A Novel Modified Petroresin Particle (MPRP) With Enhanced Oil–Water Selectivity for Cold Production in Heavy Oil Reservoirs

Channeling during viscosity reducer flooding in heterogeneous heavy oil reservoirs limits sweep efficiency, while conventional non-selective agents often plug oil-rich zones. To address this, a novel modified petroresin particle (MPRP) with oil–water selectivity was synthesized via graft copolymerization of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) onto dicyclopentadiene-based resin (DCPD). Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy confirmed the successful incorporation of hydrophilic groups while retaining the oil-soluble backbone. MPRP exhibits excellent oil solubility (>84%) and aqueous dispersibility. Under reservoir conditions, temperature and mineralization trigger a 3.6–6.6-fold particle size increase via cohesive expansion, inducing selective plugging in high-permeability water channels to control channeling, while spontaneous dissolution in oil prevents formation damage. Systematic core flooding established the optimal adaptation threshold: 0–50 000 mg/L, 60°C–90°C, 0.1–3.0 D, in situ oil viscosity 1875 mPa·s, and permeability contrast 4.22–11.96. Field-recommended injection parameters increased cumulative recovery from 28.32% to 57.54% in 1.0 D. NMR and micro-visualization revealed that MPRP selectively plugs high-permeability channels, diverting subsequent fluid into low-permeability regions without injectivity impairment. The field test of MPRP achieved effective water production suppression and oil production enhancement, leading to an incremental oil production of 65.22 tons. This work establishes MPRP as a promising agent for conformance control in heavy oil production.