Coupling Multiphase Hydrodynamic and NMR Pore-Scale Modeling for Advanced Characterization of Saturated Rocks
- N. Evseev (Schlumberger Moscow Research) | O. Dinariev (Schlumberger Moscow Research) | M. Hurlimann (Schlumberger Doll Research) | S. Safonov (Schlumberger Moscow Research)
- Document ID
- Society of Petrophysicists and Well-Log Analysts
- Publication Date
- February 2015
- Document Type
- Journal Paper
- 32 - 44
- 2015. Society of Petrophysicists & Well Log Analysts
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- 172 since 2007
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We use the novel method of density functional hydrodynamics (DFH) to model complex multiphase scenarios occurring in natural cores on a pore scale. Such scenarios may be extremely diverse, ranging from those inherent in RCA and SCAL measurements, and to much more complex processes relevant to chemical EOR. We perform the numerical simulation of several multiphase flow scenarios by means of the direct hydrodynamic (DHD) simulator, which is a numerical code containing implementation of DFH. We have previously demonstrated some of the capabilities of our numerical tool, DHD, for simulation of multiphase flow previously. Now we focus on a combination of two different methods for characterization of a multiphase system in pores.
The first method comes from hydrodynamic and thermodynamic description obtained through DHD simulation. The second method emerges from numerical modeling of NMR response corresponding to T2 relaxation and pulsed gradient spin-echo (PGSE) experiments, which are routinely conducted not only in laboratory, but also downhole using NMR logging tools. We model the NMR response by solving numerically the generalized Bloch- Torrey equations containing relaxation, diffusion and magnetization transport terms. The equations are subject to boundary conditions describing surface relaxation. The NMR description we use enables performing modeling of T2 relaxation and PGSE experiments, and their combination. The numerical NMR solver is also implemented within the DHD simulator. This facilitates application of NMR modeling (i.e., makes it automatic) to digitized cores with multiphase saturation, whose state has previously been described and simulated in the frame of the DFH. Such close coupling of two characterization methods different by nature is extremely important and brings an opportunity for improvement of NMR response interpretation techniques, which suffer from the inverse and ill-posed nature of the fluids characterization problem.
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