Improving enhanced heavy oil recovery by pairing hot water with surfactant

Abstract

In the industry of oil and gas, the most important aspect that needs to pay attention is the production of oil and natural gas to maximize the profit of the well. However, it is a challenging process as the mobility of the crude oil is the main aspect that needed to deal with. Although the heavy oil can be recovered through water and surfactant injection, it is still not economically viable as the recovery rates are very low. In the present study, by pairing hot water with three type of surfactants, preferably alphaolefinsulfonates (AOS) and sodium dodecyl sulfate (SDS) of anionic group, a greater increase in the mobility of oil was seen, thus, increasing the recovery of the heavy oil. The first objective is studying the effect of pairing hot water and three type of surfactants to the viscosity and IFT by static condition tests. The second objective of this study is investigating the effect of pairing hot water with the surfactant in enhancing the heavy oil recovery by studying interfacial tension of heavy oil, surfactant and the reservoir rock thus determine the recovery rates of heavy oil when the interfacial tension decreased caused by the temperature of hot water and the presence of surfactants. Static tests were conducted to get a clear understanding on the mechanism by measuring the viscosity and interfacial tension between the heavy oil and injection fluid against heat (from room temperature to 60oC) and time and it is determined that the best surfactant between AOS and SDS is the first one. The recovery volume was measured at the dynamic condition by injecting the best saturation for each surfactant from the static test, with hot water into a core. This study showed that the maximum oil recovery for AOS is when the hot water temperature paired with AOS was at 50°C with 43.2% of oil recovery. Meanwhile, the maximum recovery for SDS is when the hot water temperature paired with SDS was at 60°C with 27.2% of oil recovery. In conclusion, it is shown that the heavy oil recovery of this mechanism is higher than that of pure hot water flooding or the surfactant flooding process.