• A Study of How to Implement Alternative Well Plugging Materials in Governing Regulations 

      Skjeldestad, Fredrik (Master thesis, 2012)
      The governing requirements and regulations for petroleum activities on the Norwegian Continental Shelf (NCS) refers to the industry standard NORSOK D-010 for technical and functional requirements for Plug & Abandonment ...
    • An optimization model for the planning of offshore plug and abandonment campaigns 

      Bakker, Steffen J.; Vrålstad, Torbjørn; Tomasgard, Asgeir (Journal article; Peer reviewed, 2019)
      Plug and abandonment (P&A) operations can be time-consuming and thus very costly, especially for subsea fields. P&A of subsea wells require dedicated vessels such as high cost semi-submersible drilling rigs or lower cost ...
    • Cement Plug Integrity for Well Abandonment 

      Corina, Anisa Noor (Doctoral theses at NTNU;2020:30, Doctoral thesis, 2020)
      Permanent abandonment marks the end of the life of an oil or gas well. Accordingly, the penetrated formation must be isolated, preventing fluid flow to the surface or surrounding formation, with a purpose to give long-term ...
    • Flow properties of water-based drilling fluids 

      Kristensen, Aleksander (Master thesis, 2013)
      The objective of this master thesis was to investigate the flow properties of water based drilling fluids, utilizing measurements in both the micro and macro scale. The research was performed on two realistic drilling ...
    • Influence of Casing Shoe Depth on Sustained Casing Pressure 

      Eikås, Inger Kamilla (Master thesis, 2012)
      In 2006 the Petroleum Safety Authority Norway (PSA) performed a well integrity survey. The survey indicated that about 20 % of wells on the Norwegian Continental shelf (NCS) may suffer from well integrity issues. Most of ...
    • Numerical Modeling of Radial Fracturing of Cement Sheath Caused by Pressure Tests 

      Gheibi, Sohrab; Sangesland, Sigbjørn; Vrålstad, Torbjørn (Chapter, 2019)
      To achieve an acceptable level of zonal isolation, well integrity should be guaranteed in hydrocarbon production and geological CO2 sequestration. Well pressure test can cause different types of failures in the well system ...
    • Operational Procedure for permanent P&A of Subsea Wells 

      Breivik, Øyvind (Master thesis, 2015)
      All oil-and gas wells ever drilled on the Norwegian continental Shelf will be abandoned at some point. The operating companies are entitled ensure no leaking to the surface from the reservoir in an eternal perspective ...
    • Simulation of fluid flow through real microannuli geometries 

      Corina, Anisa Noor; Skorpa, Ragnhild; Sangesland, Sigbjørn; Vrålstad, Torbjørn (Journal article; Peer reviewed, 2020)
      Debonding of well cement towards casing or rock, i.e. microannuli formation, is a typical failure mode of cement barriers. Consequently, such microannuli may act as leak paths during leakages of downhole fluids such as ...
    • Vurdering av materialer for brønnsementering 

      Nguyen, Long Phi (Master thesis, 2012)
      En av de viktigste operasjonene i en brønnkonstruksjon er primærsementering. En dårlig utført primærsementering kan være en fare for både mennesker og miljøet rundt. En reduksjon i produktivitet, dyre sementering løsninger ...