Monthly Luncheon Meeting
March 21 2019
PanAm Building- Suite 1600
601 Poydras St,
New Orleans, LA 70130
11:30 – 1:00 pm
Register and pay online or pay cash/check at the door.
RSVP: Elizabeth Tanis (Elizabeth.Tanis@shell.com) Cost - $25
Improved Interpretation of Electrical Resistivity
Measurements in Mixed-Wet Rocks:
An Experimental Core-Scale Application and
Presented By: Chelsea Newgord - The University of Texas at Austin, Petroleum Engineering Master's Student
Interpretation of electrical
resistivity measurements for assessing hydrocarbon saturation in mixed-wet and
hydrocarbon-wet rocks often requires extensive recalibrations of resistivity
models. In these conventional resistivity models, the impact of wettability is
not reliably incorporated. Recently, we analytically derived a new resistivity
model that incorporates parameters to account for wettability and complexity of
pore structure. This new model requires experimental verification to enhance
its applicability in core- and log-scale domains. In this paper we (1)
experimentally quantify the influence of wettability on electrical resistivity
measurements, (2) improved and verified our analytically derived resistivity
model in rocks with different levels of wettability at different water
saturations, and (3) demonstrated the physical meaning of the parameters
related to wettability in the resistivity model. We altered the wettability of
selected core samples from the same rock type. To prepare the core samples as
mixed-wet, a surfactant solution was injected into the samples and then they
were aged in decane. These approaches created a range of wettability states in
the samples. To quantify the altered wettability of the samples, we used the
combined USBM and Amott-Harvey method along with sessile drop contact angle
measurements. Next, we used a centrifuge to vary the water saturation in the
core samples. We then measured the electrical resistivity of each sample.
Finally, we improved the recently introduced resistivity model and compared the
estimates of resistivity index from the improved model against the
experimentally measured resistivity indices.
We successfully verified the
reliability of the improved resistivity model for mixed-wet carbonate core
samples. The wettability of the core samples was altered to be in the range of
0.1 to 0.4 on the Amott wettability scale. We also demonstrated that all the
coefficients required by the improved resistivity model are physically
meaningful. One of the unique contributions of this paper is the introduction
of a new interpretation diagram, called the wettability triangle. This diagram
can potentially be used to quantify wettability from resistivity measurements,
if combined with other geophysical measurements. The outcomes of this work are
promising for reliable interpretation of resistivity logs in mixed-wet
formations for improved assessment of hydrocarbon saturation with minimal
BIO: Chelsea Newgord
is petroleum engineering Master’s student in the Hildebrand Department of
Petroleum and Geosystems Engineering at The University of Texas at Austin.
Previously, she worked as a reservoir geophysicist at Sigma Cubed Integrated
Reservoir Services in Denver from 2012 to 2017. Her work included building
reservoir models from seismic and well-log data to identify drilling targets.
She graduated in 2012 with a BS degree in geophysical engineering from Colorado
School of Mines, with minors in geology and public affairs. She is a current
member of SPWLA, SPE, and SEG. Her research interests include core-analysis,
petrophysics, and integrated reservoir characterization.
New Orleans Chapter Open Positions: President Elect, Scholarship Committee Chair
Don't forget to renew your SPWLA Membership for 2019!