Multi-scale Reservoir Characterization using LWD Technologies for Informed Operational Decisions, Yme Field, Norway (Sven S. Gundersen, Repsol Norge)


Sven S. Gundersen from Repsol Norge


Mathias Horstmann SLB, Per Erik Wærum, Repsol Norge


Advances in the logging while drilling (LWD) technology have drastically impacted the E&P activities of the Energy Industry. LWD tools now provide a very robust set of information in real-time (RT) with quality and resolution, earlier available only through wireline logging and continuous core.

Real-time geological interpretation while drilling can be achieved with high-resolution borehole images; however, the use of different drilling fluids, telemetry-related limitations, and non-optimal depth control on rigs often leave geoscientists with limited and impaired data, leading to inconsistencies over a field’s life cycle. This study from offshore Norway presents applications of new measurements and algorithms to address such challenges providing consistent borehole imaging for geological interpretations while drilling various and complex subsurface.

Latest generation images are game changers for drilling operations, reservoir mapping and characterization. High-quality acquisition not only enables more accurate data-based decisions in RT, improving drilling or optimizing completion and operational efficiency, but also helps performing comprehensive formation and reservoir evaluation with recorded data available in the tool’s memory.

New multi-physics high-resolution LWD (logging while drilling) technology was deployed for real-time imaging in boreholes drilled with nonconductive fluids, addressing technology gaps that earlier allowed such services only in conductive aqueous fluids and providing much-needed independence to drill various well trajectories in any mud configuration without limiting high-resolution imaging for geological, petrophysical, and geomechanical interpretation. Correspondingly, real-time data transmission challenges were addressed with improved mud-pulse telemetry or wired drill-pipe. Furthermore, new application algorithms were developed to compensate for inadequate depth control impacting the integrity of high-resolution data.

We present results from a field development with recently drilled wells through reservoirs in Middle Jurassic sandstones of the Sandnes Formation, in a field in the southeastern part of the Norwegian sector of the North Sea. They represent prominent examples where complete set of LWD technologies were successfully used to fulfill a series of objectives. We describe how RT and recorded LWD borehole image (BHI) interpretation in combination with advanced petrophysical logs and ultra deep reservoir mapping provided valuable multi-scale insights on fault and fracture distribution, structural dip and sedimentary information. This study enabled informed operational decisions in active geosteering, reservoir management and compartmentalization assessment, detailed reservoir characterization, wellbore stability evaluation, and RT well completion definition.

Recently drilled wells present an excellent example of how state-of-the-art LWD technologies add value to the reservoir understanding, and geological and petrophysical characterization. The integration of diverse LWD tools and technologies, with different physics and scales, configures a powerful methodology to characterize the well both in RT and during post drilling evaluation, supporting operation decisions, enabling high-resolution reservoir characterization.

An integrated analysis using RT and memory LWD data allowed the characterization the Yme reservoir, and the definition of the best strategy to complete the well. High resolution RT data and BHI permitted the identification of faults, fracture damage zones, diagenetic and sedimentary features. Together with other advanced petrophysical logs, formation pressure measurements and UDAR inversions, this data set provided critical information on time to take valuable operational drilling and completions decisions, increasing efficiency and decreasing operational costs.

Presentation is built and referred to

  1. Vieira De Luca, P.H., Gundersen, S,S,, Wærum, P.E., Horstmann, M. and Shrivastava, C., 2023, “Multi-scale Reservoir Characterization using LWD Technologies for Informed Operational Decisions, Yme field, Norway.” Conference Paper, 84th EAGE Annual Conference, Volume 2023, p.1 – 5

  2. Horstman, M., Shrivastava, C., Adrian A., Goswami, R., Sikdar, K, Bakke, B. A., Aasheim, O, Kollien, T, and Stirø, Ø. 2022, “Comprehending Complex Clastics: Consistent Real-Time Geological Borehole Imaging Independent of Drilling Fluid and Telemetry Limitations.” SPWLA-2022-0096, 63rd Annual Logging Symposium, Stavanger, Norway, June 2022


Sven S. Gundersen; Senior Petrophysicist Graduated from Høgskolen i Stavanger in 1998 as Petroleum Engineer 25 years in the oil industry working mostly with Formation Evaluation/Petrophysics and data processing.

Background : Years 1998-2010: Worked for Baker Hughes (INTEQ) in the Geoscience dept. with Log QC, interpretation, processing and as a LWD Service coordinator. 2010-2015 : Started in Talisman as an Operation Geologist for one year before moving back into Petrophysics. 2015-2023: Petrophysicist with Repsol Norge AS, and is currently Sr. Pet.phys working with the Yme field.