• An Experimental and Numerical Study of Hydraulic Pressure Loss and On-Set of Turbulence 

      Aarsland, Sindre Eiane (Master thesis, 2013)
      AbstractA long drillstring consists of numerous of diameter changes, where the most frequent is the change due to tool joints for every pipe length. In the upper wellbore sections, were the annular clearance are wide, are ...
    • Analysing Complex Oil Well Problems through Case-Based Reasoning 

      Abdollahi, Jafar (Doktoravhandlinger ved NTNU, 1503-8181; 2007:225, Doctoral thesis, 2007)
      The history of oil well engineering applications has revealed that the frequent operational problems are still common in oil well practice. Well blowouts, stuck pipes, well leakages are examples of the repeated problems ...
    • Analysis of Hook load Signal to reveal the Causes of Restrictions 

      Glomstad, Tina Svensli (Master thesis, 2012)
      Wells that are drilled today are becoming deeper and more complex, and actions to make these wells economically justifiable are desired by oil companies. One method is to reduce the non-productive time during drilling by ...
    • Analysis of Stick-Slip Effects During Oil-Well Drilling 

      Zhao, Dapeng (Doctoral theses at NTNU;2017:127, Doctoral thesis, 2017)
      The drilling operation is a costly portion of the upstream petroleum industry. It is worth making efforts to reduce unwanted non-productive time (NPT), which is often induced by downhole problems during drilling. In this ...
    • Building, Testing and Qualifying New Hook Load Rig 

      Sjøberg, Asgeir Sogge (Master thesis, 2014)
      To meet the growing demand for energy, the petroleum industry is looking in places previously thought to be unreachable. The continued search is causing the oil and gas industry to drill more advanced wells than ever. With ...
    • Cement Displacement Efficiency in Rough Pipes 

      Johansen, Espen; Giil, Gunnar Lia (Master thesis, 2017)
      Research within casing string cementing is important in the oil industry. The integrity of an oil well is dependent on the quality of the cement job, and a poor cement job can put the environment, company economics and ...
    • Cement Displacement Efficiency in Smooth and Rough Pipes - An Experimental and Theoretical Investigation 

      Mehari, Mehari Redae (Master thesis, 2016)
      Researches in the industry have always ascertained that mud channels affect the two principal objectives of primary cement job; zonal isolation and structural support. This can lead to envi- ronmentally, operationally ...
    • 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 ...
    • Cement sheath modification using nanomaterials for long-term zonal isolation of oil wells: Review 

      Jafariesfad, Narjes; Geiker, Mette Rica; Gong, Yi; Skalle, Pål; Zhang, Zhiliang; He, Jianying (Journal article; Peer reviewed, 2017)
      Well cementing is an important operation during drilling and completion of oil wells. The cement sheath must maintain well integrity behind the casing and provide long-term zonal isolation to ensure safety and prevent ...
    • CEMENTING THE 20 INCHES SURFACE CASING 

      Tembo, Carlos Buinga (Master thesis, 2014)
      The placement of cement in annulus behind the casing is a important operation in an oil well s life. To ensure zonal isolation, the fluid in place in the annulus has to be completely displaced by the slurry. Poor excess ...
    • Cuttings Bed Erosion 

      Isgandarzada, Adil (Master thesis, 2017)
      The growth of cuttings beds in horizontal and highly inclined wells in the wellbore is one of the main problems in oil and gas industry. The main purpose of this project is to find the flow velocity at which the erosion ...
    • Cuttings Bed Erosion in Horizontal Wells 

      Ganga, Hugo Alexandre Machado (Master thesis, 2016)
      Many of the time consuming and economically demanding drilling problems faced today can be tracked back to poor hole cleaning, even more so when drilling through highly inclined sections. Improved hole cleaning operations ...
    • Cuttings Transport in Inclined Sections 

      Kosberg, Birgitte Ruud (Master thesis, 2017)
      Mud rheology is a key parameter in hole cleaning efficiency. Field data suggests that oil-based drilling fluids perform better compared to water based drilling fluids in the field, even with identical rheological properties, ...
    • Design of Laboratory Procedures for General exercises and for Research Investigation. 

      Godwin, Young Godwin (Master thesis, 2013)
      I used existing laboratory guides from other universities to create educational laboratory modules related to reservoir, drilling and production engineering research based on existing equipment in the petroleum laboratory ...
    • Detection of Conglomerate Formations While Drilling 

      Nilsen, Ulrikke (Master thesis, 2015)
      The high drilling cost of today s oil and gas industry makes drilling optimization highly desirable. Lost time during drilling caused by unforeseen challenges is common, and increases well cost. The elimination of such ...
    • Diagnosing Root Causes and Generating Graphical Explanations by Integrating Temporal Causal Reasoning and CBR 

      Nikpour, Hoda; Aamodt, Agnar; Skalle, Pål (Journal article; Peer reviewed, 2017)
      This study proposes a methodology to diagnose the root causes of failures in the domain of oil well drilling. The idea is to combine a Bayesian network, which is generated based on an expert knowledge, with situation-specific ...
    • Downhole failures revealed through ontology engineering 

      Skalle, Pål; Aamodt, Agnar (Peer reviewed; Journal article, 2020)
      Frequency of failures occurring during offshore oil-well drilling do not diminish over time, probably due to increased operational complexity. The volume and frequency of information generated during the drilling process ...
    • Drillability in real-time. 

      Richardsen, Martin Lagesen (Master thesis, 2013)
      The formation drillability is an elusive parameter. For theoretical consideration it considered constant and given a value which is representative for the drillability for formations in the Mexican Gulf. The drillability ...
    • Drillpipe Rotation Effects on Pressure Losses 

      Skjold, Thorbjørn Lejon (Master thesis, 2012)
      Keeping control of the downhole pressure is important in any drilling situation, and especially when a narrow pressure window is experienced. The equivalent circulation density is influenced by rotation of the drillpipe, ...
    • Evaluation of Rheology and Pressure Losses for Oil-based Drilling Fluids in a Simulated Drilling Process 

      Assembayev, Dias Viktorovitsj (Master thesis, 2015)
      The advancements in the field of hydraulics have indicated that eccentricity in the well greatly reduces the pressure losses. This knowledge has been readily adopted in the industry practice, but the theoretical approximations ...