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Our scientific staff cover a wide range of expertise gained from many parts of the globe, dealing with many and varied
projects. The unique combination of in-house geological services and a staff boasting extensive offshore and oil company
experience provides a competitive edge ito our services. We offer complete services within the disciplines of Petroleum
Geochemistry, Biostratigraphy and Petroleum Systems Analysis, and our customers expect high standards of quality in both
analysis and reporting.
High quality analyses and consulting services to the oil industry
Geochemistry services
In addition to providing a full range of geochemical
analyses of unsurpassed quality analysis, APT also
offers insightful and tailor-made interpretation,
integrated data reporting, and basin modelling and
consulting services. We pride ourselves on quality
and flexibility, and perform analyses and report
results to our clients’ specifications.
Biostratigraphic analysis and services
APT delivers a full range of biostratigraphic services,
ranging from single well reports and reviews of existing
data to full-scale field or basin-wide evaluations. We take
no established truths for granted, and we turn every stone
in the attempt to bring the stratigraphic knowledge a few
steps forward.
Petroleum systems analysis
APT has gained extensive experience in Petroleum
Systems Analysis using the ”PetroMod” suite of programs.
Projects range from simple 1d modeling of a set of wells to
complicated 3D models with maturation, kinetics, generation,
expulsion, and migration and accumulation issues to be
resolved or predicted.
Geochemistry services
• Analytical services
• Reporting
• Interpretation
• Exploration Solutions
• Petroleum consulting services
Biostratigraphy
• 24 hours Hot Shot analysis
• Routine biostratigraphy
• Well-site biostratigraphy
Petroleum System Analysis
• Analysis
• Interpretation
• Data Reporting
• PetroMod or other tools
APT- Applied Petroleum Technology Group
www.aptec.no
APT Group- Head Office Norway
nm@aptec.no
APT (UK) Ltd
patrick.barnard@aptuk.co.uk
APT (Canada) Ltd
mf@aptec.ca
collected from gas samples from the platform seemed to
indicate that the source was microbiological. Preliminary
data then seemed contradictory, and it was not clear what
the source actually was. A more thorough investigation was
authorised that involved the collection and analysis of gas,
water, and oil samples from multiple locations. This more
comprehensive data set revealed that H 2 S of non-biological
origin was present in some production fluids obtained
directly from wellhead and primary separator samples, but
H 2 S of biological origin was also present in many samples
obtained from the topside water handling system.
This case study demonstrated that only by obtaining
comprehensive data from multiple samples that included H 2 S
quantification, sulphur isotopic ratios in gas and water samples,
microbiological data from growth and genetic testing, and
water chemistry testing to quantify organic acids was it possible
to conclude that there were two sources of H 2 S in samples
from this offshore platform. The oil company now knows that
thermogenic H 2 S is migrating into the oil production reservoir
and that the topside water-handling system is vulnerable to
microbial contamination, and it can plan accordingly.
Chemical or Biological?
The confusion regarding the source of the H 2 S resulted
from sample collection by field production personnel who
were not experienced in reservoir souring, geochemistry, or
microbiology. After routine monitoring of gas stream samples
revealed detectable concentrations of H 2 S at a location on the
oil platform, the result was confirmed with additional field
measurements. Management subsequently requested that the
oil production personnel should collect H 2 S samples using an
Isotrap and they should perform additional field measurements
of H 2 S at various locations on the platform. The source of H 2 S
(from chemical or from biological processes) can often be
determined by quantifying the amounts of the stable isotopes
of sulphur, chiefly 32 S and 34 S. Chemical processes generally do
not discriminate between isotopes, whereas biochemical and
microbiological processes have a preference for 32 S. Therefore,
if a reaction product is depleted in 34 S as compared with the
starting material, then the reaction can be determined to be
biochemical.
The analyses to quantify the various stable isotopes of
sulphur require a sufficient mass of H 2 S, and the Isotrap device
is designed to collect the necessary amount. When the Isotrap
was placed on the gas outlet of the separator serving the well
where H 2 S had been observed, it failed to completely fill the
device over a period of a few hours. However, during that time it
was determined that higher H 2 S concentrations were detected at
a nearby location in the water treatment system, which received
water from this separator. When the Isotrap was moved to this
location it filled quickly and was then sent to the laboratory. The
amount of 34 S present in this sample was 8.3‰, a value that is
relatively low and was interpreted to be possibly consistent with
microbiologically produced H 2 S, fostering concern within the
GEOExPro November 2015 61