Open AccessDILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS
Author(s) -
Kishore K. Mohanty
Publication year - 2003
Language(s) - English
Resource type - Reports
DOI - 10.2172/815456
Subject(s) - carbonate , pulmonary surfactant , wetting , adsorption , brine , calcite , miscibility , petroleum engineering , geology , oil field , enhanced oil recovery , chemical engineering , mineralogy , materials science , chemistry , composite material , organic chemistry , engineering , metallurgy , polymer
There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have acquired field oil and core samples and field brine compositions from Marathon. We have conducted preliminary adsorption and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Receding contact angles increase with surfactant adsorption. Plans for the next quarter include conducting adsorption, phase behavior and wettability studies