Enhancing ASP Flooding by Using Special Combinations of Surfactants and Starch Nanoparticles

Abstract

This study aimed to address the challenges faced by mature oilfields in extracting substantial oil quantities. It focused on improving the efficiency of alkaline–surfactant–polymer (ASP) flooding technique, which is a proven tertiary recovery technology, to overcome scaling issues and other hindrances in its large-scale implementation. Appropriate materials and their suitable concentrations were selected to enhance the ASP flooding technique. Special surfactants from Indonesia were introduced to improve the interfacial tension reduction and wettability alteration. Reservoir rock model that resembling Langgak oilfield in Sumatra was utilized, and low-salinity water was employed to mimic the oilfield conditions. Starches derived from cassava nanoparticles (CSNPs) and purple yam nanoparticles (PYNPs) were combined separately with conventional hydrolyzed polyacrylamide (HPAM) polymer to enhance its performance. Sodium hydroxide and sodium carbonate were used as alkaline in final ASP formula. It was demonstrated from this research that only two combinations of ASP formulations have led to improved oil recovery. One combination utilizing PYNPs resulted in 39.17% progressive recovery, while the other combination incorporating CSNPs achieved 35% incremental oil recovery. The ASP combination that resulted in recovery rate of 39.17% was composed of sodium hydroxide (NaOH) at a concentration of 1.28 wt.%, PSC EOR 2.2 (0.98 wt.%), and a combined polymer consisting of HPAM (0.2 wt.%) and PYNPs nano-starch (0.6 wt.%). The second combination led to 35% recovery rate and involved NaOH also at concentration 1.28 wt.%, PSC HOMF (0.63 wt.%), and a combined polymer comprising from HPAM (0.2 wt.%) and CSNPs nano-starch (0.8 wt.%). These findings of this study highlighted the potential of this modified ASP flooding to enhance oil recovery in mature oilfields, thereby offering valuable insights for oil industry.

Relation between Conventional and Starch-Assisted ASP Injection and Impact of Crystallinity on Flood Formation

“…It was found by Al-Jaber, H.A. et al [ 20 ] that the most effective combinations that resulted in higher oil recovery were specifically the combinations (NaOH—PSC EOR 2.2—(HPAM + PYNPs)), with an incremental oil recovery of 39.17%; (NaOH—PSC HOMF—(HPAM + CSNPs)), with an incremental oil recovery of approximately 35%; and also (NaOH—PSC HOMF—(HPAM + PYNPs)), which resulted of third higher recovery of about 34.61%. Therefore, these three combinations were selected for the conventional ASP flooding in this study, with the polymer component consisting solely of HPAM.…”

“…This indicates that the stability of HPAM molecules is better than the CSNPs combination, but the stability of PYNPs is better than the two (both HPAM and CSNPs). Therefore, PYNPs nano-polymer mixed with HPAM gave magnificent results in oil recovery experiments conducted by Al-Jaber et al [ 20 ]. The comparison reveals intriguing insights into the varying stability and surface charge among these two kinds of nanoparticles and HPAM.…”

“…To better understand these findings, a comparative analysis was conducted with the results reported by Al-Jaber, H.A. et al [ 20 ], as they explored the influence of CSNPs and PYNPs on ASP flooding.…”

“…The enhanced recovery achieved through ASP flooding with PYNPs can be attributed to the distinct properties of these nanoparticles. PYNPs possess a large surface area, allowing for better interaction with oil molecules and reservoir surfaces [ 20 ]. This enhanced interaction facilitates the displacement of trapped oil, leading to a higher recovery rate.…”

“…The results of such a chemical flooding are discussed in detail in research conducted by Al-Jaber, H.A. et al [ 20 ]. The current study is based on the comparison of this improved ASP flooding with traditional ASP flooding (without NPs), from which the polymer counterpart consisted only of HPAM.…”