Distinct chemical and stable isotope compositions of smectite formed during steaming of Clearwater Formation oil-sands from Cold Lake, Alberta

Chemical reactions between oil-sands and injected steam or condensate during cyclic stimulation (CSS), commonly used to mobilize heavy oil bitumen, result in decomposition of pre-existing minerals formation new phases including clay minerals. These changes can reduce reservoir permeability limit hydrocarbon recovery. In this study, the chemical stable isotope compositions berthierine smectitic contained pre- post-steam Clearwater Formation from Cold Lake, Alberta were analyzed investigate how these affected by CSS. Berthierine abundance injection-zone decreased after steaming whereas increased. Pre- exhibited same range compositions, while those differed. Some injection-zone, particular, contain significantly more Fe Si but less Al than pre-steam samples. It is proposed that contributed CCS through partial inheritance 1:1 structure. This model approximates unique The also helps explain incomplete oxygen hydrogen exchange injection fluids formed