• Annular frictional pressure losses for drilling fluids 

      Saasen, Arild; Ytrehus, Jan David; Lund, Bjørnar (Peer reviewed; Journal article, 2020)
      In the paper it is demonstrated how a Herschel-Bulkley fluid model, where the parameters are selected from relevant shear rate range of the flow and are parametrically independent, can be used for pressure loss calculations. ...
    • Annular frictional pressure losses for drilling fluids 

      Saasen, Arild; Ytrehus, Jan David; Lund, Bjørnar (Peer reviewed; Journal article, 2021)
      In the paper, it is demonstrated how a Herschel–Bulkley fluid model, where the parameters are selected from relevant shear rate range of the flow and are parametrically independent, can be used for pressure loss calculations. ...
    • Assessment of Yield Stress in Oil-Based Drilling Fluids 

      Ytrehus, Jan David; Feneuil, Blandine Fleur Prudence; Saasen, Arild (Peer reviewed; Journal article, 2023)
      Yield stress is commonly used to describe the rheological properties of drilling fluids. There are various methods to define such yield stress. Some approaches provide yield stress values sufficient to derive a proper fluid ...
    • Cement Placement: An Overview of Fluid Displacement Techniques and Modelling 

      Foroushan, Hanieh K.; Lunde, Bjørnar; Ytrehus, Jan David; Saasen, Arild (Peer reviewed; Journal article, 2021-01)
      During drilling operations, effective displacement of fluids can provide high-quality cementing jobs, ensuring zonal isolation and strong bonding of cement with casing and formation. Poor cement placements due to incomplete ...
    • Cuttings transport with oil- and water-based drilling fluids 

      Ytrehus, Jan David; Lund, Bjørnar; Taghipour, Ali; Saasen, Arild (Chapter, 2021)
      Deviated well sections are common in modern well construction. In mature areas like the North Sea region, practically all producers or injector wells will have highly deviated sections. These wells must be drilled and ...
    • The Effect of Different Drilling Fluids on Mechanical Friction 

      Ytrehus, Jan David; Taghipour, Ali; Golchin, Arash; Saasen, Arild; Prakash, Braham (Peer reviewed; Journal article, 2017)
      A very important aspect in highly inclined wellbores is the mechanical friction. For extended reach drilling (ERD) and through tubing extended reach drilling (TTERD) this can be a limiting factor. Friction caused by the ...
    • Experimental Bench-Scale Study on Cuttings-Bed Erosion in Horizontal Wells 

      Pedrosa Consicion, Herman Camilo; Lund, Bjørnar; Opedal, Nils van der Tuuk; Ytrehus, Jan David; Saasen, Arild (Peer reviewed; Journal article, 2022)
      Cuttings-beds formation while drilling wellbores is a common challenge, especially for horizontal wells, as drilled particles have higher area to be deposited and form cuttings-beds, which can cause several problems such ...
    • Experimental Methods for Investigation of Drilling Fluid Displacement in Irregular Annuli 

      Lund, Bjørnar; Taghipour, Ali; Ytrehus, Jan David; Saasen, Arild (Peer reviewed; Journal article, 2020)
      Experimental methods are still indispensable for fluid mechanics research, despite advancements in the modelling and computer simulation field. Experimental data are vital for validating simulations of complex flow systems. ...
    • Fundamentals and physical principles for drilled cuttings transport – Cuttings bed sedimentation and erosion 

      Pedrosa, Camilo; Saasen, Arild; Ytrehus, Jan David (Peer reviewed; Journal article, 2021)
      The increasing necessity of challenging wellbore structures and drilling optimization for improved hole cuttings cleaning has been growing along time. As a result, operator companies have been researching and applying ...
    • Hole cleaning and wet-granular rheology of rock cutting beds: Impact of drilling fluid composition 

      Pedrosa, Camilo; Saasen, Arild; Ytrehus, Jan David (Peer reviewed; Journal article, 2022)
      Cuttings-beds formation is an issue that must be considered during all wellbore drilling operations. This problem increases at highly deviated or horizontal wells, where cuttings removal efficiency becomes one of the most ...
    • Hydraulic Behavior in Cased and Open Hole Sections in Highly Deviated Wellbores 

      Ytrehus, Jan David; Lund, Bjørnar; Taghipour, Ali; Kosberg, Birgitte Ruud; Carazza, Luca; Gyland, Knud Richard; Saasen, Arild (Chapter, 2019)
      In this paper we present results from flow loop experiments with an oil-based drilling fluid with micronized barite as weight materials. The use of micronized barite allows using lower viscosity drilling fluid, providing ...
    • Oil-based drilling fluid's cuttings bed removal properties for deviated wellbores 

      Ytrehus, Jan David; Lund, Bjørnar; Taghipour, Ali; Carazza, Luca; Gyland, Knud Richard; Saasen, Arild (Peer reviewed; Journal article, 2021)
      Results from cuttings transport tests in the laboratory using different field-applied oil-based drilling fluids with similar weight and varying viscosities are presented in this paper. The fluids are designed for highly ...
    • Plug & abandonment of offshore wells: Ensuring long-term well integrity and cost-efficiency 

      Vrålstad, Torbjørn; Saasen, Arild; Fjær, Erling; Øia, Thomas; Ytrehus, Jan David; Khalifeh, Mahmoud (Peer reviewed; Journal article, 2019-10)
      There is an upcoming "P&A wave" of wells that need to be permanently plugged and abandoned, especially in mature, offshore areas such as the North Sea and Gulf of Mexico. It is important to ensure that plugged wells do not ...
    • Viscosity Models for Drilling Fluids: Herschel-Bulkley Parameters and Their Use 

      Saasen, Arild; Ytrehus, Jan David (Peer reviewed; Journal article, 2020-10)
      An evaluation is presented of the practical usage of the Herschel-Bulkley viscosity model for drilling fluids. If data from automatic viscosity measurements exist, the parameters should be selected from relevant shear rate ...
    • Wet Drilled Cuttings Bed Rheology 

      Pedrosa, Camilo; Saasen, Arild; Lund, Bjørnar; Ytrehus, Jan David (Peer reviewed; Journal article, 2021)
      The cuttings transport efficiency of various drilling fluids has been studied in several approaches. This is an important aspect, since hole cleaning is often a bottleneck in well construction. The studies so far have ...
    • Wet-granular rheology to measure cuttings-bed strength 

      Pedrosa, Camilo; Ytrehus, Jan David; Aschl, Timothy; Lund, Bjørnar; Saasen, Arild (Peer reviewed; Journal article, 2021)
      Drilled cuttings-bed formation is a natural process during wellbore drilling operations, although it is not desired. To optimally remove the drilled cuttings out of the wellbore it is important to break the formed beds. ...