Abstract:
A summary of research progress of inorganic particle, volume expansion grain, polymer microsphere and other particle profile-control plugging agents is provided, including formula of plugging agents and research progress in compatibility between particles and stratum pore throats. Problems existing in research and application are analyzed, including inorganic particles feature poor washout resistance and short effective period. Water-swelling polymer features high swelling multiple, fast swelling speed, low strength and stability, and is hard to match with stratum. The research on compatibility of particles and stratum pore throats fails to be in full consideration of many affecting factors, such as particle type and properties, grain composition, particle concentration, injection speed, heterogeneity of stratum. And lack of a theoretical model in full consideration of the above affecting factors. Research direction and development trend of particle plugging agents are pointed out on this basis: inorganic particles shall be used in combination with other materials. The use of volume expansion grains requires introduction of rubber, plastic, cation materials as well as temperature-resistant and salt-tolerant monomer as needed, and range of particle size needs to be widened. Multiple affecting factors shall be taken into full consideration for the compatibility between particles and stratum pore throats, and a theoretical model in consideration of multiple affecting factors and actual conditions shall be established. Physical simulation is also required to suit seepage and geological conditions.