The stratigraphic team at Network Stratigraphic Consulting
Ltd. has over 100 man years industrial experience, ranging geographically
around much of the world, including most of Europe, Africa, the Middle
East, South America and the Far East. Click
here for more information.
This group of stratigraphers has an excellent background
in both routine and high resolution stratigraphic studies having been
actively involved in everything from wellsite biostratigraphy in frontier
exploration areas through to detailed multidisciplinary multiwell studies
in mature petroleum provinces.
Currently staff are involved in a number of active field
development campaigns, carrying out wellsite biostratigraphy on a continuing
programme of horizontal wells with additional follow up analyses to
complete full stratigraphic reports. Other studies include:
- routine well analyses,
- high resolution intra-reservoir correlation projects,
- regional sequence stratigraphic reviews,
- evaluation of old biostratigraphic data/reports,
- quality auditing of existing biostratigraphic zonations
- detailed Tertiary studies as part of regional overburden evaluations.
It should also be noted that we have available to us a very experienced
team of contract wellsite biostratigraphers, specialising in the monitoring
of both exploration wells and horizontal production wells throughout
the Paleogene succession and into the Mesozoic sequence. The latter
is a particular specialist area for Network Stratigraphic Consulting
Ltd., primarily in carbonate field development in the Norwegian and
Danish offshore. All staff are fully qualified technically, as well
as carrying all the requisite health and safety certification for work
in the North Sea region (UK, Denmark & Norway).
In 1998 Network Stratigraphic Consulting Ltd. was invited to review
the Late Cretaceous Chalk stratigraphy of the triple point region of
the Central Graben. Results of this multiwell study were presented to
the JCR meeting in 1999 and published by the Norwegian Petroleum Directorate.
Network Stratigraphic Consulting Ltd. staff have carried
out field wide studies on Ekofisk, Eldfisk Alpha, Eldfisk Bravo, Valhall,
Hod, South Arne, Joanne, Hanze, in addition to other multiwell studies
in the Danish and German offshore.
These take many different forms and are not simple well to well correlations.
On Valhall we produced the first wellsite manual documenting the full
involvement of biostratigraphy and its use in field development. On
Ekofisk we have carried out detailed biostratigraphic studies on all
the available core across the field. On Eldfisk we have undertaken biofacies
studies in order to establish the variations in chalk sedimentation
and its effect on reservoir properties. Biofacies studies have also
been carried out on various stratigraphic units of the Miskar and Hasdrubal
Fields in Tunisia.
We have completed a 34 well review of the Narve (=Hod) Formation in the Valhall Formation integrating biostratigraphy with petrophysics for the first time to create a geological model.
Horizontal well monitoring
Over 200 wells drilled to date on the Valhall, Ekofisk, Eldfisk and
South Arne fields has used Network Stratigraphic Consulting Ltd. biostratigraphers
at the wellsite.
The most efficient and productive horizontal drilling programmes are
those which utilise all the hard work which has previously been put
into appraising the field. A huge amount of data will already exist;
this needs synthesising, supplementing and building into a viable stratigraphic
South Arne – Before the horizontal drilling programme
started Network Stratigraphic Consulting Ltd. re-evaluated all the data
from the exploration and appraisal wells drilled on the structure (I-1,
Baron-2, Rigs-1 & Rigs-2). A Stratigraphic Model was developed which
could be used and would evolve during the horizontal drilling programme.
Hanze – The Hanze field in offshore
Holland benefited from a multiwell biostratigraphic appraisal study
in order to identify the principal producing biofacies prior to horizontal
Ekofisk – During the early phase of horizontal well drilling on
Ekofisk, a biostratigraphic re-evaluation of every previous report and
all the available cored section from the reservoir was undertaken. The
value of good quality data cannot be underestimated.
Miskar – Much of the production
from the Miskar field comes from the Campanian – Maastrichtian
Abiod Chalk Formation. In addition to this additional production from
the calcispheric chalky limestones of the Turonian Bireno Formation
is being evaluated with the view of establishing a Stratigraphic Model
for use in biosteering horizontal wells through this secondary reservoir.
Network Stratigraphic Consulting Ltd. has carried out almost 200 wellsite
projects since the company was established in 1994. Of these projects,
approximately 80% included monitoring and biosteering horizontal wells.
Prior to the establishment of the company in June 1994,
our staff were involved in all the horizontal wellsite work on the Ekofisk,
Eldfisk, Valhall and Hod fields.
Staffing a horizontal well requires a two-man team working
twelve-hour shifts. They carry all their equipment with them, including
microscopes and laptop computers allowing sample processing, analysis
Valhall – First with Amoco Norway
and since January 1999 with BP Norge, Network Stratigraphic Consulting
Ltd. biostratigraphers have been directly and intimately involved in
development drilling on the Valhall and the adjacent Hod fields (over
70 wells). The reservoir sequences are zoned biostratigraphically, each
zone and subzone being defined by its own suite of nannofossils and
Ekofisk – Network Stratigraphic
Consulting Ltd. staff provided wellsite biosteering on the first horizontal
producer on the Ekofisk field drilled in 1992 by Phillips Petroleum.
Since June 1994 all horizontal wells on the field (total – 38)
have utilised wellsite biostratigraphers, working with an evolving stratigraphic
model for the field that is closely calibrated with the Reservoir Zones.
Eldfisk – Since June 1994, a total
of 42 horizontal wells have been drilled on the Alpha and Bravo structures
using Network Stratigraphic Consulting Ltd. wellsite staff. In addition
to this biostratigraphers have also assisted in casing picks.
South Arne – Network Stratigraphic
Consulting Ltd. has been involved in the development of the South Arne
field in Denmark since its very beginning. Staff helped to develop the
Stratigraphic Model and have been on all 19 horizontal wells drilled
since the spudding of SA-1 in the summer of 1998.
Satellite structures - wellsite biostratigraphers
have also been employed during the evaluation drilling of satellite
structures, including Nokken (2/8-15), Trud (2/8-17), Modi- 1, Ebba
and Embla, etc.
Other wellsite work includes horizontal wells on the Maureen
Field, Hod Field and Tor Field as well as numerous development wells
in the Greater Britannia area.
Infill analyses – following wellsite studies, infill micropalaeontology
and nannofossil analyses are carried out regularly in order to provide
a full cover of the whole well for both disciplines. This allows for
those times when staff are working shifts offshore. Full reports are
produced on all wells studied offshore.
Multiwell correlation studies –
it is a simple exercise, with the Stratabugs software used in-house,
to collate multiwell correlation panels showing important biostratigraphic
marker events, wireline logs, etc.
Field review studies – horizontal wells generate
a vast amount of very useful data that can be used in evaluating associated
aspects of the field. Working and collaborating with other specialists
(geophysicists, sedimentologists, etc.) We can help to ascertain facies
studies, sedimentological variations, structural history, faulting,