical solution; Medium boiling (heptane) volatile oil Saturations 0  S 1., vov: fraction of volatile oil in the oleic phase.

  17. Numerical (left) and analytical solution, Medium boiling volatile oil initially present Saturations 0  S 1., vov: fraction of volatile oil in the oleic phase. Amsterdam: ECMOR X: Sept. 4-7, 2006: 5 slides

  18. Medium volatile oil slug injection problem. Rescaled temperature 0  T  1., vov is fraction of volatile oil in the oleic phase. Amsterdam: ECMOR X: Sept. 4-7, 2006: 4 slides

  19. Blow up of previous plot Structure of the transition zone consisting of a 3- and a 2-phase part. Rescaled temperature 0  T  1. Volatile oil peak indicated by vov between hot steam zone and cold liquid zone . Amsterdam: ECMOR X: Sept. 4-7, 2006: 3 slides

  20. Stability of diffusion bank First 7 time intervals: volatile oil is coinjected with the steam. Second 7 time intervals: pure steam injection. volatile oil peak is essentially preserved ensuring high recovery of oil Amsterdam: ECMOR X: Sept. 4-7, 2006: 2 slides

  21. Conclusions • During steam injection with co-injection of volatile oil a volatile oil peak is formed between the steam zone and the liquid zone • The volatile oil peak is a component of a traveling wave solution; this is a new type of wave • After turning to pure steam injection the volatile oil peak remains more or less unchanged • A steady volatile oil peak is capable of reducing the residual oil during steam drive and hence enhances the oil recovery • These conclusions must still be rigorously validated by solving the traveling wave problem Amsterdam: ECMOR X: Sept. 4-7, 2006: last slide

  22. Conclusions • Finite volume methods can give erroneous results when describing non-Lax shocks • Only medium range boiling volatile oils added to the steam help to improve the oil recovery; low range boiling oils form a 3-ph zone beyond the SCF. High range boiling oils stay behind. • Molecular diffusion plays an important role in determining the efficiency of volatile oil enhanced steam drive recovery. • (un) stable nodal points

More Related