Estimation of Permeability with Seismic “I really did mean ... of Permeability with Seismic “I really did mean to say ... note: volume fraction ... Estimation of Permeability with Seismic “I really did mean to say

Download Estimation of Permeability with Seismic “I really did mean ...  of Permeability with Seismic “I really did mean to say ... note: volume fraction ... Estimation of Permeability with Seismic “I really did mean to say

Post on 05-Apr-2018

221 views

Category:

Documents

7 download

Embed Size (px)

TRANSCRIPT

  • Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Michael Glinsky

    1Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Outline

    rock physics model supporting measurements (log and core) numerical rock assembly model model based seismic inversion & practical detectability conclusions

    2Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Floating grain model - the link of deposition physics to grain scale properties, permeability

    Load-Supporting

    Floating

    Abundance of potential floating grains in the system is due to two factors overall abundance of silt/mud-sized particles (related to nature of clastic input and system-scale proximal vs distal position) local variation due to depositional processes (e.g. rapid fallout vs traction)

    3Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Capture Ratio = 1 (1/1.5) = 33% ie 1/3 of small grains are captured in to the load bearing matrix of the rock. The capture ratio will depend on the

    geometries of the original grains.

    Capture ratio is another key concept

    At a constant Effective Stress - For every 3 small grains, 1 becomes part of matrix and 2 will float

    porosity (%) = -1.5*float(%) + B (B is a constant for a particular constant Pe)

    Bimodal grain sizes (big and small)

    porosity in % = -1.54 * float in % - 88% * ( 1 exp( - Pe / 800 psi ) ) + 110% +- 0.2%

    4Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Petrophysical evidence for the floating grain model

    Vp (ft/s)

    dens

    ity (g

    m/c

    c)

    well #2

    well #5

    well #6

    well #3

    well #4

    well #1

    5Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Relationship between size distribution and floating grain fraction

    well #1well #2well #3

    well #1well #2well #3

    6Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Good regression found between the permeability, porosity, and floating grains

    10% 30%porosity0

    3.5

    log(

    perm

    in m

    D)

    10% 30%log(perm in mD)0

    3.5

    log(

    pred

    icte

    d pe

    rm)

    well #1well #2well #3

    log( perm in mD) = 0.198 * porosity in % - 0.325 * floating in % - 1.76 + - 0.37x / 2.3

    well #1well #2well #3

    7Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Acoustic resonance measurements on well #2 core confirm trend seen in logs

    2

    2.05

    2.1

    2.15

    2.2

    2.25

    2.3

    2.35

    2.4

    2000 2500 3000 3500 4000

    vp (m/s)

    den

    sity

    (g

    m/

    cc)

    6% float0% floatmeasurment6% float

    0% float moderate sorting

    moderately poor

    poor

    8Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    No change in shear velocity as seen on logs and predicted by theory

    1800

    2000

    2200

    2400

    3000 3200 3400 3600 3800

    vp (m/s)

    vs

    (m/

    s)

    0% float

    6% float

    Ps correctedaverage

    6% float

    0% float

    moderate sorting

    moderately poor

    poor

    9Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Floating grains seen in CAT scan and SEM of well #2

    sample #3, moderate sorting, 300 mD, 24%

    50 micron500 micron

    #1, poor, 10 mD, 20%500 micron

    #2, moderately poor, 100 mD, 22%500 micron

    5 mm

    10Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Guide to AVO interpretation

    Increasing NG0% to 100%

    Brine to Oil

    Decreasing Float6% to 0%Increasing perm1 mD to 1000 mD

    Decreasing Effective Stress1000 psi

    Dimming AVO

    Brightening AVO

    good

    bad

    11Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Numerical rocks give important understanding of floating grain model

    Create sphere packings (two size) representative of unconsolidated sediment through cooperative rearrangement algorithm

    Quantify the number of loose grains in packings Understand capture fraction

    12Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Mono-dispersed packing validation

    Single grain size Comparison with Finney packing Quality checks:

    Porosity 36.3% Finney v. 36.2% simulation

    Percent of loose grains 1.8% Finney v. 1.6% simulation

    Radial distribution function

    13Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Floating grain fraction & capture ratio demonstrated

    Little dependence on RR5 vol% 40 vol%

    RR = radius ratio

    float

    ing

    grai

    n pe

    rcen

    t

    critical point

    (small grain load support)

    (large grain load support)

    capture fraction0

    1/3

    2/3

    1

    Thermodynamics of random packing, Physics Today (June 2007)

    14Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Phase diagram for random packing of binary mixture of spheres

    (large grain load support, small grains float)

    (small grain load support)

    (large grain load support, small grains part of matrix)

    RRc VFc

    note: volume fraction dominates over radius ratio critical point

    Statistical mechanics of dense granular media, Coniglio et al., J. Cond. Matter 17, S2557 (2005).

    Rc 4VFc 0.45

    15Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Critical scaling for radius ratio critical point (RRc)

    y =

    0.0103x2.2609

    0

    0.01

    0.02

    0.03

    0.04

    0.05

    0.06

    0.07

    0.08

    0.09

    -1 0 1 2 3

    RRc-RR

    fmax -

    f(p

    eak)

    fit data

    data

    Power (fit data)

    y =

    0.0102x2.1708

    0

    0.01

    0.02

    0.03

    0.04

    0.05

    0.06

    0.07

    0.08

    -1 0 1 2 3

    RRc-RR

    Dp

    oro

    sity

    (max)

    - D

    po

    rosi

    ty(p

    eak)

    fit data

    data

    Power (fit data)

    y =

    0.1467x1.8419

    0

    0.1

    0.2

    0.3

    0.4

    0.5

    0.6

    0.7

    0.8

    0.9

    1

    0 0.5 1 1.5 2 2.5 3

    RRc - RR

    CF0

    = C

    F(V

    F=

    0)

    fit datadataPower (fit data)

    capture fraction @ volume fraction = 0

    peak decrease in porosity

    peak floating fraction

    16Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Critical scaling for volume fraction critical point (VFc)

    y = 2.4516x1.31

    0.00

    0.10

    0.20

    0.30

    0.40

    0.50

    0.60

    0.70

    0.80

    0.90

    1.00

    -0.10 0.00 0.10 0.20 0.30 0.40 0.50

    VFc-VF

    CFmax*(CFmax-CF)/(CFmax-CF0)

    fit dataRR=1.5RR=2RR=3RR=4Power (fit data)

    capture fraction

    17Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Permeability can be simulated given 3D rock matrix from CAT

    small capillary pressure large capillary pressure

    18Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Implementation of floating grain model in DELIVERY

    = A+B vp+Cflt + (from numerical inversion of above, using clusters)

    vp= Ap +Bpd + Cp LFIV + Dp flt+p (inverted from this regression, direct from log data and clusters)

    =A+Bd+C flt+ , with d(1-exp(-eff/P0))C=-1/(1-fc), fc is capture fraction

    Vs= As+Bs vp+ s - direct from log data

    19Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Layer based model derived from blocking for well #2

    20Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Multiple stack inversion Bayesian inversion is used

    before inversion, ignore seismicafter inversion, honour

    seismic to within noise level

    near far

    21Monday, 25 January 2010

  • CSIRO. Estimation of Permeability with Seismic I really did mean to say permeability not porosity

    Floating grain fraction and porosity are determined by seismic

    time of layer boundary - seismic determines N/G - seismic does not determine

    float fraction & porosity - seismic determines ==> permeability