Enhanced Oil Recovery Using Micron-Size Polyacrylamide Elastic Microspheres: Underlying Mechanisms and Displacement Experiments

Abstract

Micron-size polyacrylamide elastic microsphere (MPEM) is a newly developed profile control and oil displacement agent for enhanced oil recovery in heterogeneous reservoirs.In this study, laboratory experiments were performed to characterize the viscoelastic properties of MPEMs in brine water. A transparent sandpack micromodel was used to observe the microscopic flow and displacement mechanisms, and parallel-sandpack models were used to investigate the profile control and oil displacement performance using MPEMs in heterogeneous reservoirs. The results indicate that MPEMs almost do not increase the viscosity of injection water and can be conveniently injected using the original water injection pipelines. The microscopic profile control and oil displacement mechanisms of MPEMs in porous media mainly behave as selective-plugging in large pores, fluid diversion after MPEMs plugging, oil drainage caused by MPEMs breakthrough, and the mechanism of oil droplets converging into oil flow. MPEMs have a high plugging strength, which can tolerate a long-term water flushing. MPEMs can selectively enter and plug the large pores and pore-throats in high permeability sandpack, but almost do not damage the low permeability sandpack. MPEMs can effectively divert the water flow from the high permeability sandpack to the low permeability sandpack and improve the sweep efficiency of low permeability sandpack and low permeability area in the high permeability sandpack. The results also confirm the dynamic process of profile control and oil displacement using MPEMs in heterogeneous reservoirs.

Amido‐Amine‐Based Cationic Gemini Surfactants: Thermal and Interfacial Properties and Interactions with Cationic Polyacrylamide

“…Most of the literature suggests a representative shear rate of 7.3 s -1 for laboratory studies, as it is the typical reservoir shear rate [23]. It is well understood that the enhanced viscosity can increase the macroscopic displacement efficiency [37]. Recent studies have also found that the elasticity of a polymer can help in recovering residual trapped oil [38,39].…”

Study on a Novel Gelled Foam for Conformance Control in High Temperature and High Salinity Reservoirs

“…This high water cut in production wells has become a common problem in high temperature and high salinity oilfield developments [6][7][8]. Conformance control is widely used and has been proven to be an important measure to improve the efficiency of water flooding and enhance the oil recovery [9][10][11][12][13][14]. However, the lack of a suitable conformance control agent restricts the popularization and application of conformance control treatment in high temperature and high salinity reservoirs.…”

Preparation of poly(acrylamide‐co‐acrylic acid)/silica nanocomposite microspheres and their performance as a plugging material for deep profile control

“…They can be synthesized for crosslinked hydrophilic microspheres with excellent three‐dimensional networks and good flexibility which are valuable in oil development. There are some recent studies that have conducted pure polymer microspheres on the plugging properties of oil field depth profile control agents and their flow diversion effects . However, these pure organic hydrophilic polymers always show excessive swelling degree, low spherical degree, and weak shear resistance which are not beneficial for practical applications .…”

“…There are some recent studies that have conducted pure polymer microspheres on the plugging properties of oil field depth profile control agents and their flow diversion effects. 24,25 However, these pure organic hydrophilic polymers always show excessive swelling degree, low spherical degree, and weak shear resistance which are not beneficial for practical applications. 26 Moreover, the low dispersion of pure polymer microspheres also restricts their injection and migration in reservoir channels.…”