The shearing effect on hydrophobically associative water‐soluble polymer and partially hydrolyzed polyacrylamide passing through wellbore simulation device

Abstract

Hydrolyzed polyacrylamide (HPAM) was the traditional polymer and hydrophobically associative water-soluble polymer (HAWP) was the new polymer with three-dimensional network both used to flood to enhance oil recovery. The wellbore area was the most important part before the polymer solution injected into stratum. In this article, the shearing effects of the two polymers were studied by a wellbore simulation device. The viscosities of HPAM and HAWP solutions were both decreased around perforation of wellbore simulation device. Interestingly, viscosity of HAWP recovered from stratum 0.2 m. Until stratum 1.6 m, its viscosity recovered almost 50% of original. The data of intrinsic viscosity showed that the molecular chains of HAWP and HPAM were both degraded without any recovery. The contradiction was further studied by particle size and its microstructure. The mean particle size and particle size distribution data both showed HAWP recovered but HPAM was not. The microstructures of HAWP by atomic force microscopy images further explain the recovery of viscosity. The disassembled molecular chain was self-assembled into aggregate to newly network by hydrophobes with weaker linking than original solution. While the microstructure of HPAM was thoroughly split up to randomly coil without linking. In addition, the viscoelasticity of HAWP was also recovered to some extent but HPAM was not. All the results proved that HAWP has mobility control ability to displace oil in reservoir even if suffered severely shearing by wellbore.

Interaction between Aqueous Solutions of Hydrophobically Associating Polyacrylamide and Dodecyl Dimethyl Betaine

“…For the AFM measurements, 0.1 mL of the prepared polymer-surfactant mixed system was dropped onto freshly cleaved mica, and the redundant solution was blown off by a stream of high purity nitrogen. Samples were measured by Nanoscope IIIa microscope in air at the ambient temperature [30].…”

Synthesis, Characterization, and Property Evaluation of a Hydrophobically Modified Polyacrylamide as Enhanced Oil Recovery Chemical

“…The polymer with three-dimensional network (ANOB) can reform network at slower shearing rate by self-assembly of hydrophobic groups. [18] Thus, the viscosity of ANOB solution can recover efficiently. It can be inferred that the sheared ANOB solution can also be used to flood in oilfields.…”

“…[18] Thus, the apparent viscosity was adopted as the main index for evaluation of rheological properties of polymer. Figure 6 presents the apparent viscosity changes of polymer solutions with temperature under a definite concentration of 1000 mg/L.…”

New Insights into the Mechanism of Mobility Reduction by Associative Type Copolymers

“…A different HMC based on an aromatic hydrophobe is discussed by Zhang et al (Zhang et al 2011). The shearing effect during injection of a HMC compared to a standard APAM was studied with simulation techniques (Zhang et al 2013). In this evaluation it was shown that APAM is shear degraded seriously, while the HMC is also degraded to a certain extent, but recovers after the shear had stopped and maintains a good performance.…”