Adsorption of EOR Chemicals under Laboratory and Reservoir Conditions, Part 1 - Iron Abundance and Oxidation State

摘要: Surfactant adsorption is not just a primary economic impediment to chemical enhanced oil recovery (EOR), it has also been identified as leading uncertainty in forecasting (Anderson et al., 2006). This somewhat surprising, the basic phenomena controlling of anionic surfactants – at least on majority minerals present hydrocarbon reservoirs are well established (Gaudin and Fuerstenau, 1955; Cases 1982; Zhang Somasundaran, Nevertheless, EOR field trials have yielded results that diverge from lab measurements poorly-preserved cores by factor 2 6 (Wang, 1993). In this article, we attempt resolve discrepancies between reservoir measurements, continuing along lines investigation Wang (1993). The oxidation reduced iron materials may be linked increased several mechanisms: • Increased surface charge iron-containing clays upon oxidation; High specific area positively charged hydrous ferrous oxide (HFO) colloids; Higher iso-electric point (IEP) some oxidized with regards those found reservoir. Total’s mineralogical database queried determine typical content mineralogy, these add considerable detail sparse literature subject. Median around 1.2 wt%, although high 5 wt% catchment zones associated significant volcanism, below 0.1 carbonate formation. No evidence Fe(III) oil-bearing zones, including shallow, biodegraded region where immediately above zone, however methods used capable distinguishing Fe(II) clay minerals. Adsorption various presented order illustrate points listed above.