Chapter 3
generate a contrast based on the relaxation time difference between oil and water,
one solution is to perform a T1 weighted spin density profile by stacking a certain
number of scans repeated after a time t∏. Then, the amplitude at a given position
z is given by:
Aτ (z) = Λ[1 - X φi ∞s>(-tv / Tu )] [3.33]
Here φ,∙ is the volume fraction for component /. tw = tR- tε≈ tR is the waiting
time. For water-in-oil emulsions, Eq. [3.19] can be written as:
ʌ(z) = 4β[1 -Φoil Q^>{γ4-φwater exp(-^-)-φemul exp(-⅛ [3.34]
ɪl,o// j^ !,water j^!,emul
Here subscripts oil, water and emul correspond to continuous oil, bulk water
and water droplets, respectively.
Figure 3.7 shows scheme of 1-D profile measurement for layered mixture of
water and diluted bitumen. The left photograph shows layered mixture of water
and diluted bitumen. The right part of the figure shows 1-D profile result of layered
mixture. The x axis is signal amplitude of the sample, and the y axis position is the
position measured from the middle of the sample. Signal amplitudes in oil layer
and water layer have obvious difference. It is easy to find oil/ water interface from
the step change of signal amplitude.
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