Geologic CO2 storage site selection requires reservoir, seal, and overburden investigation to prevent injection- and storage-related risks. Three-dimensional geomechanical modeling and flow simulation are crucial to evaluate these mechanical-failure-related consequences; however, the model input parameters are limited and challenging to estimate. This study focuses on geomechanical properties extracted from seismic-derived elastic property cubes. The studied reservoirs (Middle Jurassic Sognefjord, Fensfjord, and Krossfjord formation sandstones) and cap rocks (Heather and Draupne formation shales) are located in the Smeaheia area, northern North Sea, and are evaluated for a potential CO2 storage site. From the elastic property cubes, i.e., acoustic impedance, P- to S-wave velocity ratio, and bulk density, we obtained geomechanical property cubes of Young's modulus, Poisson's ratio, shear modulus, lambda-rho, and mu-rho. Petrophysical property cubes such as porosity and shale volume were also available and were extracted from the elastic property cubes using deterministic methods. We evaluated the geomechanical properties to observe their relationship with depth, compaction/cementation, and petrophysical properties to characterize the cap and reservoir rocks. We found good coherence between the geomechanical and petrophysical properties and their relationship with compaction as a function of depth. The brittleness analyses using elastic property crossplots reveal that both the cap and reservoir rocks are mainly ductile to less ductile, posing lower fracturing risk during CO2 injection. This also indicates lower risks of associated microseismic and possible CO2 leakage.

Bangladesh is a riverine country where arsenic bearing silt and sediments coming from Himalayas gets deposited in the groundwater aquifers at different locations of Bangladesh. Groundwater is the most dependent form of sources for drinking in this area, unfortunately arsenic is of extensive amount (more than 50 ppb) found in this groundwater. Fourteen water samples from different depth of tube well, 8 soil samples from topsoil (15 cm) and subsurface (30 cm) and 7 different types of food materials were collected from Alampur Village, Amjhupi Union at Megerpur district. Water samples are preserved by HNO3 for maintaining pH (2-3). Food and food materials were digested with HNO3-H2SO4 in order to determine the arsenic by Ag-DDTC, UV-visible method. The arsenic of tube well water was beyond the Bangladesh acceptable limit and arsenic in food materials were with the limit of Australian food hygiene limit (1 mg /kg). Concentration of arsenic in topsoil (15 cm) was higher than arsenic in the subsurface (30 cm). The values of arsenic in food materials was lower, which indicated that arsenic from tube well water is adsorbed in soil but not to propagate food materials. It might be due to the type of soil.

No abstract

No abstract

No abstract