DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

Technical Report · Wed Oct 01 04:00:00 EDT 2003

DOI:https://doi.org/10.2172/823034· OSTI ID:823034

Mohanty, Kishore K

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 conducted adsorption, phase behavior, interfacial tension (IFT) and wettability studies. Alfoterra-38 (0.05 wt%), Alfoterra-35 (0.05 wt%), SS-6656 (0.05 wt%), and DTAB (1 wt%) altered the wettability of the initially oil-wet calcite plate to an intermediate/water-wet state. Low IFT ({approx}10{sup -3} dynes/cm) is obtained with surfactants 5-166, Alfoterra-33 and Alfoterra-38. Plans for the next quarter include conducting wettability and mobilization studies.

• Research Organization: University of Houston (US)
• Sponsoring Organization: (US)
• DOE Contract Number: FC26-02NT15322
• OSTI ID: 823034
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
ADSORPTION
CALCITE
CARBONATES
ENHANCED RECOVERY
FRACTURED RESERVOIRS
FRACTURES
PLATES
SANDSTONES
SOLUBILITY
SURFACTANTS
WATERFLOODING
WETTABILITY