The impact of reservoir conditions on the residual trapping of carbon dioxide in Berea sandstone

Abstract

The storage of carbon dioxide in deep brine-filled permeable rocks is an important tool for CO 2 emissions mitigation on industrial scales. Residual trapping of CO 2 through capillary forces within the pore space of the reservoir is one of the most significant mechanisms for storage security and is also a factor determining the ultimate extent of CO 2 migration within the reservoir. In this study we have evaluated the impact of reservoir conditions of pressure, temperature, and brine salinity on the residual trapping characteristic curve of a fired Berea sandstone rock. The observations demonstrate that the initial-residual characteristic trapping curve is invariant across a wide range of pressure, temperature, and brine salinities and is also the same for CO 2 -brine systems as a N 2 -water system. The observations were made using a reservoir condition core-flooding laboratory that included high-precision pumps, temperature control, the ability to recirculate fluids for weeks at a time, and an X-ray CT scanner. Experimental conditions covered pressures of 5-20 MPa, temperatures of 25-50 C, and 0-5 mol/kg NaCl brine salinity. A novel coreflooding approach was developed, making use of the capillary end effect to create a large range in initial CO 2 saturation (0.15-0.6) in a single coreflood. Upon subsequent flooding with CO 2 -equilibriated brine, the observation of residual saturation corresponded to the wide range of initial saturations before flooding resulting in a rapid construction of the initial-residual curve. For each condition we report the initial-residual curve and the resulting parameterization of the Land hysteresis models.

Capillary trapping for geologic carbon dioxide storage – From pore scale physics to field scale implications

“…A recent review of the subject (Iglauer et al, 2014a) highlights the challenging nature of these experiments and summarises that the wide range of behaviour observed can be attributed largely to differences in surface roughness and surface contamination between studies. Recent work reported in Niu et al (2015), and discussed in further detail in the next section clearly demonstrate that these effects do not manifest in the IR curve for a sandstone, which remains constant across a wide range of test conditions. Recent work focused on CO 2 storage has summarised the residual trapping relationship with a single value, the residual trapping efficiency, R = S CO 2 ,r /S CO 2 ,i (Akbarabadi and Piri, 2013;Bachu, 2013;Burnside and Naylor, 2014).…”

A Study of Residual Carbon Dioxide Trapping in Sandstone

“…After the completion of residual trapping experiment, the drainage and inhibition relative permeability curves have been measured on the same sample at 10MPa and 50 o C by using steady state experimental method with the same experiential setup. More details on experimental procedures can be found in other paper [9]. Figure 5 shows experimental data and fitted curve by using Brooks-Corey model, as in equations 5 and 6.…”

“…Injection rates 0.2cc/min and 20cc/min were chosen as optimum injection rates for CO 2 injection, and the corresponding imbibition rates were 0.2cc/min and 0.5cc/min respectively. More details on simulation model and optimum injection rates are available in reference [9]. Based on the simulated CO 2 saturation profile, the model from Spiteri et al [10] was used to predict residual CO 2 saturation, Where S gi and S gr are initial and residual gas saturation respectively.…”

The role of capillary trapping during geologic CO2 sequestration

“…Iglauer et al [10] studies suggest that the maximum storage capacity is achieved when the deposit porosity equals 20-30%. The lower the porosity, the smaller the geometric space for fl uids.…”

“…For geologic carbon sequestration, two diff erent displacement regimes, namely drainage and imbibition, are observed [7][8][9][10][11]. Drainage refers to the decreasing saturation of a wetting phase.…”