© 2015 TGS-NOPEC Geophysical Company ASA. All rights reserved.

See the energy at TGS.com

Post Well Analysis (PWA) BARENTS SEA

Exploration successes occur when all the following prerequisites are fulfilled:

� Presence of effective RESERVOIR

� Presence of effective SEAL (top, fault and lateral seals)

� Presence of TRAP prior to hydrocarbon charge (structural and/or stratigraphic)

� Hydrocarbon CHARGE (generation/migration)

By analyzing the reasons for success and failure we can learn more about the hydrocarbon system in which the well was drilled, and improve the chances of success in the future. TGS has reviewed the most representative exploration wells (84) drilled to test independent prospects in the Norwegian part of the Barents Sea. All prospective levels in each well were investigated irrespective of the primary target of the well.

Well Data

The following data sources provide input to the analysis:

� Norwegian Petroleum Directorate (NPD) website

� Original composite logs, well reports, etc.

� TGS’ Barents Sea Facies Map Browser (including litho-/chronostratigraphy)

� TGS’ petrophysical database (CPI)

� Geochemical and well pressure data

Seismic Data

For the evaluation of geometric properties of traps and for maturation modelling of drainage areas, a regular regional grid of 2D data has been utilized. This seismic grid consists mainly of the NBR long offset data (approx. 80,000 km). Furthermore, public data (2D and 3D) was used where appropriate.

© 2015 TGS-NOPEC Geophysical Company ASA. All rights reserved.

See the energy at TGS.com

Deliverables

The Barents Sea Post Well Analysis (BS PWA) is a new GIS-based exploration aid. It is designed to analyze and explore the full range of factors influencing the presence/quality of trap, reservoir, seal and hydrocarbon charge (including retention) for all prospective levels in all tested structures.

The project addresses 84 released exploration wells by extracting parameter subsets from all prospective intervals.

Data recorded includes:

1. General well information

2. Reservoirs

� Lithological, stratigraphic and facies features

� Petrophysical parameters (N/G, av. poroperms)

3. Traps

� Type, closure, faults and effectiveness

� Timing of emplacement, modification, exhumation, DHI

4. Seals

� Top seal; lithological, stratigraphic and facies features

� Bottom seal, critical seal, waste and thief zones

5. Hydrocarbons

� Type and features of HC columns and/or shows

� Retention

6. Charges

� Lithological, stratigraphic and facies features

� Quality of source in well including average TOC and HI, max maturity, max and present day temperature, age of expulsion

� Quality of source in the kitchen

� Migration

The PWA also includes general information on the SINTEF boreholes and unreleased well data in the Barents Sea for a comprehensive well database.

Data Viewer

The database is delivered as an ESRI ArcGIS Geodatabase, in Access® or binary format, containing all spatial data and spatial analysis using data types supported by ArcGIS software.

TGS is also seeking to develop a Facies Map Browser (FMB) PWA plug-in, so the PWA can be viewed and queried within the FMB regional geological interpretation tool without the need for a separate ArcGIS license.

Query Tool

The PWA will include a query toolbar to enable graphical representation of regional and localized query results. There are multiple queries and these will include:

� Reservoir presence, effectiveness and fluids

� Trap type, effectiveness and retention failure

� Top seal and critical seal

� Charge rating (up to 5 charges per reservoir)

� Main failure mechanism

Images

The database also includes images of the following:

� A pie chart scheme that summarizes the results of each well (PDF)

� Lithostratigraphy and wireline data for each well (JPG)

� One image minimum of a representative seismic line for each well (PDF)

� One grid map minimum for a representative horizon for each well (PDF)

Benefits

� Complete well parameter interpretation in a single location saves time

� Access to collated learning from well failures and successes facilitates new analytical approaches (within the GIS-environment) and reduces future risk of drilling dry holes

� Graphical display of queries for reservoir, seal, trap and charge improves understanding of petroleum systems

For more information, contact TGS at:

UK Tel: +44 208 339 4200Email: gps-sales@tgs.com

Access is a registered trademark of Microsoft Corporation in the United States and/or other countries