Low salinity cyclic water injection for enhanced oil recovery in Alaska North Slope

• Main Author: Kulathu, Sathish S.
• Format: Thesis
• Language: English
• Published: 2009
• Subjects: Enhanced oil recovery; Oil field flooding; Secondary recovery of oil; Arctic; Fairbanks; Alaska North Slope; north slope; Alaska
• Online Access: http://hdl.handle.net/11122/12804

Thesis (M.S.) University of Alaska Fairbanks, 2009 "Properties and flow pattern of injected water have an impact on properties like rock wettability and oil saturation. Researchers have observed increased oil recovery with low salinity brines and reduced water production with cyclic injection. Low salinity cyclic water injection is an interesting combination to be evaluated for further implementation. Two-phase water-oil flow experiments were conducted on cleaned and oil-aged sandstone cores in a core holder apparatus. At connate water saturation, modified Amott-Harvey tests were performed to study wettability. Cyclic waterfloods were conducted to recover oil. Residual oil saturation (Sor) was calculated after every step. The experiments were repeated with reconstituted brines of different salinity and Alaska North Slope (ANS) lake water. The effect of low salinity waterfloods and oil-aging on wettability alteration was studied. The results were compared with available data from conventional floods performed on the same cores. Cyclic floods were also tested for different pulse intervals. Conventional waterflooding was conducted on recombined oil-saturated cores at reservoir conditions. Faster reduction in Sor and additional oil recovery was observed consistently with low salinity cyclic injection. Oil-aging reduced water wetness of cores. Subsequent low salinity floods restored the water wetness marginally. Shorter pulses yielded better results than longer intervals"--Leaf iii Arctic Energy Technology Development Laboratory, U.S. Department of Energy