Abstract
This study focuses on the tight oil reservoirs of the S Oilfield and establishes a systematic research framework encompassing geological modeling, numerical simulation, parameter optimization, and performance evaluation. It investigates the mechanisms by which key engineering parameters—such as injection timing, pressure, volume, rate, and shut-in duration—affect oil recovery during CO₂ huff and puff processes. The results show that when the reservoir pressure coefficient declines to a certain level and the injection pressure approaches the minimum miscibility pressure, the contact efficiency and miscibility between CO₂ and crude oil are significantly enhanced, leading to reduced oil viscosity and improved fluidity, thereby increasing recovery. Through sensitivity analysis, the study identifies optimal parameter combinations suitable for tight reservoirs and, based on the evolution of interfacial tension, proposes a theoretical basis for scientifically determining shut-in time. This research innovatively develops a CO₂ huff and puff parameter optimization model tailored to the characteristics of tight oil reservoirs, clarifies key control mechanisms, and provides theoretical support and practical engineering strategies for the efficient development of CO₂-based tight oil resources.
