Synthesis and Performance Evaluation of a Novel Nanoparticle Coupling Expanded Granule Plugging Agent.

Area of Science:

• Petroleum Engineering
• Materials Science
• Chemical Engineering

Background:

• Fractured and vuggy reservoirs in high-temperature and high-salt environments, such as the Tahe Oilfield, present unique challenges for enhanced oil recovery.
• Existing polymer gel plugging agents often suffer from instability and complex preparation/transportation processes under harsh reservoir conditions.

Purpose of the Study:

• To develop and evaluate a novel nanoparticle coupling expanded granule plugging agent with enhanced stability and performance for high-temperature and high-salt oilfield reservoirs.
• To optimize the composition and preparation of the plugging agent, focusing on nanoparticle integration and granule formulation.

Main Methods:

• Synthesis of a novel nanoparticle coupling polymer gel using Acrylamide/2-acrylamide-2-methylpropanesulfonic copolymer salt and hydroquinone/hexamethylene tetramine crosslinking agents, with optimized SiO2 nanoparticle addition (0.3%).
• Industrial granulation of the synthesized gel into expanded particles, followed by physical film coating to manage rapid expansion.
• Performance evaluation of the developed plugging agent under simulated high-temperature and high-salt conditions, assessing expansion multiplier, toughness, stability, and water plugging rate.

Main Results:

• The synthesized nanoparticle coupling polymer gel exhibited a stable three-dimensional network structure with enhanced gel skeleton strength due to SiO2 nanoparticle integration.
• The developed expanded granules demonstrated good long-term stability under harsh conditions (30 days aging at high temperature and salinity), with an expansion multiplier of 3.5 times and a toughness index of 1.61.
• The nanoparticle coupling expanded granule plugging agent achieved a superior water plugging rate of 97.84%, outperforming conventional particle-based plugging agents.

Conclusions:

• The novel nanoparticle coupling expanded granule plugging agent offers a stable and effective solution for water control in fractured and vuggy high-temperature and high-salt reservoirs.
• The optimized formulation and granulation process overcome limitations of traditional gels, enabling easier application and improved performance.
• This technology shows significant potential for enhancing oil recovery efficiency in challenging reservoir environments.