Synthesis and Application of Hydrophilic Polymer Nanoparticles for Water Shut-Off

Abstract

Over the last few years, oil companies have devoted much effort to decrease the amount of water that is pumped up with oil, especially from mature reservoirs, where the water production is huge. In addition to reducing the profit margin, the water extracted from an oil field is polluted by different organic and inorganic compounds and must be properly treated before being discharged or reinjected. Alternatively, it must be disposed of with high treatment and/or disposal costs. To overcome costs associated with water treatment/disposal, mechanical and chemical strategies aimed at reducing the amount of extracted water (i.e., water shut-off) are applied. Among them, hydrophilic polymeric micro-and nanogels are promising materials that are gaining increasing interest. They are three-dimensional networks able to retain water by increasing in size and thus creating a physical barrier to the water flowing. In this work, nano-and microabsorbent particles made up of crosslinked poly(methacrylic acid-co-oligo(ethylene glycol) methyl ether methacrylate) p(MAA-co-OEGMA) were synthesized via inverse suspension polymerization in Lamix, an aromatic-free hydrocarbon blend. The formulation was optimized in terms of OEGMA mole fraction to achieve a high swelling in seawater and hence high efficacy in the water shut-off. Finally, the suspension was modified to be produced on a ton scale and injected into an open-hole, partially depleted oil reservoir for a first pilot field test. One-year monitoring was conducted by evaluating the oil productivity as well as the water fraction (i.e., water cut) under conventional extraction procedures. This trial assessed a 30% decrease in the water cut, as well as an increase in the oil production from 5 to 30 m 3 /day. This confirmed the developed microgels as a promising tool for water shut-off.

Role of the Polymer Microstructure in Controlling Colloidal and Thermo-Responsive Properties of Nano-Objects Prepared Via RAFT Polymerization in a Non-polar Medium

“…A rational design of the copolymer microstructure, involving parameters specific for both the solvophilic and solvophobic portions, is therefore crucial for developing materials with very specific properties and suitable for advanced applications. Indeed, polymeric nano-objects in non-polar media have already been successfully applied as oil emulsifiers, 6 water shut-off systems, 52 and lubricant additives. 23 The addition of the thermo-responsive behavior to these traditional materials would further expand their scope, allowing these fields to advance toward previously unimaginable horizons, as it already happened in the biomedical field, where thermo-responsive polymers are acting as the main drivers for innovation in tissue engineering and drug delivery.…”