Carbon geosequestration in limestone: Pore-scale dissolution and geomechanical weakening
MetadataShow full item record
© 2017 Elsevier Ltd Carbon dioxide geosequestration in deep saline aquifers or oil and gas reservoirs is a key technology to mitigate anthropogenic greenhouse gas emissions. Porous carbonate rock is a potential host rock for CO 2 storage; however, carbonate rock chemically reacts when exposed to the acidic brine (which is created by the addition of CO 2 , CO 2 -saturated brine). These reactive transport processes are only poorly understood, particularly at the micrometre scale, and importantly how this affects the geomechanical rock properties. We thus imaged a heterogeneous oolitic limestone (Savonnières limestone) core before and after flooding with brine and CO 2 -saturated brine at representative reservoir conditions (323 K temperature, 10 MPa pore pressure, 5 MPa effective stress) in-situ at high resolutions (3.43 µm and 1.25 µm voxel size) in 3D with an x-ray micro-computed tomograph; and measured the changes in nano-scale mechanical properties induced by acid exposure. Indeed the carbonate rock matrix partially dissolved, and absolute and effective porosity and permeability significantly increased. This dissolution was confined to the original flow channels and inlet points. Importantly, the rock matrix weakened significantly (- 47% in indentation modulus) due to the acid exposure.
Showing items related by title, author, creator and subject.
Sari, Ahmad; Xie, Sam; Chen, Yongqiang; Saeedi, Ali; Pooryousefy, Ehsan (2017)Wettability alteration appears to be the main mechanism of low salinity water flooding in carbonate reservoirs. However, what factor(s) controls the wettability alteration is not clearly defined. We hypothesized that zeta ...
pH effect on wettability of oil/brine/carbonate system: Implications for low salinity water floodingXie, Sam; Sari, A.; Pu, W.; Chen, Y.; Brady, P.; Al Maskari, N.; Saeedi, Ali (2018)© 2018 Elsevier B.V. Wettability of oil/brine/carbonate system is a critical parameter to govern subsurface multi-phase flow behaviour, thus remaining oil saturation and ultimate oil recovery in carbonate reservoirs. ...
Lisk, Mark (2012)A comprehensive examination of the hydrocarbon charge and formation water history of the central Vulcan Sub-basin, Timor Sea has been completed and a model developed to describe the evolution of the region’s petroleum ...