In this work, a novel, low molecular weight amphiphilic polymer (LAP) with high content of surface‐active functional groups was developed, and its effectiveness for emulsion‐based enhanced oil recovery (EOR) in relatively low permeability reservoirs was evaluated. The LAP polymer can potentially be synthesized on an industrial scale through a free radical polymerization reaction between acrylamide (AM), methyl acrylate (MAA), and the unsaturated surfactant monomer 2‐(acylamido)‐dodecane sulfonic acid (C12AMPS). The interfacial tension between 1000 mg L−1 LAP water solution and Bohai crude oil at 50 °C was reduced to a low value of around 0.2 mN m−1. Core flooding tests were also conducted to study the EOR potential and migration properties of LAP in porous media. The resistance and residual resistant factors of 1500 mg L−1 LAP solution were measured to be 51.0 ± 0.1 and 16.5 ± 0.1, respectively, suggesting LAP's great potential to be used for reservoir profile control. In addition, oil recovered from a three‐layer heterogeneous core by LAP solution was found to be comparable to that recovered using alkaline‐surfactant‐polymer (ASP) flooding. It is also worth mentioning that to accommodate different reservoir conditions, the molecular weight of LAP is adjustable by modifying the concentration of chain transfer agent, surfactant monomer, or initiator.

Low interfacial tension (IFT) drainage and imbibition are effective methods for improving oil recovery from reservoirs that have low levels of oil or are tight (i.e., exhibit low oil permeability). It is critical to prepare a high efficient imbibition formula. In this work, a novel 2,4,6‐tris(1‐phenylethyl)phenoxy polyoxyethylene ether hydroxypropyl sodium sulfonate (TPHS) surfactant was synthesized and evaluated for imbibition. Its structure was confirmed by Fourier transform infrared spectroscopy and the interfacial tension (IFT) of the crude oil/0.07% TPHS solution was 0.276 mN/m. When 0.1 wt% TPHS was mixed with 0.2 wt% alpha olefin sulfonate (AOS), the IFT was lowered to 6 × 10−2 mN/m. The synergy between nanoparticles (NPs) and TPHS/AOS mixed surfactant was studied by IFT, contact angle on sandstone substrates, zeta potential, and spreading dynamics through microscopic methods. The results show that the surfactant likely adsorbs to the NP surface and that NP addition can help the surfactant desorb crude oil from the glass surface. With the addition of 0.05 wt% SiO2 NPs (SNPs), the imbibition oil recovery rate increased dramatically from 0.32%/h to 0.87%/h. The spontaneous imbibition recovery increased by 4.47% for original oil in place (OOIP). Compared to flooding by TPHS/AOS surfactant solutions, the oil recovery of forced imbibition in the sand‐pack increased by 12.7% OOIP, and the water breakthrough time was delayed by 0.13 pore volumes (PV) when 0.05% SNPs were added. This paper paves the way for enhanced oil recovery in low‐permeability sandstone reservoirs using novel TPHS/AOS surfactants and SNPs.