Numerical investigation of basin-scale storage of CO2 in saline aquifers of Songliao Basin, China

摘要

This paper presents a basin-scale model study of the behaviors of CO2 plume and the potential environmental impacts for large-scale CO2 storage in the saline aquifers of Songliao Basin, China. The model covers the whole basin, and vertically consists of most of the Cretaceous strata. In a hypothetical scenario, a total of 1.43 GT CO2 is injected into the Yaojia Formation (K(2)y) through 20 wells distributing at the center of the basin in 50 years (0.5-2 million tons per injection well per year). The preliminary results show the permeable Yaojia Formation (K(2)y) with a thickness of 100-400 m at the center of the basin can store large amounts of CO2. The overlying Nenjiang Formation (K(2)n) with low permeability and large thickness has the potential to ensure long-term storage security. The high solubility of CO2 of the formation water in this continental basin is a favorable condition for the storage security. The maximum extent of the CO2 plume from different injection wells ranges from about 4 km to 20 km at 1000 years. The maximum pressure build-up in the Nenjiang Formation (K(2)n) and the Yaojia Formation (K(2)y) reaches 8.6 MPa and 9.3 MPa, respectively. An entry capillary pressure of 1 MPa may be enough for the caprock to seal CO2 in the large-scale CO2 storage. The mudstone layers in the Nenjiang Formation (K(2)n) can play a crucial role in restraining upward brine migration.(c) 2014 Society of Chemical Industry and John Wiley & Sons, Ltd