• A new approach to dynamic barite sag analysis on typical Field oil-based drilling fluid 

      Ofei, Titus Ntow; Lund, Bjørnar; Saasen, Arild; Sangesland, Sigbjørn; Gyland, Knud Richard; Linga, Harald (Chapter, 2019)
      Laboratory and field experiences record that sagging of weighting agents such as barite in drilling fluids is often worse in dynamic conditions, e.g. pumping, tripping or drill pipe rotation, than in static conditions. ...
    • Effect of Barite on the Rheological Properties of an Oil-Based Drilling Fluid 

      Ofei, Titus Ntow; Lund, Bjørnar; Gyland, Knud Richard; Saasen, Arild (Peer reviewed; Journal article, 2020)
    • Effect of Preconditioning and Ageing on Rheological Properties of Model Drilling Fluids 

      Werner, Benjamin; Lund, Bjørnar; Kosberg, Birgitte; Johansen, Espen; Giil, Gunnar Lia; Ytrehus, Jan David (Chapter, 2017)
      Many drilling fluids are thixotropic, meaning that viscosity decreases with time when subjected to shear. Other fluids may show anti-thixotropic (rheopectic) behavior, i.e. viscosity increase with time when subjected to ...
    • Hole-cleaning performance comparison of oil-based and water-based drilling fluids 

      Sayindla, Sneha; Lund, Bjørnar; Ytrehus, Jan David; Saasen, Arild (Journal article, 2017)
      Cuttings transport is a topic of great interest in the oil and gas drilling industry. Insufficient cuttings transport leads to several expensive problems. Knowledge and selection of the drilling fluids is one of the important ...
    • Laboratory Evaluation of Static and Dynamic Sag in Oil-Based Drilling Fluids 

      Ofei, Titus Ntow; Kalaga, Dinesh V.; Lund, Bjørnar; Saasen, Arild; Linga, Harald; Sangesland, Sigbjørn; Gyland, Knud Richard; Kawaji, Masahiro (Journal article; Peer reviewed, 2020)
      In this paper, we present the results of barite sag measurements before and after hot-rolled oil-based drilling fluids (OBDFs) using different approaches for characterization. We characterized the barite sag of a liquid ...
    • Use of Tracer Particles for Tracking Fluid Interfaces in Primary Cementing 

      Taheri, Amir; Ytrehus, Jan David; Taghipour, Ali; Lund, Bjørnar; Lavrov, Alexandre; Torsæter, Malin (Chapter, 2019)
      In this study, a new approach for detailed tracking of the interface between well fluid and cement by using particles is investigated. This can improve the quality of annular cementing of CO2 wells and thus the storage ...
    • 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 ...