Low-Tension Polymer Flooding Using a Short-Hydrophobe Surfactant for Heavy Oil Recovery

Abstract

Short-hydrophobe surfactants based on cosolvent species have been studied as novel surfactants for enhanced oil recovery. The objective of this research is to investigate such simple surfactants as a sole additive that enhances the efficiency of oil displacement by creating low-tension polymer (LTP) fronts. This paper presents the potential enhancement of oil displacement efficiency by LTP flooding based on comprehensive experimental data, such as interfacial tensions (IFTs), surfactant partition coefficients, surfactant adsorption in a sandpack, polymer/LTP rheology, and sandpack flooding results. The optimal LTP identified was composed of 0.5 wt % 2-ethylhexanol-7PO-15EO in partially hydrolyzed polyacrylamide polymer solution, which reduced the IFT with heavy oil from 15.8 to 0.025 dyn/cm, without creating microemulsions. The surfactant adsorption in the sandpack was only 0.055 mg-surfactant/g-sand. Sandpack flooding results show that the LTP flooding achieved an incremental oil recovery in comparison to straight-polymer flooding. The oil recovery at 1 pore-volume injected (PVI) was 47% original-oil-in-place (OOIP) for the polymer flooding, 63% for the smaller LTP slugs (0.5 wt % surfactant for 0.1 PVI and 0.1 wt % surfactant for 0.5 PVI), and 70% for the larger LTP slug (0.5 wt % surfactant for 0.5 PVI). Fractional flow theory was applied to confirm that the IFT reduction by 3 orders of magnitude was conducive to a lowered residual oil saturation in LTP flooding, leading to a delayed polymer breakthrough and an increased oil cut thereafter in comparison to polymer flooding.

Polymer Surfactant Interactions in Oil Enhanced Recovery Processes

“…Materials. A partially hydrolyzed polyacrylamide (HPAM) Floopaam of different molecular weights (3,6,14, and 18 million dalton) provided by SNF Floerger and sodium dodecyl benzene sulfonate (SDBS, technical grade, Sigma-Aldrich) were used in this research. Isobutanol (purity >99%), decane (99% purity), and sodium chloride (NaCl) (99.9% purity) were purchased form Merck.…”

“…A decontamination or enhanced oil recovery (EOR) procedure therefore requires an injection of a surfactant solution, followed by an injection of a polymer solution or the injection of a blend of polymers and surfactants. 6 In order to achieve this double task, surface active polymers 11 or nanoemulsions stabilized by surfactants have been studied. 12,13 Here, we focus on simpler systems: a mixture of polymers and surfactants designed to be injected at the same time.…”

“…When their mobility is less than the one of the oil in place, the interface front between the polymer solution and the oil in the porous media is stable, which allows a perfect sweeping of the reservoir. A decontamination or enhanced oil recovery (EOR) procedure therefore requires an injection of a surfactant solution, followed by an injection of a polymer solution or the injection of a blend of polymers and surfactants . In order to achieve this double task, surface active polymers or nanoemulsions stabilized by surfactants have been studied. , …”

A Role for Newly Developed Sorbents in Remediating Large‐Scale Oil Spills: Reviewing Recent Advances and Beyond

“…Viscous oil, also known as heavy crude oil, has been an especially persistent problem in oil spill remediation. [239][240][241][242][243][244] Heavy Figure 10. A) From macroscopic assembly of micro/nano building blocks to emerging applications.…”

Effect of Ligand Structure on the Kinetics of Heavy Oil Oxidation: Toward Biobased Oil-Soluble Catalytic Systems for Enhanced Oil Recovery

“…However, the main limitation of this type of oils is their high viscosity and density, which challenge and complicate their exploitation and production. − Therefore, research on enhanced heavy oil recovery (EOR) methods is essential to increase the rate of heavy oil production on one hand and on the other hand to improve the quality of the obtained oil as well . Until now, water injection, chemical injection, gas, and thermal injection have been considered the main proposed methods in the field of EOR. ,,,− However, thermal methods are widely believed to be the most important enhanced oil recovery methods in terms of the produced oil quality and economic aspects. According to the literature, in situ combustion (ISC) as a subset of the thermal injection method has been always considered as an effective and appropriate technology, especially when it comes to heavy oil reservoir exploitation. − Basically, this technology consists mainly of air injection into the reservoir under high pressure to provide the necessary conditions for initiating oxidation reactions and promoting a stable combustion flame front for a better oil recovery factor.…”