Characterization of Rock and Fluid Properties for Low-Salinity Water Flooding of Highly Paraffinic Oil in a Deep Low-Permeability High-Pressure High-Temperature Offshore Carbonate Reservoir

Abstract

Characterization of the rock and fluids is an essential step in screening a reservoir for Low-Salinity Water Flooding (LSWF). A detailed characterization of rock and fluid properties using appropriate methods is being presented for LSWF in a low-permeability deep carbonate reservoir together with a critical analysis of findings. The techniques used are assessed against other possible alternative methods, with inferences drawn on advantages and disadvantages of each to better interpret and apply data so gathered. In so doing, discussions on their key features as to how they can be used effectively and efficiently to screen a reservoir for LSWF are also provided. Such integration of results with other available reservoir and production data should result in a comprehensive description of the target reservoir, and it will help interpret the mechanisms and process dynamics more reliably during a low-salinity waterflood. This integration should allow us not only to gain confidence on the experimental studies but could also help optimize the key parameters responsible for formulating a more robust, reliable and representative regime for tests relevant to the LSWF prior to its eventual implementation in the field. To authors’ knowledge, such integration of experimental studies has not yet been reported in the literature, particularly for the tight carbonate reservoirs with highly paraffinic oil.

Role of Monovalent and Divalent Ions in Low-Salinity Water Flood in Carbonate Reservoirs: An Integrated Analysis through Zeta Potentiometric and Simulation Studies

“…The acid number of the oil is~0.6 mg KOH as reported by Kakati et al [18]. For same set of rock and oil samples, Singh et al [19] had conducted a contact angle measurement using sessile drop method which showed a very weak water-wet state with seawater (contact angle of~102 • ). This also correlates with the high acid number of oil.…”

“…The acid number of the oil is ~0.6 mg KOH as reported by Kakati et al [18]. For same set of rock and oil samples, Singh et al [19] had conducted a contact angle measurement using sessile drop method which The component analysis of oil samples was analyzed from ASTM D2887 simulated distillation. The C7+ hydrocarbon component proportions obtained from the analyses were combined into one component as given in Table 5.…”