PETROLEUM-PETROLEUM

Prosjektet "Forbedret prediksjon av stress- og poretrykksforandringer i takbergarten for tilleggsboring" tar for seg sentrale utfordringer innen olje- og gassoperasjoner, med mål om å forbedre sikkerhet, effektivitet og bærekraft. Tilleggsboring, som innebærer boring av ekstra brønner i allerede produserende reservoarer for å maksimere utvinning, møter ofte risiko knyttet til produksjonsrelaterte endringer i undergrunnen. Dette inkluderer deformasjoner og trykkendringer i formasjonene over reservoaret (takbergarten), som kan føre til ustabile boreforhold, forsinkelser, lekkasjer eller i verste fall gjøre boring umulig. For å redusere risikoen, er avanserte verktøy for bedre planlegging og styring av operasjonene avgjørende. En viktig metode i industrien, seismisk tidsforskyvningsanalyse, innebærer å sammenligne gjentatte seismiske undersøkelser over tid for å oppdage endringer i seismiske bølgers hastighet forårsaket av deformasjoner i undergrunnen. Prosjektet utviklet en kalibrert bergfysisk modell, og tilhørende programvare, for å forutsi slike tidsforskyvninger, som tar hensyn til materialegenskaper og anisotropi som skyldes den fine lagdelingen i takbergarten. Feltdata levert av industripartnere ble brukt til å validere modellen, som koblet seismiske tidsforskyvninger til detaljerte 3D-representasjoner av deformasjonene. Analysen avdekket betydelige variasjoner i deformasjon og tidsforskyvning mellom ulike lokasjoner og retninger, påvirket av stivhetskontraster mellom reservoar og takbergart samt reservoargeometri. Disse funnene har praktiske implikasjoner for tilleggsboring som muliggjør omfattende kartlegging av deformasjoner og trykkendringer i undergrunnen ved bruk av seismiske tidsforskyvninger. Dette støtter tryggere operasjoner ved å redusere risiko som brønnkollaps og oppsprekking, forbedre brønnplasseringen og minimere miljøpåvirkningen. I tillegg bidrar det til en bærekraftig praksis ved å optimalisere ressursutvinning og redusere uforutsette driftsavbrudd. Den utviklede programvaren integrerer geomekaniske simuleringer med 4D-seismiske data, og gjør det mulig for industripartnere å forbedre sine geomekaniske modeller. Utover anvendelser innen petroleumsproduksjon og CO2-lagring, har dette verktøyet potensiale for å fremme energilagring og geotermiske prosjekter. Ved å kombinere seismikk, geomekanikk og bergfysisk modellering sikres en tryggere og mer bærekraftig praksis i olje- og gassindustrien, samtidig som det bidrar til det grønne skiftet gjennom innovative tilnærminger til utnyttelse av undergrunnsressurser. Industripartnere vil dele resultater fra storskala feltapplikasjoner i et seminar, noe som fremmer bredere anvendelse og fortsatt innovasjon.

The project advances methodologies for integrating seismic time-shift data into geomechanical modelling workflows to improve predictions of subsurface deformations. A primary outcome is a software tool that enables more accurate quantification of deformations in oil and gas fields. This tool is now being utilized by the industry, enhancing planning and operational safety when drilling additional wells into producing reservoirs (infill drilling), particularly in the complex formations above the reservoir. This reduces risks, such as casing collapse and caprock failure. We have clearly demonstrated the need for interdisciplinary research collaboration in this field, fostering knowledge exchange across geomechanics, rock physics, and repeated (4D) seismic data analysis. This approach bridges research and industry application by interpreting 4D seismic data in terms of deformations (geomechanics) using a rock physics model. The calibrated rock physics model, based laboratory data provided by SINTEF, underscores the critical role of national research infrastructure in conducting advanced rock testing. The industry collaboration has included representatives from assets outside Norway, demonstrating the international applicability of the results. Heriot-Watt University in Edinburgh and NTNU contributed significantly to achieving the project objectives, thereby strengthening collaboration between academia, the institute sector, and industry. Improved prediction tools support better well placement, reduced environmental risks, and optimized resource recovery. By minimizing unplanned downtime and the need for additional wells, the industry benefits from improved efficiency and a reduced environmental footprint as fewer wells are required. Thus, the project contributes to sustainable and safe drilling practices, essential for the Norwegian continental shelf. Beyond oil and gas applications, the tools and methodologies developed are directly relevant to emerging fields such as CO2 storage and hydrogen storage, which require cost-efficient solutions. Accurate geomechanical modelling of subsurface changes is critical for safely repurposing depleted reservoirs for green energy initiatives, a transition of substantial promise for Norway's energy future. In summary, the project enhances the value of close collaboration between academia and industry, delivering tools that advance scientific understanding and address key industry challenges related to drilling in mature environments. The cross-disciplinary approach lays a foundation for safer, more efficient, and environmentally responsible subsurface operations in complex environments such as offshore Norway. These innovations align with society’s expectations for sustainable and responsible resource management.

Infill drilling means to drill more wells into oil and gas producing reservoirs for increased recovery. However, drilling into already producing reservoirs is often a major challenge. The production of a petroleum reservoir implies strains in the subsurface, not only of the reservoir itself, but also deformations, stress and pore pressure changes in the overlaying rocks (overburden). These overburden alterations often result in challenging infill drilling conditions posing severe risk for the wells, equipment and environment. In some cases, infill drilling may not even be possible due to severe alterations in the subsurface. However, these issues may be avoided with better planning and tools. Accurate predictions of stress and pore-pressure changes are therefore essential for safe and efficient drilling. The monitoring of the overburden changes is often done with repeated seismic. By comparing seismic data from different stages of the production one may translate this into information needed for successful infill drilling. However, a prerequisite for this interpretation is that adequate tools are available. In this project we will provide a toolbox (Rock Physics Toolbox) containing experimental data, models, and guidelines from which the industry can pick suitable tools for optimizing their infill drilling. This will result in improved efficiency, lower costs and improved safety for drilling operations in producing fields. This research will also strengthen the position of SINTEF's Formation Physics Laboratory, being one of the very few laboratories in the world providing advanced and integrated testing and modelling of shales and other tight rocks for the petroleum sector. The tools of this project are also relevant for improved monitoring of CO2 storage.