Experiment and Understanding of Oxygen-Reducing Air and Energy-Increasing Huff and Puff in Low Permeability Oilfield

Aiming at the problems of small pore throat, low permeability, difficult injection and production, and poor effect of water injection development in a reservoir with low-ultra-low permeability in an oilfield, in order to solve the contradiction of water flooding and improve the production of a single well, a plan of oxygen-reducing air huff and puff is put forward, which can effectively curb bottom water channeling, prolong the production cycle, effectively improve the crude oil recovery rate of heavy oil reservoirs and obviously improve the development effect. The seepage model of oxygen-reducing air stimulation for oil production wells is established by using reservoir numerical simulation method. According to the geological data and reservoir development characteristics of a single well, the structure, lithofacies and pore saturation model of a single well is established, and the geological reserves and production performance are simulated, and the injection scale and injection parameters of oxygen-reducing air are optimized. By optimizing the scheme of oxygen-reducing air stimulation, oxygen-reducing air is injected to supplement the formation energy after injecting the pre-fluid, so as to improve the formation pressure and the liquid production capacity of a single well. The field test shows that the oxygen-reduced air stimulation technology can maintain and restore reservoir pressure, release elastic energy, and has remarkable effects in improving oil recovery and increasing production in low-permeability oil fields. This achievement provides important technical support for the scale development of low-permeability oil fields.