• Can Heating Induce Borehole Closure? 

      Xie, Xiyang; Bauer, Andreas; Stenebråten, Jørn; Bakheim, Sigurd; Lavrov, Alexandre; Fjær, Erling; Kristiansen, Tron Golder (Peer reviewed; Journal article, 2020)
      The current study shows that heating a cased borehole in low-permeability shale rock can induce plastic deformation, leading to the closure of the casing annulus and decreasing annulus connectivity. The thermally induced ...
    • Can heating-induced creep result in shale barriers for P&A applications? 

      Bauer, Andreas Kurt Marcel; Stenebråten, Jørn; Li, Liming; Fjær, Erling (Chapter, 2017)
      It has been shown that some shale formations form barriers around a casing of a well due to shale creep that results in closure and sealing of the annulus around the casing. The existence of such shale barriers facilitates ...
    • Comparing mechanical and ultrasonic behaviour of a brittle and a ductile shale: Relevance to prediction of borehole stability and verification of shale barriers 

      Holt, Rune Martin; Larsen, Idar; Fjær, Erling; Stenebråten, Jørn (Peer reviewed; Journal article, 2019)
      Borehole collapse during drilling operations in shale formations is a well-known and costly problem within the petroleum industry. Recently it has become evident that shales may also form sealing barriers around the casing, ...
    • Experimental Studies of Stress Dependence,Static vs Dynamic behaviour and Mechanical Anisotropies of Shale 

      Holt, Rune Martin; Bakk, Audun; Bauer, Andreas; Fjær, Erling; Stenebråten, Jørn (Chapter, 2014)
      Laboratory data from controlled rock mechanical tests with various shales have been used to understand and quantify stress effects on wave velocities of relevance for 4D seismics, and to quantify the difference between ...
    • Measurements of Young's Modulus on Rock Samples at Small Amplitude and Low Frequency: RockHard Deformations 

      Fintland, Trygve Westlye (Master thesis, 2011)
      This thesis describes a new instrumental approach designed to measure the complex Young s modulus on cylindrical samples 1 inch in diameter 2 inch long and typically in the range of 1-70 GPa. Excitation frequencies are ...
    • Overburden geomechanical effects on 4D seismic response - influences of stiffness contrast, anisotropy, and geometry 

      Li, Liming; Bauer, Andreas; Holt, Rune Martin; Fjær, Erling; Stenebråten, Jørn; Bakk, Audun (Journal article; Peer reviewed, 2014)
      Petroleum production and CO2 storage induce effective stress changes and deformations in the reservoir, as well as in the overburden. This may be detected by 4D seismic monitoring due to the stress-sensitivity of the seismic ...
    • Relating Static and Dynamic Mechanical Anisotropies of Shale 

      Holt, Rune Martin; Bauer, Andreas; Fjær, Erling; Stenebråten, Jørn; Szewczyk, Dawid; Horsrud, Per (Chapter, 2015)
      Experimental studies of shale cores of different orientations have been performed to compare the angular dependence of dynamic moduli acquired at ultrasonic frequencies with static moduli (Young’s moduli and Poisson ratios) ...
    • Skempton's A – A key to man-induced subsurface pore pressure changes 

      Holt, Rune Martin; Bakk, Audun; Stenebråten, Jørn; Bauer, Andreas; Fjær, Erling (Chapter, 2018)
      Fluid production from or injection into a subsurface reservoir leads to stress pressure changes inside and outside the reservoir. The overburden often consists of low permeability shale, and the undrained pore pressure ...
    • SPE-174356-MS Effect of Rock Anisotropy on Integrated Modelling 

      Li, Liming; Bakk, Audun; Fjær, Erling; Bauer, Andreas; Stenebråten, Jørn; Holt, Rune Martin (Chapter, 2015)
      Associated with reservoir monitoring towards optimizing production of oil and gas and maximizing the recovery, or ensuring safe CO2 storage, it may be beneficial to introduce integrated geomechanics, rock physics and seismic ...
    • Static and Dynamic Characterization of a Deep Overburden Shale 

      Bakk, Audun; Stenebråten, Jørn; Lozovyi, Serhii; Bauer, Andreas; Sønstebø, Eyvind Frode; Fjær, Erling; Bhuiyan, Mohammad Hossain; Chakraborty, Samarjit; Holt, Rune Martin (Chapter, 2018)
      Since shales are the far most abundant overburden formation, understanding the geomechanical and rock physics behavior of shales is essential. We discuss a particular deep overburden shale in light of a thorough static and ...
    • Stress sensitivity of velocities in anisotropic rocks - Rock models comparison and true-triaxial apparatus description 

      Duda, Marcin (Master thesis, 2017)
      The purpose of this study was to investigate the effects of anisotropy on elastic parameters of rocks, and to compare various types of anisotropic rock models with the use of ultrasonic data obtained with a true-triaxial ...
    • Stress-Induced Fracturing of Reservoir Rocks: Acoustic monitoring and uCT Image Analysis 

      Pradhan, Srutarshi; Stroisz, Anna Magdalena; Fjær, Erling; Stenebråten, Jørn; Lund, Hans Karl; Sønstebø, Eyvind Frode (Journal article, 2015)
      Stress-induced fracturing in reservoir rocks is an important issue for the petroleum industry. While productivity can be enhanced by a controlled fracturing operation, it can trigger borehole instability problems by ...
    • Thermally Induced Compaction of Shales 

      Bauer, Andreas; Holt, Rune Martin; Stenebråten, Jørn; Sønstebø, Eyvind Frode; Marøen, Leni Larsen (Chapter, 2014)
      Thermally-induced, non-reversible compaction with volumetric strains of up to more than 1% has been observed in laboratory compaction tests with core plugs of several different shales. While thermallyinduced compaction is ...