1 / 9

Unsteady State Relative Permeability Measurement in Core Plugs

This article discusses the method of measuring relative permeability in core plugs under unsteady-state conditions. It covers stages of saturation, production rates, imbibition ratios, analysis procedures, and assumptions involved. Hysteresis effects and plotting techniques are also explored.

bstephen
Download Presentation

Unsteady State Relative Permeability Measurement in Core Plugs

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. Laboratory MeasurementofRelative Permeability

  2. Rel. Perm. - Unsteady State • Unsteady State Method for relative permeability provides • Relative permeability ratio (kr,nonwet/kr,wet) as a function of wetting phase saturation (Swet) • Irreducible wetting phase saturation (drainage) • Residual nonwetting phase saturation (imbibition)

  3. Rel. Perm. - Unsteady State Saturation in Core Plug Production Rates • Imbibition Relative Permeability Ratio Function • Stage 1: Preparation for drainage • core saturated with wetting phase • Stage 2: Irreducible wetting phase (drainage) • inject non-wetting phase until steady state, measure saturation • no wetting phase will be produced after steady state

  4. Rel. Perm. - Unsteady State Saturation in Core Plug Production Rates • Imbibition Relative Permeability Ratio Function • Stages 3-6: Inject wetting phase • Stage 3 (A) Wetting phase has not yet reached outflow face • only nonwetting phase produced at outflow face • Stage 4 (B) Wetting phase just reaches outflow face, called breakthrough • wetting phase will be produced at outflow face

  5. Rel. Perm. - Unsteady State Saturation in Core Plug Production Rates • Imbibition Relative Permeability Ratio Function • Stages 3-6: Inject wetting phase • Stage 5 (C) As injection of wetting phase continues, production of nonwetting phase decreases (unsteady state) • Important to take many data points during this decrease • cummulative nonwetting phase produced • production rate for both phases

  6. Rel. Perm. - Unsteady State Saturation in Core Plug Production Rates • Imbibition Relative Permeability Ratio Function • Stages 3-6: Inject wetting phase • Stage 6 (D) Eventually, no more nonwetting phase is produced, allowing residual nonwetting phase saturation to be determined

  7. Rel. Perm. - Unsteady State • Analysis Procedure • Assumptions • immiscible displacement • incompressible fluids • linear, 1-D flow • capillary pressure neglected • Determination of average saturation • cumulative nonwetting phase production • Determination of relative permeability ratio from fractional flow • fwet = qwet/qtotal ; where qtotal = qwet + qnonwet • production rate measured at outflow face

  8. Rel. Perm. - Unsteady State • Analysis Procedure • Assumptions • immiscible displacement • incompressible fluids • linear, 1-D flow • capillary pressure neglected • Determination of average saturation • cumulative nonwetting phase production • Determination of relative permeability ratio from fractional flow • fwet = qwet/qtotal ; where qtotal = qwet + qnonwet • production rate measured at outflow face

  9. Rel. Perm. - Unsteady State • Relative Permeability Ratio usually plotted semi-log • hysteresis due to saturation process (drainage, imbibition)

More Related