Enhancement of CO₂ trapping efficiency in heterogeneous reservoirs by water‐alternating gas injection

Abstract

Carbon geosequestration efficiency is affected by various factors including reservoir heterogeneity, caprock properties, rock wettability, aquifer brine salinity and injection‐well configuration. Some parameters (e.g. the formation geology) cannot be changed but it is possible to select others and engineer an optimized storage program. One of these parameters is the way CO2 is injected into the reservoir. There are three main options for this: (1) continuous injection, (2) intermittent injection, and (3) water‐alternating gas (WAG) injection. We thus studied the efficiency of each injection option and predicted the associated storage capacities and CO2‐plume movements (which are related to the containment security). We found that WAG injection showed significantly superior behavior over continuous and intermittent injections (which resulted in similar CO2 flow responses). Specifically, residual and solubility trapping were significantly enhanced, whereas vertical CO2 migration was cut by approximately two‐thirds. Thus, in the examined reservoir, the WAG injection is preferred as it strongly enhances CO2 storage efficiency and containment security. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Numerical Simulation of the Influence of Geological CO2 Storage on the Hydrodynamic Field of a Reservoir

“…Reducing the emissions of carbon dioxide (CO 2 ) is a common challenge for countries worldwide [1]. The geological storage of CO 2 has attracted the attention of governments and scientists around the world as a direct and effective emission reduction method recognized by the international community [2][3][4][5]. Once the CO 2 has been transported, it is stored in porous geological formations that are typically located several kilometers below the Earth's surface, and under the pressure and temperature conditions of such reservoirs, CO 2 exists in a dense phase.…”

Water–rock–CO2 interactions and CO2 storage of Honghe tight oil reservoirs: an experimental and simulation study

“…According to the combination of measured water–rock interaction results and characteristic analysis of Honghe tight cores, we build a reservoir numerical simulation considering CO 2 , water–rock interaction, and permeable area lag to investigate the impact of such interactions on sweep efficiency and CO 2 storage, as previously done …”

Experimental Study on Relative Permeability Characteristics for CO2 in Sandstone under High Temperature and Overburden Pressure

“…The technology of CO 2 capturing and storage (CCS) [10,11], one of the direct and effective technologies to reduce CO 2 emissions and alleviate the greenhouse effect, captures CO 2 from large emission sources like thermal power plants and then transports it to designated positions (the ground or the seabed) for permanent storage [12,13]. Al-Khdheeawi et al [14][15][16][17][18][19][20][21][22][23][24][25][26] conducted some beneficial research in this regard. They investigated important effecting parameters on the CO 2 trapping capacity and CO 2 storage efficiency (e.g., CO 2 -rock wettability, reservoir heterogeneity, injection well configuration, salinity, relative permeability hysteresis).…”