Executive Summary : | Today, rapid accumulation of carbon dioxide (CO2) and other greenhouse gases (GHG), due to anthropogenic emissions, are raising concerns about the potential of global climate change. Furthermore, prevailing geopolitical conditions and technical constraints have forced nations, especially in developing country like India, to continue to rely on fossil fuels (coal, crude oil, and natural gas) to meet their surplus energy needs. However, Indian Government has committed to attain “net-zero” carbon footprint by 2070. To attain the vision of “net-zero”, bulk storage of captured CO2 is the most feasible way ahead and depleted brownfield reservoirs in Cambay are the most suitable sites due to their well-formed petrography, established fluid holding capacity, and injection infrastructure. Thus, in this work, CO2 interaction with actual rock samples will be understood in presence of oilfield surfactant and polymer (oil recovery methods) via high-pressure and high-temperature (HPHT) contact angle cell (Phase 1). Then, relative permeability of CO2 of different forms (gas/supercritical) will be determined using gas permeability cell at IIT Bombay (Phase 2). Next, the help of microfluidic unit will be taken to investigate pore-scale CO2 movement in fractured chips of reservoir equivalent pore throats of varying size and spatial distribution (Phase 3). This will be followed by field scale flow behavior and fluid displacement studies using an HPHT (10000 psia/150 oC) core-flooding unit, equipped with pressure differential, SCADA, and back pressure valve (Phase 4). The experimental results will be used to develop pore-scale mechanisms at work during CO2 injection and storage in subsurface environment of Cambay basin. To further improve our understanding of pore-scale mechanisms, an extensive simulation with standard molecular dynamics software (Gromacs) will be performed (Phase 5). The requirement of minimum miscibility enrichment (MME) and minimum miscibility pressure (MMP) for CO2-EOR would be established for reservoir conditions of Cambay basin utilizing a high pressure slim-tube setup (Phase 6). Finally, based on experimental and simulation data, a source-sink matching of proposed reservoir for net-zero scheme of carbon storage will be performed using geophysical parameters and modelling (Phase 7). Suitable agencies such as ONGC/Vedanta will be approached to obtain real field-reservoir samples for carbon storage/fluid displacement studies and to explore possibility of field implementation of proposed mechanisms of carbon storage in brownfield reservoirs of Cambay. |