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Háskóli Íslands > Verkfræði- og náttúruvísindasvið > Meistaraprófsritgerðir - Verkfræði- og náttúruvísindasvið >

Vinsamlegast notið þetta auðkenni þegar þið vitnið til verksins eða tengið í það: http://hdl.handle.net/1946/41440

Titill: 
  • Structural Analysis of a High Temperature Geothermal Well Cement
Námsstig: 
  • Meistara
Útdráttur: 
  • Útdráttur er á ensku

    This thesis aims to investigate failures of cement in a geothermal well, when subjected to high temperatures and pressure and how that affects the production casing when the cement loses mechanical strength. A three-dimensional thermal model was constructed to analyze the temperature distribution of the well and a three-dimensional structural model was made to evaluate the stresses and strains of the cement and the production casing. The critical area in the cement casing, where the couplings outside of the production casing interact with the cement, is
    the area of interest. The results, showed high principal stresses and strains in the cement, where edges of couplings interact with the cement at 350°C, 400°C and 450°C. The highest compressive stress at the critical area in the cement increases around 8% when the temperature is increased from 350°C to 450°C. The stresses and strains were also examined in the production casing at the same temperatures and compared
    to the yield strengths of the materials. The von Mises stresses in the steel casing decreased with increased temperature, the stresses in the steel casing reached the steel’s yield stress. The von Mises strains in the steel casing increased with increased temperature and were considered high. Different compression strength values for the cement were implemented in the model to analyze the stresses at the critical area since stresses in the cement can be limited by higher compression
    strength. A compression test on a cement sample from the IDDP-1 well showed a 51 MPa compression strength at room temperature. This compressive strength value resulted in a higher compressive stress value at the critical area in the cement when implemented in the model. Finally, different values of Young’s modulus for the cement were also examined at 450°C to estimate its effect on the stresses in the cement. The stresses and strains were considerably higher for both cement
    and steel casing when Young’s modulus was increased

Styrktaraðili: 
  • Styrktaraðili er á ensku
Samþykkt: 
  • 1.6.2022
URI: 
  • http://hdl.handle.net/1946/41440


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