GeoSpec12
NMR core analysis with enhanced sensitivity

GeoSpec12
NMR core measurements on shales pose particular problems due
to low porosity and small pores. Oxford Instruments’ GeoSpec12
addresses the problem.
Oxford Instruments has been supplying benchtop
NMR instruments for core analysis since the early
1990s, when they were introduced to support thedevelopment and use of downhole NMR logging
tools.
Most models in the GeoSpec range operate at
an NMR frequency of 2MHz, to emulate downhole
tools and also to minimise measurement artefactscaused by the paramagnetic material often found insandstones. However, in recent years there has beena shift towards oil and gas exploration in shales,
which has brought about a reappraisal of the useof NMR for core analysis because of the structuraldifferences in the rock types. Whereas sandstones
have typically 15-25% porosity and pore sizes of tens
to hundreds of microns, shales are more likely tohave 2-15% porosity and pores only a hundredth thesize of sandstone pores. From the NMR perspective
this means there is much less fluid from which toobtain an NMR signal, and a need to reach shorterecho times in order to observe the shorter T2 signals
from the smaller pores.
Oxford Instruments first addressed this problem
with the introduction of Q-Sense technology tothe GeoSpec range, to allow shorter echo times
and improved signal to noise ratios. Now, we haveintroduced a new model, GeoSpec12, to further
improve sensitivity for low porosity materials byoffering a higher operating frequency.
Base specifications

Image of 3 cores

Operating field (frequency)

0.28T (12MHz proton
resonance)

Maximum sample diameter

53mm

Gradient strength>20 gauss/cm on three axes

Minimum tau(43mm probe)

35µs

GeoSpec12 operates at 12MHz, which gives
improved sensitivity over 2MHz measurements while
not being high enough to give significant magnetic
susceptibility artefacts, particularly with shale
samples. Measurements made at 12MHz show anincrease in sensitivity of about 10 times, compared tomeasurements at 2MHz. This means that comparable
signal to noise ratio (SNR) measurements can bemade in about one hundredth of the measurement
time required at 2MHz.
Green Imaging Technologies LithoMetrix software
is supplied as standard for routine measurements
including porosity, 1D relaxation distributions (T1 orT2) and free/bound water determinations. For moreadvanced users, GeoSpec12 can be equippedwith one- or three-axis pulsed field gradients topermit diffusion based measurements, profiling,and imaging. Corresponding software upgrades
are available to GIT Systems Advanced formeasurement of capillary pressure, gas isotherms,

spatially-located T2 distributions, 2D mapping (T1-T2 andT2-diffusion), and 1D profiles, and to GIT Systems
Advanced 3D for full 3D imaging. The superb
A full suite of 3D
viewing and analysis
tools is included with
GIT Systems 3D
imaging software

sensitivity of the GeoSpec12 gives the temporal
resolution required for flooding experiments, andcombined with extensive rock based imaging sequencessuch as SPRITE and short Tau FSE, creates a revolution
in core analysis.
Vuggy carbonate
plug imaged in
Geospec12

GeoSpec12 can also be fitted with the P5
Overburden Cell for 1” or 1.5” core plugs, toallow measurements at up to 5000psi (1” cores) or
2500psi (1.5” cores), and up to 100°C. Please note that
additional equipment is needed to generate and control
pressures and temperature.

Global Support
The Oxford Instruments – Green Imaging Technologies partnership has experienceof supplying systems all over the world, with instruments installed on 6 continents.
Our hardware and software is developed, built and tested in-house.
We have our own core analysis laboratory, providing a service specialising in difficult
rocks, which can be used to validate your own results or act as a backup to your own
production lab. We have support bases in the UK, the USA, Canada, and China, as well as
a network of partners and resellers with global reach. No matter where you are located, ourglobal support network can provide prompt, personal service.

Oxford Instruments Magnetic ResonanceGreen Imaging Technologies

For almost 30 years, Oxford Instruments has been theindustry standard for NMR instrumentation for core analysis.
With over a hundred installations, Oxford Instruments truly
understands the needs of core analysts, whether they be inoil companies, oilfield service companies or academia.

Green Imaging Technologies (GIT) is the world-leaderin developing innovative solutions for lab-based rockanalysis using NMR. GIT’s products and services offer
fast, accurate, non-destructive analysis of rock coresamples used by the oil and gas industry in exploration
and reservoir characterisation.

Innovation has been the driving force behind Oxford
Instruments’ growth and success ever since the businessspun out from the University of Oxford over 50 years ago.
It is now a global company with over 1,300 staff worldwide
and a listing on the London Stock Exchange (OXIG).
Oxford Instruments Magnetic Resonance
For more information: magres@oxinst.com
www.oxinst.com/geospec

Over the last decade, GIT’s product offerings haveevolved and expanded to include a full suite of routine
and advanced core analysis tools. A culture of continual
innovation has driven the company to become theindustry leader in NMR core analysis. From prediction toproduction, GIT provides the solution.
For more information: info@greenimaging.com

UKUSA

www.greenimaging.com

Tubney Woods, Abingdon
Oxfordshire, OX13 5QX, UK300 Baker Avenue, Suite 150
Concord, MA, 01742, USACanada

Tel: +44 (0) 1865 393 200
Fax: +44 (0) 1865 393 333

Tel: +1 978 369 9933
Fax: +1 978 369 8287

China
Floor 1, Building 60, No.461, Hongcao Road,Shanghai, 200233, China

520 Brookside Drive, Suite B
Fredericton, NB, Canada, E3A 8V2Toll Free: +1 888 944 8462
Tel: +1 506 458 9992
Fax: +1 506 458 9615

Tel: +86 21 6073 2925 Fax: +86 21 6360 8535

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acknowledges all trademarks and registrations. © Oxford Instruments plc, 2018. All rights reserved. Ref: GeoSpec12-07-18