Electric Resonance-Based Depressurization and Augmented Injection in Low-Permeability Reservoirs

To mitigate high pressure under-injection with the purpose of depressurization and augmented injection in low permeability reservoirs, an efficient strategy is proposed based on the electric resonance of the hydrogen bond that is induced by an oscillating electric field. We studied the effects of the electric field on water microscopic structures, dynamics properties, flow, and injection in the nanopore composed of two hydrophilic quartz layers using molecular dynamics simulations and density functional theory calculations. The electric resonance generated by the electric field with a frequency of 16,910 GHz induces the breakage of the hydrogen-bonded network to the largest extent, thus greatly improving the movability of water in the nanopore mainly depending on the following mechanisms: (1) the water tetrahedral structure is destroyed, and water molecules in the first coordinate shell decrease; (2) water diffusion is enhanced, the adsorption residence time of water becomes shorter, and the hydrogen bond retaining intact lasts much shorter; and (3) water flow velocity at the nanopore center and surfaces is greatly increased, the slippage length becomes larger, and the apparent viscosity of water is reduced. Consequently, the electric resonance can effectively reduce the pressure and increase the efficiency for water injection development in low-permeability reservoirs.