Advances of polymer microspheres and its applications for enhanced oil recovery.

After long-term water injection, mature reservoirs are encountered with the adverse consequences of the treatment, including erosion, rock formation destruction and drastic decline in oil recovery rate for the past years. Today, the inexpensive and highly efficient polymer microspheres can be considered as a solution to the current issue with excess water production. Studies on practical utilization of polymer microspheres to plug high-permeability zones in heterogeneous reservoirs gained immense popularity in oil production lately.

On the effects of organic-acids isomers on temperature-responsiveness in wormlike micelles (WLMs) systems.

Responsive wormlike micelles (WLMs) consisted of cationic surfactants and organic-acids are fascinating due to their reversible molecular recognition properties. However, it is unknown how the structure of organic-acids alters the stimuli-responsiveness of WLMs systems. Herein, the peculiar nature of temperature-responsive behaviors in three WLMs systems were systematically investigated.

Advances of microemulsion and its applications for improved oil recovery.

Microemulsion, because of its excellent interfacial tension reduction and solubilization properties, has wide range of applications in the petroleum industry, especially in improved oil recovery (IOR). Herein, the concept, types and formation mechanism of microemulsion were primarily introduced. Then, the preparation and characterization methods were illustrated.

An Advanced Material with Synergistic Viscoelasticity Enhancement of Hydrophobically Associated Water-Soluble Polymer and Surfactant.

In order to prepare materials with controllable properties, changeable microstructure, and high viscoelasticity solution with low polymer and surfactant concentration, a composite is constituted by adding surfactant (sodium dodecyl sulfate, SDS) to hydrophobically associated water-soluble polymer (abbreviated as PAAC) solution. The viscoelasticity, aggregate microstructure, and interaction mechanism of the composite are investigated by rheometery, Cryo-transmission electron microscopy (Cryo-TEM), and fluorescence spectrum. The results show that when the mass ratio of polymer to surfactant is 15:1, the viscosity of the composite reaches the maximum.

Progress of polymer gels for conformance control in oilfield.

For the past decades, long-term water flooding processes have led to water channeling in mature reservoirs, which is a severe problem in oilfields. The development of better plugging ability and cost-effective polymer gel is a key aspect for the control of excess water production. Research on polymer gel applicable in a heterogeneous reservoir to plug high permeable channels has been growing significantly as revealed by numerous published scientific papers.

The advances of organic chromium based polymer gels and their application in improved oil recovery.

In recent years, with the further development of old oilfields, in order to further improve the oil recovery, they must be conformance controlled. Among various types of conformance control methods, polymer gels composed of polymers and crosslinkers have attracted widespread attention because of their efficiency and low costs. Among them, organic chromium gels with their good formation adaptability and high stability have been fully developed in recent decades.