Development of a Next-Generation Asphaltene Inhibitor for Sustained Permeability Protection and Extended Squeeze Lifetime in Carbonate Reservoirs

Asphaltene deposition remains one of the most severe causes of formation damage in carbonate reservoirs, leading to rapid permeability loss and costly flow assurance problems. To mitigate these effects, a new low-molecular-weight asphaltene inhibitor, denoted as Inh-C, was developed and systematically evaluated under high-temperature and high-salinity conditions representative of carbonate formations. Static bottle tests conducted at a concentration of 300 ppm yielded an inhibition efficiency exceeding 94 %, outperforming commercial benchmarks such as DBSA, PAO-amine, and Nano-NiO by 14–50 %. Spectroscopic analyses (ATR-FTIR) confirmed that the inhibition originates from multi-site adsorption through π–π-cation and hydrogen-bonding interactions between Inh-C functional groups and asphaltene aromatic cores. Complementary dynamic light scattering and zeta potential measurements performed under dynamic shear conditions (1000 s -1 ) demonstrated excellent colloidal stabilization, maintaining a hydrodynamic diameter (D h ) below 80 nm and surface charge magnitude |ζ| greater than 28 mV. Rheological testing further revealed a decrease of >60 % in non-Newtonian viscosity of asphaltene-laden crude, indicating effective disruption of flocculated structures. Coreflood experiments conducted in cleaned carbonate cores (k 0 = 215 ± 18 mD) showed that more than 94 % of the initial permeability (k/k 0 ) was preserved after 500 pore volumes (PV) of post-flush. HPLC-UV analysis of effluent samples confirmed a sustained inhibitor concentration above 100 ppm for over 435 PV, with desorption behavior well described by a Langmuir-type isotherm (half-life = 328 PV; R 2 = 0.99), reflecting strong yet reversible adsorption onto carbonate surfaces. The dual-mode mechanism of Inh-C, comprising macroscopic floc peptization and nanoscale electrosteric repulsion, accounts for its superior performance across static, dynamic, and flowing systems. By delivering prolonged inhibition at reduced dosage, Inh-C establishes a new benchmark for sustainable asphaltene management, significantly extending squeeze lifetime while minimizing chemical consumption and operational costs in carbonate reservoirs.