Applied Micropaleontology:
unravelling the petroleum systems with foraminifera
Biostratigraphy and applied
micropaleontology are essential
tools in exploration activities for
oil and gas industry. Microfossils,
such as foraminifera, are of high
importance since they occur in a
variety of marine environments and
through the geological time. TNO’s
Geobiology team offers applied
research in micropaleontology
combining up-to-date academic
research and practical expertise to
assist the E&P industry.
Foraminifera
BenO uGE 073 05­­-2009
Foraminifera are protozoans with a skeleton that is readily preserved in the fossil record.
Both planktic (i.e., living in the water column) and benthic (i.e., living on the sea floor) species
occur and have for decades been subject of extensive research. Their paramount importance
for (paleo-) environmental studies is well-known in academy as well as in industry.
Applied research in micropaleontology combining
up-to-date academic research
Paleodepth model
based on marker
foraminifera and
variation in the
microfossils
assemblages: an
example from the
Paleocene in the
Southern Tethys.
Together with their high preservation
potential, the wide range of environments
in which foraminifera occur makes
them ideal tools for biostratigraphy and
paleoenvironmental studies. In general,
the benthic group is more suitable for
reconstructing depositional environments,
as the occurrence of certain species is
restricted to well-defined habitats. The
planktic group is highly suitable for detailed
biostratigraphical age-dating and correlation
due to its cosmopolitan distribution and high
evolutionary rates.
The small dimensions and the relatively easy
and safe preparation methodology make
foraminifera highly suitable for projects
using cuttings and cores from boreholes.
The procedure takes relatively little time.
Applications include the interpretation of
hot-shots and biosteering during drilling
operations.
Paleoenvironmental changes during the
Paleocene (Danian-Selandian) in Tunisia
based on variations in the foraminifera and
organic-dinocysts assemblages. The integration
of different microfossils suggest that the
environment evolved from an outer neritic
oligotrophic in the Danian toward a shallower
nutrient-rich setting in the Selandian.
Paleoenvironmental approach
Oil and gas
In oil and gas exploration biostratigraphy
and paleoenvironmental reconstructions
are the most common applications of
microfossils. Whereas biostratigraphy
provides the temporal constraint of
rock units based on the fossil content,
paleoenvironmental reconstruction provides
the interpretation of the depositional
environment in which the rock was formed.
The main advantage of the microfossils is
represented by the small dimension of such
organisms which allow interpretation using
cuttings and cores from boreholes. Another
advantage is the relatively easy and safe
preparation, ideal also for results in brief
time, such as hot shot and during on-time
drilling operation.
TNO provides studies for hydrocarbon
exploration and production companies,
ranging from age determination of single
and multiple wells, paleoenvironmental
studies and biosteering. Projects can
benefit from the close relation with Utrecht
University. TNO’s target is to develop
new techniques on the requirement of the
companies combining expertise in the field
and up-to-date academic insight.
Since the increase need for detailed
stratigraphy, the classical biostratigraphy
does not provide sufficient information.
Therefore, paleoenvironmental
interpretation is more and more required.
Quantitative and semi-quantitative
micropaleontological analyses provide
information on the paleoenvironmental
changes, such as paleobathymetric variation
and also paleoproductivity. Paloebathymetry
is mainly determinate by the integration
of depth marker species, and the ratio
between the number of planktic and the
benthic foraminifera. In order to have a
more reliable picture, the combination with
other microfossils (e.g. ostracods, pyritized
diatoms and radiolaria) is also used.
Applied Micropaleontology
Biosteering in horizontal well using microfossils in order to confine the drilling in the reservoir
target.
Geo Energy and Geo Information
TNO Built Environment and Geosciences
Geological Survey of the Netherlands is the
central geoscience centre in the Netherlands
for information and research to promote the
sustainable management and use of the subsurface and its natural resources.
Wellsite Biostratigraphy
TNO Built Environment and Geosciences
Geological Survey of the Netherlands
The purpose of wellsite micropaleontology is to control the
stratigraphy during drilling operation and to assist steering
(biosteering) in horizontal well. Additionally, setting the casing point
using a micropaleontological approach is proved to be successful in
several wells.
Relevant wellsite experience ranges from the Cretaceous to the
Paleogene in the North Sea.
Princetonlaan 6
PO Box 80015
3508 TA Utrecht
The Netherlands
T +31 30 256 46 00
F +31 30 256 46 05
E [email protected]
tno.nl