Enhanced oil recovery using local alkaline
Improvement in productivity is one of the Oil and Gas industry’s biggest challenges. About 60% of crude Oil still lay trapped in the reservoir even after primary and secondary recovery process have been completed, hence the need for a method that further improves recovery. In this study, flooding experiment was conducted at laboratory condition to investigate the use of locally sourced alkaline in improving recovery on sand samples. The efficiency of the local alkaline (palm bunch ash) was compared with other conventional alkaline (NaOH, KOH, and Na2CO3). Eight cores (A1 – A$ and C1 – C4) were prepared, saturated with formation brine of 30, 000ppm salinity; crude (light and medium) were then flowed through sand samples. The samples were individually flooded with brine for secondary recovery process where an average of 55% of initial Oil in place was recovered. Each sample was flooded with different alkaline (local and conventional) for the tertiary recovery stage. The result obtained during flooding on samples saturated with light crude showed that KOH recovered 74%, NaOH recovered 66%, and palm bunch ash recovered an average of 64% while Na2CO3recovered 59%. It is recommended that the further studies to investigate the impact of the palm bunch ash should be carried out using heavy crude under reservoir conditions. These studies if successful will help and increase the use of local content which is relatively cheaper and this will in turn increase the local content drive of the Nigerian government in the oil and gas industry.
KEYWORDS: Secondary reservoirs, Flooding, Alkaline, Saturated, Samples, Brine, Local content, Enhanced recovery, Trapped.